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R&S FPS K70 VSA User Manual

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Contents

1. nnn 361 LAY ouEREPEacebWINDog 2 rta rotate 361 361 lt gt 363 LAY out WINDOWSA DENI tarte econtra tete ret etatem etae 363 364 LAY out WINDowsn REPLSCO ie teer trn erreur D SUR ane E Ra aE 364 Bo anro dpi E aeai 364 LAYout ADD WINDow lt WindowName gt lt Direction gt lt WindowT ype gt This command adds a window to the display in the active measurement channel This command is always used as a query so that you immediately obtain the name of the new window as a result To replace an existing window use the LAYout REPLace WINDow command Parameters lt WindowName gt String containing the name of the existing window the new win dow is inserted next to By default the name of a window is the same as its index To determine the name and index of all active windows use the LAYout CATalog WINDow query lt Direction gt LEFT RIGHt ABOVe BELow Direction the new window is added relative to the existing win dow lt WindowType gt text value Type of result display evaluation method you want to add See the table below for available parameter values Ret
2. o Ere x n e ar P c E SENSe EREQUency GENTE STEP erbe EVER KEEN SPESE EEYE KP EXE KEY 291 SENS amp FREQ erncy CENTeFSTEPB AU TO stet et tnt enr p 292 SENSe FREQuency OFFSet SENSe MSRA CAPTure OFFSet ccccsssscccssccsssssnccssnccssscenscssaneeeasesacessecessnetsaecsaneaeaseenecseaeeeanersateesneanes SENSE S WAP o c CAL Culatesm gt BERALG sci ane rnt e re remeare oet texte evoca p CALCulate lt n gt DDEM SPECtrum STATe CALCulate lt n gt DEL Tamarkersim gt AQF Fives rare report ptite wna aae eee de p ene lt gt lt gt 344 CALCulate lt n gt DELTamarker lt m gt MAXimUM 2 00 222 000000 00000000000000000 5 344 CALCulate n DELTamarker m MAXimum NEXT esssssssessissseseenene nennen ntn nhtn 345 CALCulate n DELTamarker m MAXimum RIGHI eeessssesssssesseeseeeeenen ennt rnt enne 345 CALCulate n DELTamarker m MAXimumf PEAK essent 345 CALCulate lt n gt DEL Tamarkersm gt MINIMUM LEFT aeria tct ec e hr ne rtp etc e e cape 345
3. 386 lt gt lt gt 5 387 lt gt lt gt 6 5 5 387 lt gt lt gt 5 388 CAL Culatesnz MARKerems EINK CALCulate lt n gt MARKer lt m gt MAXimum APEak Culatesn gt MARKer lt m gt MAXimumM LEF T iiic notte e ex tena ea EM Led lt gt lt gt lt gt lt gt 1 a i CALCulate lt n gt MARKer lt m gt MAXimum PEAK lt gt lt gt CALCulatesn MARKer m MINimUm NEX T cotta erst thee tp rece CALCulatesn gt MARKer lt m gt MINIMUMIARIG Hie icio treten conecte repone EOM La CALCulate n MARKer m MlINimumy PEAK esee CAL GCulatesn MARKer m arcere trt cem ettet pedet e dpa eter bee dp Ee ne oes
4. 147 o 150 153 Amplitude Settings Amplitude settings affect the signal power or error levels To configure the amplitude settings select the AMPT key and then the Amplitude Con fig softkey VSA Amplitude Scale Unit Reference Leve Value 10 0 dBm Offset 0 0 dB Input Coupling Impedance RF Attenuation lectronic Attenuation Mode Auto Value 20 0 dB Input Output and Frontend Settings Note that amplitude settings are not window specific as opposed to the scaling and unit settings Referenca E 148 L Shifting the Display 22 442 1 5 148 L Setting the Reference Level Automatically Auto Level 148 up e e 149 L Preamplifier option 22 24 149 L Input Coupling ecce tnntntntttntetntntnttntetetetnntne 149 RF cen E HR HERE AREE a tz At 149 L Attenuation Mode 2440 00 149 Using Electronic 2 12 1 1 1 20 0 ken k epu 150 Reference Level Defines the expected maximum reference level Signal levels above this value may not be measured correctly whi
5. 00 326 SENSe DDEMod SEARch PATTern SYNC STATe ett 326 5 20 SENSe DDEMod SEARch SYNC CATalog SENSe DDEMod SEARch SYNC COMMEnt sssssssssssssssssessssssessssssessssseessssevecssssesesssteesssstecsssseesessseessen 5 20 5 2 SENSe DDEMod SEARch SYNC DELete ttt ttti SENSe DDEMod SEARch SYNC IQCThreshold ettet 311 5 5 5 311 SENSe DDEMod SEARch SYNC NAME d SENSe DDEMod SEARch SYNC NSTate 314 SENSe DDEMod SEARch SYNC PATTern ADD ttt ttti 315 SENSe DDEMod SEARch SYNC PATTern REMoVve ettet ttt 315 5 5 5 312 5 5 58 5 312 SENSe DDEMod SEARC
6. Predefined Measurement and Tx Filters A 3 Predefined Measurement and Tx Filters A 3 1 The most frequently required measurement and TX filters required for vector signal analysis according to digital standards are provided by the R amp S FPS VSA application For general information on the use of these filters see chapter 4 1 Filters and Band widths During Signal Processing on page 56 Transmit Filters The transmit filters required for common standards are predefined in the VSA applica tion Table 1 2 Overview of predefined Transmit filters RC Raised cosine RRC Root raised cosine Gauss Gauss filter GMSK Gauss filter convolved with a rectangular filter typically used for MSK Linearized GMSK Standard specific filter GSM EDGE 3GPP TS 45 004 normal symbol rate EDGE Narrow Pulse Shape Standard specific filter GSM EDGE higher symbol rate EDGE Wide Pulse Shape Standard specific filter for GSM EDGE higher symbol rate Half Sine Half Sine filter 25 C4FM APCO25 H CPM Filter for the APCO25 standard Filter for the APCO25 Phase 2 standard APCO25 H DQPSK Filter for the APCO25 Phase 2 standard APCO25 H D8PSK Narrow Filter for the APCO25 Phase 2 standard APCO25 H D8PSK Wide Filter for the APCO25 Phase 2 standard CDMA2000 1X Forward Filter for CDMA ONE forward link TIA
7. lt gt lt gt 5 5 12 372 lt gt lt gt 5 1 5 372 DISPlay WINDow n lt gt 5 317 DISPlayWINDowsn TRAG lt t gt iY SPACING tenet nnt erinnern tena 300 DISPlay WINDows lt n gt TIRACeSTE Y SGALe ortu en Raro o ec 299 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO 330 lt gt lt gt 5 330 DISPlay WINDow n lt gt 5 370 DISPlay WINDow n lt gt 5 299 DISPlay WINDow n lt gt 5 293 lt gt lt gt 5 293 DISPlay WINDow n lt gt 5 300 DISPlay WINDow n lt gt 5 BISPlay WINDowsr TRACES STAT scr ner
8. CALCulate lt n gt LIMit MACCuracy MERRor PMEan RESult lt gt lt gt 11 lt gt 11 0 388 lt gt 11 350 lt gt 11 1 353 lt gt 11 5 388 CALCulate lt n gt LIMit MACCuracy MERRor RMEan STATe CALCulate lt n gt LIMit MACCuracy MERRor RMEan VALue CALOCulate n LIMit MACCuracy MERRor RMEan RESUult essent 388 lt gt 11 5 2 350 lt gt 11 353 lt gt 11 5 388 lt gt 11 5 350 lt g
9. Updating Resultdisplay 163 Result display remote 335 Upper Level Hysteresis eene tots 189 Usable bandwidth Definition Result display Useful length srl dT M 119 User filters Loading 138 User mantal tereti mter eee 8 User QAM Modulation type rrt better t en etn toes 135 User sample rate 22 64 V Vector frequency re E ee ONSE 52 Vector Result eee t rrt toi e ese Mei ooi 53 Video output 5 Window configuratii 201 202 Data SOUNCE cete ti pei reru rre 202 REMOTE ecelesie oodd 364 Result type ie in 202 Result type transformation 22 202 Window title bar information 13 Windows Adding remote eet meet 359 Closing remote 961 364 GONTIQUIIING cere rere a eet 133 Layout remote 24 36 1 Maximizing remote esee 358 Querying remote 960 361 Replacing remote 361 Splitting remote 358 Types remote ue Hense p 359 X X axis p 153 qe T
10. 399 lt gt 399 STATus QUEStionable MODulation n IQRHo EVENt eeeeeeeeee nnn 399 lt gt 399 lt gt 399 STATus QUEStionable POWher EVENItJ 2 cecidere 400 STATus QUEStIonable SY NSEDEVENI gen 400 5 5 nennen nnne rnnt nias 400 STATUS QUESHGnable DIG ENABIB cL tegat enr 400 5 sessi nenne 400 lt gt 400 lt gt 400 lt gt 400 lt gt
11. 1 401 5 5 lt gt 401 R amp S FPS K70 Remote Commands for VSA STATus QUEStionable MODulation n CFRequency PTRansition ccce 401 lt gt 401 lt gt 401 lt gt 1 401 lt gt 401 lt gt 402 5 5 402 STATUs QUEStonable SYNGC PTRaniitlori an a 402 STATus QUEStionable ACPLimit CONDition lt ChannelName gt STATus QUEStionable DIQ CONDition lt ChannelName gt STATus QUEStionable FREQuency CONDition lt ChannelName gt STATus QUEStionable LIMit lt m gt CONDition lt ChannelName gt STATus
12. 345 lt gt lt gt 345 CALOCulate n DELTamarker m MlNimum PEAK eee nnne 345 lt gt lt gt 346 lt gt lt gt 4 4040000 346 lt gt lt gt 346 lt gt lt gt 42 346 lt gt lt gt 346 lt gt lt gt 346 lt gt lt gt 347 gt gt MINIMUM NEXT adidir 347 lt gt lt gt 4 4 4 84 444 347 lt gt lt gt 42 41 41 347 CAL CulatesmsMARKersm siSEAROGO aite npud act Rede toad 347 lt gt lt gt 5
13. 185 Configuration remote 326 Demodulation process cette tnr 90 Enabliiig 186 Loading Predefined iii etr cere etae 186 420 186 gt ntes 186 Measurement ranges Comparison Defio Measurement signal Evaluating icit eterne mr 192 Measurement time Auto Setllngs ue e ttr etre d 189 Min Gap Length on edo celta tale teas 166 Min max values Ol m 152 MIU eicere ce ced 198 Marker positioning iinn itte 198 198 Minimum shift keying MSK Symbol MAPPING iy a 79 MKR gt co 198 MOGACC LilTiitS orit 200 Modulation ConfigulatiOti ne teen 134 Display 12 Errors FSK ed resi te Doe coitu ee 114 Inverted 302 Inverted I Q teg et 157 Map PING 137 Order PC Remote Symbol teretes 137 WY 135 ete eet a 87 Modulation accuracy eI por P Individual results Limit checking Limit
14. Remove Size 31 Comment For details on defining a pattern see example Defining a pattern on page 216 e 172 Biagi 172 MOG 173 E 173 MNT T 173 BE NONE RT 173 L Removing symbols rentis tI rb Ince Ert Ice Fab esp rio aded Rodas 173 eg MER 173 Name Pattern name that will be displayed in selection list Remote command SENSe DDEMod SEARch SYNC NAME on page 314 Description Optional description of the pattern which is displayed in the pattern details Remote command SENSe DDEMod SEARch SYNC TEXT on page 315 Result Range Configuration Mod order The order of modulation e g 8 for an 8 PSK Remote command SENSe DDEMod SEARch SYNC NSTate on page 314 Symbols The pattern definition is a symbol table consisting of one or more symbols The number of symbols is indicated as the Size to the left of the symbol table A scrollbar beneath the input area alows you to scroll through the table for long pat terns The numbers beneath the scrollbar indicate the sequential number of the follow ing symbols from left to right the first symbol the currently selected symbol the last symbol Remote command SENSe DDEMod SEARch SYNC
15. 401 lt gt 401 lt gt 401 lt gt 401 lt gt 1 401 lt gt 401 lt gt 401 5 5 2 401 5 5 5 401 5 5 401 STATUus QUESHomnable DIG P TRAMSIUON aec reae ceder te ee 401 STATus QUEStionable FREQuency PTRansition cai 401 STATus QUEStionable LIMit m PTRansition eeeesseeesseseseee 401 lt gt
16. lt gt 11 5 2 388 lt gt 11 5 350 lt gt 11 1 352 lt gt 11 0 388 CALCulate lt n gt LIMit MACCuracy FERRor RMEan STATe CALCulate lt n gt LIMit MACCuracy FERRor RMEan VALue CALOCulate n LIMit MACCuracy FERRor RMEan RESult eene 388 lt gt 11 5 350 CALCulate lt n gt LIMit MACCuracy FERRor RPEak VALue 952 CALOCulate n LIMit MACCuracy FERRor RPEak RESult esee 388 lt gt 11 6 17 350 lt gt 11 353 lt gt 11 2 388 lt gt 11 5 350 lt gt 11
17. 400 STATus QUEStionable lt gt 401 STATus QUEStionable lt gt 401 _ lt gt 399 STATus QUEStionable MODulation n CFRequency CONDition eese 399 5 lt lt gt 400 5 lt lt gt 401 5 lt lt gt 401 5 lt lt gt 2 399 STATus QUEStionable MODulationn CONDItOn 2 2 ritate cerea erc roe e Pega Fio dun 399 STATus QUEStionable MODulation lt n gt ENABle 5 5 lt gt 22 2 399 5 5 lt gt 2 0 11 1 20 000000 0 000001400000000000 400 5 5 lt gt 0 0 00000 401 5
18. DISPlay WINDow lt n gt TRACe lt t gt STATe State This command turns a trace on and off The measurement continues in the background Parameters State OFF 0 1 RST 1 for TRACe1 0 for TRACe 2 to 6 Example DISP TRAC3 ON Usage SCPI confirmed Manual operation See Trace 1 Trace 2 Trace 3 Trace 4 5 Trace 6 on page 191 See Trace 1 Trace 2 Trace 3 Trace 4 Softkeys on page 192 Working with Markers Markers help you analyze your measurement results by determining particular values in the diagram Thus you can extract numeric values from a graphical display Manual configuration of markers is described in chapter 6 3 Markers on page 194 e Individual Marker SetlliltEs oen e e bee E eb edt 340 e Marker Search and Positioning 00 344 Individual Marker Settings In VSA evaluations up to 5 markers can be activated in each diagram at any time CulatesmMARKersmosNDEE aad ttd send dcr dut vna ecd ig enean 341 CAL Gulate nsMARKereme d INK innana apar 341 lt gt lt gt 9 2 22444444 341 gt dabas enc 341 342 l
19. ee ete eoe rap d e n ne 328 SENSe DDEMod MFILter ALPHa lt MeasFiltAlphaBT gt This command sets the alpha value of the measurement filter Setting parameters MeasFiltAlphaBT numeric value Range 0 1 to 1 0 RST 0 22 Default unit NONE Manual operation See Alpha BT on page 186 SENSe DDEMod MFILter AUTO lt MeasFilterAuto gt If this command is set to ON the measurement filter is defined automatically depend ing on the transmit filter see SENSe DDEMod TFILter NAME on page 283 Setting parameters lt MeasFilterAuto gt ON OFF 1 0 RST ON Manual operation See Using the Transmit Filter as a Measurement Filter Auto on page 186 SENSe DDEMod MFILter NAME Name This command selects a measurement filter and automatically sets its state to ON Setting parameters Name Name of the measurement filter or User for a user defined filter An overview of available measurement filters is provided in chapter A 3 2 Measurement Filters on page 420 Manual operation See Type on page 186 SENSe DDEMod MFILter STATe lt MeasFilterState gt Use this command to switch the measurement filter off To switch a measurement filter on use the SENSe DDEMod MFILter NAME command 11 5 10 Configuring VSA Setting parameters lt MeasFilterState gt 110 Switches the measurement filter off ON Switches the meas
20. 002 ZH 8v MSdv ScOOdV 3NON GZOOdV 002 20 OH 2 48 7 MSdOG 2 STOOdV GZOOdV SEO ISI ye 90 008 0002 VINGO ZHW 882271 1esgo 0002742 _ X Jayi4 L ISI _ a913 XL 3 MeVWOD eunjdeo 008 0002 VINGO ZHW 882271 540 J Seo N u16ue sang 19114 9je1 Buiddew 1426 10 5 104 6 puepuejs Jopjo4 Predefined Standards and Settings s WO4 ous e Jo pJepueis sJeyllp si 104 425 991 x M 00 1898 19 ue2 33g E 000 E a OL OH ZH 00 5 912 199912 _ _ 4 O cS _ eunde5 06 n S 0 OW ZHI Oc 5 ZS ve ASdY cS MH amp eze sdvz 072 860 OW ZHI 02 INvOJesn ZS GAG ve ASdY 9L cS ye nas Meg 9 081 2 s S 0 OW ZHI
21. 377 11 9 2 1 Capture Buffer Results For the result displays based on the capture buffer the command returns the y axis values of the data that is stored in the capture buffer The number of returned values depends on the size of the capture buffer and the sample rate For example a capture buffer size of 500 symbols in combination with a sample rate of 4 would return 2000 level values The scaling of the capture buffer depends on the input source Scaling is relative to the current reference level for RF input Scaling is relative to the full scale level for input The unit is dBm Note that the trace results return only the values for the currently displayed capture buffer range see also chapter 4 8 Capture Buffer Display on page 122 For the Retrieving Results Magnitude Overview Absolute result display this command returns a maximum of 25 000 values corresponding to the displayed trace points You can query the x value that relates to the first value of the y axis using DISPlay WINDow lt n gt TRACe lt t gt X SCALe STARt on page 372 11 9 2 2 Cartesian Diagrams For cartesian diagrams magnitude phase frequency real imag eye diagrams the command returns the y values of the trace The number of returned values is the product of the Result Length and the display points per symbol The unit depends on the specified unit See chapter 11 5 2 6 Scaling and Units on pa
22. esses 287 FSK Calculating Grrors 426 Comipensatior 1 rre rere 426 Deviation error formula 429 Etrrorimodel er rere ect ten 112 EstimatiOf na 113 Measurement deviation formula 429 Modulati nitype rrr 135 Refererice deviation rre een ttes 137 Signal MODES ttn 110 FSK deviation error Compensation FSK reference deviation 429 G Gain distortion 108 Gain imbalance ER REED S 105 Effect 2 105 Formula 428 Preconditions for measurement T 233 GSM Programming example nennen 405 H Hardware settings Displayed eere a 12 Hysteresis Lower Auto level Trigger i e Upper Auto level bandwidth 57 156 correlation threshold Pattermisearell iic rev es 167 data Export file binary data description Export file parameter description Exportting 2 rea Exporting remote Exporting Importifig rero ere tn nette Importing 127 207 Importing remote
23. eene 390 Importing Exporting i Maximum bandwidth eterne 64 sample Tale CU Nd 64 imbalance Red 178 Definition Formula offset Origin Offset Definition 104 Compensating iss Compensation PONG ee 428 I Q pattern search see PatterriseatCl ie qose oe ete i t ses 92 Power ANI GQ 160 Trigger level remote 305 IF frequency Output remote IF OUDUit n res HON REMOTE ii once tacta RR Ue enun 289 IF Power WIG QCM es cete t Dori n i ont neis esa due ens Trigger level remote Importing VQ Gata nett 127 206 207 208 440 data remote niet cens 390 lei iP 207 Impulse response Magnitude result type 37 Phase result type 2s Real Imag result 38 Input Contfig latiOr ceti 142 Configuration remote 287 Coupling 22 22 0 143 149 Coupling 288 Overload remote 288 Die ER Sett
24. pe c E Error messages Expl natloDi eene eive eR RR RA 246 Error model FSK cie ec me etae descen pues ate sud 112 PSK QAM MSK 100 Error vector Data dare eee 16 Definition iu FORMULA 2 citro eorr 425 Result tenete etr mri 16 Error Vector Magnitude EVM iode ode o tno elit oll 102 Formula 425 type mere ee tet 26 RMS peak formulae 428 Errors cett tees 148 Estimation 100 M 113 Points per symbol 101 121 182 PSK QAM niti ee ta eite 101 Ranges 101 Evaluation 162 Specifi rage rennen ter rere ie 163 yc 192 Evaluation methods Data SOUC 14 Evaluation range Configuration 187 Configuration remote 328 x i ai occi ae Display eee Entire result range Start stop values Export format retten trente ees Exporting data data remote nescence gee cle Softkey Tr
25. Meas Signal Meas Data source measurement or reference data Demodulator Offset QPSK Demodulation type ResultMode Trace Result mode x unit sym Unit of the x axis y unit dBm Unit of the y axis Trace Mode Clear Write Trace mode Values 800 Data section for individual trace Number of measurement points 10000 10 3 15 7 10130 11 5 16 9 10360 12 0 17 4 Measured values x value lt 1 gt lt 2 gt lt 2 gt is only available with detector AUTOPEAK and contains the smallest of the two measured values for a measurement point Header section for individual trace Trace 2 Next trace in same window Meas Known Data File Syntax Description File contents Meas Signal Meas Description Data source measurement or reference data Demodulator Offset QPSK Demodulation type ResultMode Trace Result mode x unit sym Unit of the x axis y unit dBm Unit of the y axis Trace Mode Clear Write Trace mode Values 800 Number of measurement points Data section for individual trace Header section for individual window Screen 2 Name of next window Header section for individual trace Trace 1 First trace in second window Data section for individual trace A 5 Known Data File Syntax Description When
26. dO 3933 esind 4720817484 ROLEN BD S 7 edeus esingMoue 41089 _ 0081 Sd asind 3903 usH ys 5221 Y wened LLL 3903 zHisze dO 3603 _ 451 a907 Wvoze 7 YSN 3903 00517 ASNO 3903 srl wvoze pezueeur zHM c amp 0 2 WvOZE v L 026 3903 soy seo u16ue sang 191114 9je1 Budde 1426 uonenjeag ynsey uleyged 10 Jojuojeeg 1g eudiv joquiAg uonejnpo JopJoJ Predefined Standards and Settings s WIO ous e Jo pJepueis sJeyllp si Jo 425 991 x V 9 9 OH E 008 220 OH ZHN v8 9 dd9 1 19102 5 OH VMI3L _ 0 0 sng 992 3 vHlal S 0 OH ZH 8L MSdOG vr i ES yullumoq Ou snonunuoo 0 0 sng 9vc LS vHl3l S 0 OH ZH 8L MSdOG v i SI o4 71081 Wvoc HSH 3904 esna 9pIM C 3903 esingepiM 2 0
27. gt gt TRAGO i Leere coppa ner ea teuer CALCulate n MARKer m X CALGCulatesns MARKer me X SLIMits E EF T scortum ttp eate Meee pz beta Pide CAL Culatesn gt MARKer lt m gt X SLEIMits RIGH Tse c t a t it eee eee lt gt lt gt 5 5 348 CAL GCulatesns MARKerstmi arces ela cepa tiet pp ke Go a dea aoa d dp 372 lt gt lt 2 5 iin iru tr ttr rhetor rr ehh teeth etna rere cr Er tinae 341 CAL Culatesnz MSRA ALINe SEIQW neic aeroporti tnos taut coppa MER da LRL acs ETE 354 lt gt 5 5 eee TEDRE 368 CAL Culatesn gt S TATIstics MODE cierre ttr rate n Ce epu ecc 368 CAL GCulatesns STATistics PRESOL ci inre Beli cn e ere ee E Price ced ee ER rev 296 CALCulate n STATistics SCALe AUTO 2 22 2 0000 297 CALCulatesn STATistics SCALe X BG Our corta dert tp 297 CAL Culatesn gt STAMistics eui irre cd ipe Er cape Hedge 297 CALCu
28. 300 CALCulate n STATistics PRESet This command sets the x and y axis of the statistics measurement to measurement dependent default values Usage Event Manual operation See Default Settings on page 153 Configuring VSA CALCulate lt n gt STATistics SCALe AUTO ONCE This command initiates an automatic scaling of the diagram x and y axis To obtain maximum resolution the level range is set as a function of the measured spacing between peak power and the minimum power for the APD measurement and of the spacing between peak power and mean power for the CCDF measurement In addition the probability scale for the number of test points is adapted To get valid results you have to perform a complete sweep with synchronization to the end of the auto range process This is only possible in single sweep mode Parameters ONCE Example CALC STAT SCAL AUTO ONCE WAI Adapts the level setting for statistical measurements Usage Event Manual operation See Adjust Settings on page 153 CALCulate lt n gt STATistics SCALe X BCOunt lt StatNofColumns gt This command defines the number of columns for the statistical distribution Setting parameters lt StatNofColumns gt numeric value Range 2 to 1024 RST 101 Default unit NONE Manual operation See Quantize on page 153 CALCulate n STATistics SCALe Y LOWer lt Magnitude gt This command defines the lower vertical limit of the diagram Pa
29. 381 lt gt lt gt 5 5 382 lt gt lt gt 5 5 383 lt gt lt gt 5 383 lt gt lt gt 383 lt gt lt gt 384 lt gt lt gt 5 385 lt gt lt gt 5 385 lt gt lt gt 5 385 lt gt lt gt
30. Manual operation See Load User Modulation on page 136 Signal Structure The signal structure commands describe the expected input signal and determine which settings are available for configuration You can define a pattern to which the instrument can be synchronized thus adapting the result range 285 SENSe DDEMod SEARch BURSEtLENGth MINimum 1 285 SENS amp TDDEModtSEARGR BURSESRKIPIEPALELIRG 22222222 ti tna re oa ae Fera ey nho 285 SENSe DDEMod SEARcCh BURSESKIPIRISING 1 2 222 pore itera sere 286 SENSe DDEMod SEARch SYNC CATAalOg sisse nennen nnns 286 SENSeTDDEMod SIGNAEPAT Teri attt rea tea ti cie Bc coner 286 Configuring VSA SENSeJTDDEMed SIGNalDVALUS ice tnam er iter nean teer eerte 286 5 287 287 SENSe DDEMod SEARch BURSt LENGth MAXimum lt gt This command defines the maximum useful length of a burst Only those bursts will be recognized that fall below this length The default unit is
31. lt gt STATus QUEStionable MODulation lt n gt MAGNitude NTRansition 5 5 lt gt 5 lt 5 lt gt 2 399 5 5 lt gt 401 5 5 lt gt 222 399 lt gt 5 400 lt gt 5 401 STATus QUEStionable MODulation lt n gt PHASe PTRansition SIATus QUEStionable POWer PTRALFSILOT ii oco cerva tuac pera ac eara er c Y eta pa ura th 402 STATus QUEStIonable POWer EVENt J s aire eerie ego o rd tek n DE TEPEE 400 STATus QUESIionable SYNG CONDJIOnDn iid eerte aeta oet ace eet tato veras 399 STATus QUEStionable SYNC ENABle eese eene eene nnne etre nennen enne STATus QUEStionable SYNC NTRansition STATus QUEStionable S YNC P TRansiti
32. 214 Avallable e er eec Atlee ae ean 170 Coarse synchronization 183 Compatible 3 erret ren etr en rte 170 Configuration 140 168 jeep 170 Creating eee etre 170 Cups o a Cert 171 Definition remote eee 312 rip 2 171 171 ss 170 Editing tte Deere Gres 170 Enabling 168 171 FINE synchronization 183 aineis snn 217 140 172 rS 141 etc oce 170 Reference for result range 174 Removing from standard 170 Restoring Selected Standard Symbol check 96 Symbol check demodulation process 90 Symbol format nn 173 seg 173 WOFKING et tr emerat 214 Peak search co 198 197 MOOG cutie noite ite pd defen 197 Peaks ete d E Rt 198 Formula Marker positioning cot eret ren 198 pem 198 ec P EEN 198 Phase Distortion effect iaiia ree 109 Formula 42
33. 40 Magnitude Relative n tte 42 amp 15 Modulation accuracy Modulation errors 16 ou 18 Phase EItOt et etd ees 43 Phase Unwtap tnnt ern trt trn 45 Phase Wrap ree tre Dette hr 44 R alimag IQ seien reote Peer 46 Result Sutmiaty 47 SCPI parameters 18 Symbol Table err treten eode leer Vector Frequency Vector VQ Mn Results Retrieving remote esee Updating the display Un Updating the display 335 RF attenuation p IY Manual RF INPUT etre ee rt rea metiri ne rs Overload protection remote 288 e M M 288 RHO 428 RMS average OPM 431 Roll off factor Alpha Measurement filter 186 Transtmit fille critt er tenir tts 138 Rotating Differential PSK Symbol MAPPING rtis 74 Rotating PSK Symbol MAPPING 71 RRC filter KEY M 161 RUN SINGLE 162 Run in SN CP 140 S Sample Tale accetti aire E BASICS te dtes re toe Dee ANE
34. 5 lt gt na 401 STATus QUEStionable MODulation n EVM EVENIt eese 399 STATus QUEStionable MODulation n FSK CONDition sesssssssssssseeseeeeneeenne ener 399 5 0 5 lt gt 2222 0 000000000000000000 400 lt gt eene nennen 401 STATus QUEStionable MODulation n FSK PTRansition esssssssssseseeeeeeeeneeneenne 401 5 lt lt gt 399 STATus QUEStionable MODulation n IQRHo CONDition t STATus QUEStionable MODulation n IQRHo ENABle sssssssssssseseeeeeeeee nennen enne 5 5 lt gt 1 0 STATus QUEStionable MODulation n IQRHo PTRansition essen STATus QUEStionable MODulation n IQRHo EVENI ssessssssssssssseeee 399 5 5 lt gt 2222 399 5 5
35. 5 350 lt gt 11 1 352 CALOCulate n LIMit MACCuracy FDERror 388 lt gt 11 5 2 350 lt gt 11 352 lt gt 11 388 CALCulate lt n gt LIMit MACCuracy FDERror PEAK STATe CALOCulate n LIMit MACCuracy FDERror PEAK RESUIt eese 388 CALOulate n LIMit MACCuracy FERRor PCURrent STATe sese 350 CALOCulate n LIMit MACCuracy FERRor PCURrent VALue essent 352 CALOCulate n LIMit MACCuracy FERRor PCURrent RESUIt esee 388 lt gt 11 6 lt gt 11 CALCulate lt n gt LIMit MACCuracy FERRor PMEan RESult lt gt 11 6 lt gt 11
36. 25 2 22 lt lt tinet rein ntes a Rn ke XR ERR 292 SENSe FREQusncy OFF Sel niea 292 SENSe FREQuency CENTer Frequency This command defines the center frequency Parameters Frequency The allowed range and fmax is specified in the data sheet UP Increases the center frequency by the step defined using the SENSe FREQuency CENTer STEP command DOWN Decreases the center frequency by the step defined using the SENSe FREQuency CENTer STEP command RST fmax 2 Default unit Hz Example FREQ CENT 100 MHz FREQ CENT STEP 10 MHz FREQ CENT UP Sets the center frequency to 110 MHz Usage SCPI confirmed Manual operation See Center frequency on page 146 SENSe FREQuency CENTer STEP lt StepSize gt This command defines the center frequency step size You can increase or decrease the center frequency quickly in fixed steps using the SENS FREQ UP AND SENS FREQ DOWN commands see SENSe FREQuency CENTer on page 291 Configuring VSA Parameters lt StepSize gt fmax iS specified in the data sheet Range 1 to fMAX RST 0 1 x span Default unit Hz Example FREQ CENT 100 MHz FREQ CENT STEP 10 MHz FREQ CENT UP Sets the center frequency to 110 MHz Manual operation See Center Frequency Stepsize on page 146
37. 400 lt gt 400 lt gt 400 lt gt 1 400 lt gt 400 lt gt 400 5 5 400 5 5 5 400 5 5 400 STATus QUESHonable DIGN TRARSIIQFI osi eiin at nre caede 400 400 STATus QUEStionable LIMit lt m gt NTRAnsition ccccccssccessececeesecececeeeseeeeseeeeeeceneeeees 401 STATus QUEStionable LMARgin m NTRansition ecciesie 401 5 5 lt lt gt
38. Manual operation See Q Export page 207 MMEMory STORe lt n gt lQ STATe 1 lt FileName gt This command writes the captured data to a file The suffix lt n gt is irrelevant The file extension is iq tar By default the contents of the file are in 32 bit floating point format Secure User Mode In secure user mode settings that are to be stored on the instrument are stored to vol atile memory which is restricted to 256 MB Thus a Memory full error may occur although the hard disk indicates that storage space is still available To store data permanently select an external storage location such as a USB memory device For details see Protecting Data Using the Secure User Mode in the Data ment section of the R amp S FPS User Manual Parameters 1 lt FileName gt String containing the path and name of the target file Example MMEM STOR IQ STAT 1 R_S Instr user data ig tar Stores the captured data to the specified file Manual operation See Q Export on page 207 Status Reporting System The status reporting system stores all information on the current operating state of the instrument e g information on errors or limit violations which have occurred This infor mation is stored in the status registers and in the error queue The status registers and the error queue can be queried via IEC bus In this section only the status registers bits specific
39. e eee baee INPut C OUPIIDO ceteri tiep m 288 INPut EATT 295 EE M 295 e 296 5 anteater ren dara 294 INP t 7 27 C M 288 INSTr ment CREate DUPLicalte utres 270 INSTrument CREalteREPLACO irent re gu goce 270 INSTrument CREate NEW INS Tumen DELCI astra ec INS EIS 2 e A 271 INS Tr meht RE NITIG cie Serie ea i a EE 272 EEES 272 EAYOUUADDEWINDOW accent rtt ett ce gate n De 359 EAYOuUtCATalog WINDOW s eo toit bee xau e rne Ed 360 LAYout IDENtify WINDow EAYout REMove WINBOWg rrr WINDOW LAOU SPLICE ce came EAYOUUWINDOWSnDSAIDD i cicer vr rte Ug ad E 363 EAYOUUWINDOWSnSIBENIT ii ctr a e 363
40. Be Be ge ge gogo Be Be Se 2 Ge Fe Fe Ge Bo Bo Be Se fo fe Go Se Se Se Ge de Be Yo be ie te Se Do De be be be de de Je Be Be Be Ge Ee de de de Be Ue Ze Ge de Je de Je Be Be Qo fle Co de de de 3e He be te Fig 4 38 Constellation diagram for 1024QAM including the logical symbol mapping hexadecimal the figure shows the upper right section of the diagram only Symbol Mapping 4 3 9 ASK 2ASK OOK ASK stands for Amplitude Shift Keying 2ASK binary is often also referred to as On Off Keying OOK With this type of modulation the information is solely represented by the absolute amplitude of the received signal at the decision points Fig 4 39 Constellation diagram for 2ASK 4ASK 4ASK is a 4 ary Amplitude Shift Keying mapping type With this type of modulation the information is solely represented by the absolute amplitude of the received signal at the decision points Symbol Mapping Fig 4 40 Constellation diagram for 4ASK 4 3 10 APSK With Amplitude Phase Shift Keying APSK modulation the information is represented by the signal amplitude and the signal phase 16APSK Fig 4 41 Constellation diagram for 16APSK including the logical symbol mapping for DVB S2 For DVB S2 16APSK mappi
41. W C i Fig 3 22 Result display for Symbols in hexadecimal mode uum EP SNAM ECC EN M NU User Manual 1176 8516 02 06 51 R amp S FPS K70 Measurements and Result Displays ELE SEES SSS e If a pattern search is active a found pattern is indicated by a green background in the symbol table If during demodulation individual symbols do not match the pattern after all these symbols are indicated by a red frame 4 Symbols Hexadecimal 9 PE QO e gt gt as gt 1010 O e gt O e ph Ld Ld m S S 1 1 1 0 0 0 0 1 1 0 1 1 1 0 0 P ph m m IH m I I HP I IC I m I Ole O Pattern Not Found Remote commands LAY ADD 1 BEL XTIM DDEM SYMB to define the required source type see LAYout ADD WINDow 2 on page 359 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 4 Symbols on page 376 3 2 31 Vector Frequency The instantenous frequency of the source signal as an X Y plot all available samples as defined by the dis
42. 356 DISPlay WINDow lt n gt ZOOM AREA on page 356 Multiple Zoom Ea In multiple zoom mode you can enlarge several different areas of the trace simultane ously An overview window indicates the zoom areas in the original trace while the zoomed trace areas are displayed in individual windows The zoom area that corre sponds to the individual zoom display is indicated in the lower right corner between the scrollbars Remote command DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt STATe on page 357 DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt AREA on page 356 Restore Original Display Restores the original display and closes all zoom windows Remote command DISPlay WINDow lt n gt ZOOM STATe on page 356 single zoom DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt STATe on page 357 for each multiple zoom window Deactivating Zoom Selection mode Deactivates any zoom mode Selecting a point in the display no longer invokes a zoom but selects an object Remote command DISPlay WINDow lt n gt 2007 STATe on page 356 single zoom DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt STATe on page 357 for each multiple zoom window Import Export Functions Q Data Import and Export Baseband signals mostly occur as so called complex baseband signals i e a signal representation that consists of two channels the in phase 1 and the quadrature channel Such si
43. de shades 80 12 14 18 18 f ymbol 0 8 0 6 0 4 0 2 100 Frequency in APCO25 H DQPSK 0 1 1 4 4 20 D D 1 D D 1 1 4 D D D 1 D 1 D D J 1 1 D 1 1 4 1 1 1 D 1 E 1 D D D D D i 0 8 D 0 4 M PME 1 r 1 1 1 1 1 r 1 1 1 1 0 2 4 1 141 0 80 100 gp Frequency in CDMA2000 1X Forward D 1 D 4 1 1 1 1 4 D 1 1 1 1 D D 2 1 2 4 4 4 4 4 20 0 4 4 4 4 19 1 40 D 1 14 4 4 4 4 60 80 100 gp feymbol
44. recuento paco t pata ke I bake ue esiti 302 SENSe DDEMod RLENgth VALue eeeeeen ennt nnns 302 SENSE ON MPG quen utto np n pe prod er 302 WRAGCSSh gt aneda S i aE ka Tn 303 SENSe DDEMod PRATe lt CaptOverSmplg gt Defines the number of samples that are captured per symbol i e the factor by which the symbol rate is multiplied to obtain the sample rate This parameter also affects the demodulation bandwidth and thus the usable bandwidth The sample rate depends on the defined Symbol Rate see chapter 4 2 Sample Rate Symbol Rate and Bandwidth on page 63 Configuring VSA Setting parameters lt CaptOverSmplg gt 418116132 The factor by which the symbol rate is multiplied to obtain the sample rate e g 4 samples per symbol sample rate 4 symbol rate RST 4 Manual operation See Sample Rate on page 156 SENSe DDEMod RLENgth AUTO lt RecLengthAuto gt If enabled the capture length is automatically adapted as required according to the current result length burst and pattern search settings and network specific character istics e g burst and frame structures Setting parameters lt RecLengthAuto gt ON OFF 1 0 RST 1 Manual operation See Capture Length Settings on page 156 SENSe DDEMod RLENgth VALue lt RecordLength gt This
45. 175 arl 175 Symbol Number at Reference Start tente rtt etc once 175 Result Length Defines the number of symbols that are to be demodulated All traces over time are displayed over the result range Remote command SENSe DDEMod TIME on page 317 Reference Defines the reference for the result range alignment The result of the current setting is displayed in the visualization area of the dialog box Capture the capture buffer Burst the detected burst Pattern the detected pattern Remote command CALCulate lt n gt TRACe lt t gt ADJust VALue on page 317 Demodulation Settings Alignment Defines the type of alignment of the result range to the reference source The result of the current setting is displayed in the visualization area of the dialog box Remote command CALCulate lt n gt TRACe lt t gt ADJust ALIGnment DEFault on page 316 Offset Defines the offset of the result range to the alignment reference The result of the cur rent setting is displayed in the visualization area of the dialog box Note Note the following restrictions to this parameter An offset lt 0 is not possible if you align the result range to the left border of the capture buffer An offset that moves the pattern outside the result range is not allowed For exam ple if you align the result to the left border of the pattern only offsets S 0 are allowed Otherw
46. FREQuency Frequency Absolute COMP Vector CONS Constellation IEYE Eye Diagram Real 1 QEYE Eye Diagram Imag Q FEYE Eye Diagram Frequency CONF Constellation Frequency COVF Vector Frequency RCONStellation Constellation Rotated RSUMmary Result summary BERate Bit error rate GDELay Frequency Response Group Delay Example See chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Manual operation See Result Type on page 202 Configuring the Result Display CALCulate lt n gt STATistics CCDF STATe lt AddEvaluation gt This command switches the measurement of the statistical distribution of magnitude phase or frequency values on or off Setting parameters lt AddEvaluation gt ON OFF 1 0 RST 0 Manual operation See Result Type Transformation on page 202 CALCulate n STATistics MODE lt StatisticMode gt This command defines whether only the symbol points or all points are considered for the statistical calculations Setting parameters lt StatisticMode gt SONLy INFinite SONLy Symbol points only are used INFinite All points are used RST SONLy Manual operation See Oversampling on page 203 DISPlay WINDow lt n gt ITEM LINE VALue lt SingleValue gt DISPlay WINDow lt n gt ITEM LINE VALue lt SingleValue gt This commands switches between the whole Result Summary and the
47. Message Sync Prefers More Valid Symbols eene Message Sync Prefers Longer 0 10 2 1 1 Message Result Ranges R amp S9FPS K70 Optimizing and Troubleshooting the Measurement Message Burst Not Found The Burst Not Found error message can have several causes Burst search is active but the signal is not bursted Start 0 sym 18 03 2010 09 53 45 Fig 10 1 Example for active burst search with continuous signal Solution Select Continuous Signal as the signal type For more information see Signal Type on page 139 Signal is bursted but bursts have not been captured completely The burst search can only find bursts that start and end within the capture buffer It ignores bursts that are cut off Man CapBuf 1 Start 0 sym Fig 10 2 Example for incomplete burst capture Solution Change the trigger settings and or enlarge the capture length For more information see chapter 5 6 Signal Capture on page 154 The current measurement is being performed on a burst that has not been captured completely mum SSS ECCE M NU User Manual 1176 8516 02 06 247 R amp S FPS K70 Optimizing and Troubleshooting the Measurement Mag CapBuf 1 NI Start 0 sym Fig 10 4 Example for measurement on complete burst capture Solution Change
48. RST OFF Example CALC DELT2 ON Turns on delta marker 2 Manual operation See Marker State on page 195 See Marker Type on page 196 Analysis CALCulate lt n gt DELTamarker lt m gt TRACe Trace This command selects the trace a delta marker is positioned on Note that the corresponding trace must have a trace mode other than Blank If necessary the command activates the marker first Parameters Trace Trace number the marker is assigned to Example CALC DELT2 TRAC 2 Positions delta marker 2 on trace 2 CALCulate lt n gt DELTamarker lt m gt X Position This command moves a delta marker to a particular coordinate on the x axis If necessary the command activates the delta marker and positions a reference marker to the peak power Example CALC DELT X Outputs the absolute x value of delta marker 1 Manual operation See X value on page 195 CALCulate lt n gt DELTamarker lt m gt Y This command queries the relative position of a delta marker on the y axis If necessary the command activates the delta marker first To get a valid result you have to perform a complete measurement with synchroniza tion to the end of the measurement before reading out the result This is only possible for single measurement mode See also INITiate lt n gt CONTinuous on page 333 The unit depends on the application of the command Return values lt Position gt Position of the delta marker in relation
49. iecur iren cri i innert SANESE NEES 7 1 2 Documentation 8 1 3 Typographical 9 2 Welcome to the Vector Signal Analysis Application 10 2 4 Starting the VSA 444 00 10 2 2 Understanding the Display Information eene 11 3 Measurements and Result 14 3 1 Evaluation Data Sources in 14 3 2 Result Types mM VIA reU IER eiie 18 3 3 Common Parameters in enne nnne nnn nnne nnns 54 4 Meas rement 5 a anenai ea iaaa 56 4 1 Filters and Bandwidths During Signal Processing eene 56 4 2 Sample Rate Symbol Rate and 63 EA MEEAUgBNEgnn 67 4 4 Overview of the Demodulation 88 4 5 Signal Model Estimation and Modulation 100 4 6 Measurement R
50. jr eec a Preconditions for measurement Quick Config Dc 192 R Range PO iaoiai eii N 153 Range per division 152 Raw data Epon g rem 193 Real Imag ert erant hen us i nido 46 Receive tete hec ato 58 Record length Definition Relationship to sample rate Recording tool Known dala nido rudem reat 219 Reference Fes lbrange ener etre treten 174 Reference deviation DEMHON Matis 111 ESI Loss aor 59 Reference level eite 148 Auto level 148 188 Offset 148 Unit 148 bU 148 Reference position POI i a 153 Y axis usse 152 Reference signal se 101 Demodulation process 90 Evaluating 192 90 Reference value X axis Y axis Refresh 162 Refreshing MSRA applications corren MSRA applications remote p SOflKGy rear cer ees Remote commands Basics On SYMAX eri tegens 264 Boolean values 268 Ca
51. 225 Defining remote aS 350 Modulation 225 Retrieving check results remote 388 Linear average e 431 Lines Limit Checking uu corte n dec 199 Loading Settings THES 05 524 een mere 131 Low ISI filters Frequency 435 Lower Level Hysteresis 189 M Magnitude Formula e mese 425 Magnitude absolute 39 Magnitude Absolute bte doro eene b ON Dn 39 122 Magnitude error 103 Formula 425 42 43 RMS peak formulae 428 429 Magnitude Overview Absolute DY tco toe Rae 40 122 Magnitude Relative Result LY 6 c US 42 Mapping see Symbol mapping Mapping wizard mapwiz Market to icit to tre ia Sei i Markers Absolute peak uude oit re t eine EB n n Rcx 198 Assigned tabe icc orm res 196 Configuring S tust Hv us inde TEE 196 Delta markers 2 196 General settings remote 344 Minimutm
52. Rho Power The following results that are based on internal estimation algorithms see chapter 4 5 Signal Model Estimation and Modulation Errors on page 100 are calculated over the Estimation range see also chapter 4 5 1 2 Estimation on page 101 Table 3 3 Results calculated over the estimation range PSK MSK QAM FSK Carrier Frequency Error Symbol Rate Error FSK Deviation Error Symbol Rate Error Offset FSK Measurement Deviation Imbalance Carrier Frequency Error Gain Imbalance Carrier Frequency Drift Quadrature Error Amplitude Droop Current value In the Current column the value evaluation for the current evaluation is displayed For example the EVM Peak value in the current sweep corresponds to the peak of the trace values within the evaluation range for the current sweep as indicated by marker 1 in figure 3 20 R amp S FPS K70 Measurements and Result Displays 2 Result Summary Current StdDev 95 ile Units EVM RMS 0 32 0 32 0 3 5 00 9j Peak 0 84 0 84 0 8 0 00 RMS 49 87 49 87 49 8 5 00 41 54 1 0 00 Phase Error RMS 0 15 y 9 1 0 00 Peak 0 48 8 0 48 0 00 Magnitude Error RMS 0 18 18 0 1 9 00 Peak 0 53 0 53 2 2 00 Carrier Frequency Error 178 54 178 54 8 54 0 00 Symbol Rate Error 0 00 Rho 0 999 990 05 0 Os 90 0 000 000 1 0 Offset 66 07 2 0 Tmbalance 65 51 1 5 00 Imbalance
53. eene 212 How to Analyze the Measured nnn 221 Measurement 228 Connecting the Transmitter and 1 1 228 Measurement Example 1 Continuous QPSK 228 Measurement Example 2 Burst GSM EDGE 235 Optimizing and Troubleshooting the Measurement 244 Flow Chart for Troubleshooting eese nnne nnn nn 244 Explanation of Error nennen nennen 246 Frequently Asked Questions essen nennen nennen nennen na 255 Obtaining Technical 4 444 262 Remote Commands for 6 1 264 lT oiie REE 264 Common Suffixoes ecciesie tese 269 User Manual 1176 8516 02 06 4 11 3 Activating Vector Signal 12 11 1113 nnne nnne nnne 269 14 Digital Standards
54. rec ed beber cec p ee gv 246 Frequently Asked entren nennen 255 Obtaining Technical 262 Flow Chart for Troubleshooting If you experience a concrete measurement problem you might want to try solving it with the help of the flow chart Troubleshooting Overview Flow Chart for Troubleshooting Press Preset in order to start from a known state Y Check the following parameters at the DUT and the K70 Demodulation Failed dications are e g Sync Failed Unstable Message in the Status Bar The EVM is really bad The measurement Constellation does not look at all like a constellation Y To make sure you realize once the problem is fixed Switch on the EVM trace and keep an eye on it Center frequency Reference Level overload Symbol rate Transmit filter Check the Modulation Type measurement Sideband inversion Swap IQ Mag CapBuffer e colored bar Result Range in a range where you expect the signal to have the set modulation no Try to increase Run In and Run Out in the Signal Description gt Signal Structure dialog 260 417 ns 260 417 ns See part 2 yes Is your signal bursted C Sync prefers more valid symbols Is Sync prefers more valid yes
55. 257 Problem The Vector result display and the Constellation result display look dif TOTBTID 257 Problem The Constellation measurement result display has a different number of constellation points in the R amp S FSQ K70 and the R amp S 5 70 257 Problem the MSK FSK signal demodulates on the R amp S FSQ K70 but not on the R amp S FPS K70 or Why do have to choose different transmit filters in the R amp S FSQ And the RSS EPS IKJI nre ipee Hte peer ne deb eei FEE Pera 258 Problem The EVM trace looks okay but the EVM in the result summary is significantly SISTI ISI LL tL 258 Question Why isn t the FSK Deviation Error in R amp S FPS K70 identical to the FSK DEV ERROR in R amp S FSQ KTO itte ae eniti net deese 260 Problem The PSK QAM Signal shows spikes in the Frequency Error result display 261 Question The y axis unit for the spectrum of the measurement signal can be chosen to dB What level is this relative 12 261 Question How can get the demodulated symbols of all my GSM bursts in the capture buffer IN remote preme se ningun 261 Question Why do the EVM results for my FSK modulated signal look wrong 262 Problem The trace is not entirely visible within the measurement window Solution
56. Remote command D 2 on page 309 Measuring only if burst was found If enabled measurement results are only displayed and are only averaged if a valid burst has been found When measuring bursted signals that are averaged over several measurements it is recommended that you enable this option so that erroneous mea surements do not affect the result of averaging Remote command DDEM SEARCh E t MODE on page 309 User Manual 1176 8516 02 06 165 Burst and Pattern Configuration Burst Configuration The conditions under which a burst is detected in the captured data can be configured either manually or automatically according to the defined signal structure settings see Burst Settings on page 140 Remote command SENSe DDEMod SEARch BURSt CONFigure AUTO on page 309 Search Tolerance Burst Configuration Defines the number of symbols that may differ from the burst length without influencing the burst detection A search tolerance of 5 for example with a minimum and maxi mum burst length of 100 will detect bursts that are 95 to 100 symbols long The mini mum and maximum burst length is defined in the Signal Structuresettings Note Due to the fact that the VSA does not have knowledge of the ramp length there is an uncertainty in the burst search algorithm Thus setting this parameter to O will result in a failed burst search for most signals Remote command SENSe DDEMod SEARch
57. 399 lt gt 399 lt gt 1 399 5 lt gt 399 lt gt 399 Status Reporting System STATus QUESHonable POWerCONDIEOI aiia nania un ene nent annee 399 STATus QUEStionable SYNC GON DITION oncacs aE 399 STATus QUEStionable ACPLimit EVENIt sees 399 STATUS QUESHomable DIOREVEN adactus 399 STATus QUEStionable FREQuencyDEVENI 2 22 iiio rotor tere deese 399 STATus QUEStionable LIMitemio EEVENI 2 tenute 399 lt gt 399 STATus QUEStionable MODulation n EVENIt J cessere 399 lt gt 399 lt gt
58. R amp S Recording Tool for Sequences amp Configuration VISA TCPIP localhost Results Analyzed Sequences 33 Modulation PSK Format 8 ResultLength 148 Different Sequences 83 Last New Sequence Found 0 ago Throughput 0 72 kSymbols s Store for K70 Run Stop Reset 3 Start a measurement in the VSA application 4 the tool window select Run The tool records the demodulated data sequences The following result information is provided by the tool during recording e Analyzed Sequences number of data sequences analyzed since the tool was started How to Perform Customized Measurements e Different Sequences number of unique sequences detected in the measured data e Last New Sequence Found time that has passed since the most recent unique sequence was detected e Throughput current data processing speed of the tool Note that while the tool is running the R amp S FPS is set to remote mode i e the manual interface is not available As soon as the tool is closed the remote mode is automatically deactivated 5 When all known possible sequences have been detected or when a significantly large amount of time has passed so as to assume no more sequences will be detected stop the tool by selecting Stop 6 e Ifthe results are acceptable select Store for K70 to store a valid xml file with the recorded data sequences on the instr
59. Rea Ra SENSe DDEMod MFILter STATe SENSe DDEMod MSK F ORMal ornetur o reri nter re ER EYE FEX EUREN EXE seta SENSe DDEMod NORMalize ADRYOOD entrer inh te re Fe d ie dene o EM ene uo 324 SENSe DBDEMod NORMAalIIZe GP DISITU cci cesi en eph o a EE 324 SENSe DDEMod NORMalize CHAINnel oia totae rn tt teneo ninh EXE eren 324 SENSe DDEMod NORMalize FDERTOE 22 enti ctr tertio th th hn 324 SENSe IDDEMod NORMalize lOIMbalance soit er toe enne hee la 325 SENSe DDEMod NORMalize IQOFfset SENSe DDEMod NORMalize SRERror SENSe DDEMod NORMalize sicca ca ooh et rn e E vx ba DE oe SENSe DDEMOd OP Timization ocior e irren tener rt rre ern PER SENSe IDDEMOGQ PRATS6 i a e Ceca Porto gl at D C ee eae 5 ich beet a SENSe DDEMod PRESetRLEVel cett ttt ttt ttt SENSe DDEMod PRESet STANdard SENSe DDEMod PSK FORMat ettet ttt ttt ttt ttt otto sss SENSe DDEMod PSK NSTate ttt ttt ttt ttes 5 ttt ttt ttt ttt ttt
60. Ref Power Maximum power of the reference signal at the symbol instants E User Manual 1176 8516 02 06 181 Demodulation Settings Mean Ref Power mean power of the reference signal at the symbol instants Mean Constellation Power Mean expected power of the measurement signal at the symbol instants e Constellation Power The maximum expected power of the measurement signal at the symbol instants Remote command SENSe DDEMod ECALc MODE on page 318 Optimization Determines the method used to calculate the result parameters The required method depends on the used standard and is set according to the selected standard by default Minimize RMS Optimizes calculation such that the RMS of the error vector is mini Error mal Minimize Optimizes calculation such that EVM is minimal EVM Remote command SENSe DDEMod OPTimization on page 325 Estimation Points Sym During synchronization the measurement signal is matched to the reference signal and various signal parameters are calculated You can define how many sample points are used for this calculation at each symbol For more information on estimation points per symbol see chapter 4 7 Display Points vs Estimation Points per Symbol on page 121 You can set the estimation points manually or let the VSA application decide how many estimation points to use If automatic mode is enabled the VSA application uses the following settings
61. SENSe DDEMod FAC Tory VALue 5 rr ertet nt tror tr SENS DBEMod FIl TerAUPHa e tta eet ett test cre t ee ta Ges SENSe HDDEMeod FIBT er S AT ico utra e de EUR eae hec OR ee SENSe IDDBEMOQ FORMAal bea DERE XE VERE nin SENS amp DBEMod F SK NS T te c ttti teet er etre a RE CER HM center ated SENSE PDEMOdIF SY NGAW TO 5656 ice chess ed acad D vec b Dv eie ren QOL SENSe DDEMod FSYNc LEVel SENSe DDEMod FS YNC RESUlt uco etre nct duvet aas epai aiea 323 sie eoi Er ts eser aen exa debes PEE x vede 323 SENSe DDEMod KDA Ta S TAT6 iacit enhn eren a a RR CER EXE 323 SENSe DDBEMOQG KDAT a NAME S i err retenti tpe etc erg eae ied epe eae 324 SENSeDDEMod MAPPing ATalOGg oic to eer he i oco Ub cu ert acu NER ERI do 279 SENSe DDEMod MAPPinig VALUe cote tt nere thia et crean th er en renes 279 SENSe DDEMod MFILter ALPHa Ag ISENS IDDE MOQ MFL TAUT Os socii trot icta md vm be td e ke Eon DUELO atid SENSe IDDBEMOGQCMEIE teE NAME cott redii gerere HERE FE cea i denen aren SENSe DDEMod MElIbter USER rete te trn enne hr aerei i Ea Ferme Eten n
62. imbalance error Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic MERRor type This command queries the results of the magnitude error measurement of digital demodulation Query parameters type none RMS magnitude error of display points of current sweep AVG Average of RMS magnitude errors over several sweeps PAVG Average of maximum magnitude errors over several sweeps PCTL 9596 percentile of RMS magnitude error over several sweeps PEAK Maximum EVM over all symbols of current sweep PPCT 95 percentile of maximum magnitude errors over several Sweeps PSD Standard deviation of maximum magnitude errors over several Sweeps RPE Maximum value of RMS EVM over several sweeps SDEV Standard deviation of magnitude errors over several sweeps TPE Maximum EVM over all display points over several sweeps Usage Query only Retrieving Results CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic MPOWer type This command queries the results of the power measurement of digital demodulation Query parameters type none power measurement for current sweep AVG Average of power measurement over several sweeps RPE Peak of power measurement over several sweeps SDEV Standard deviation of power measurement PCTL 95 percentile value of power measurement Usage Query only CALCulate n MARKer m FUNCtion DDEMod STATistic OOFFset type This command queries the resul
63. 388 CALCulate lt n gt BERate Format Queries the Bit Error Rate results The available results are described in chapter 3 2 1 Bit Error Rate BER on page 20 Query parameters Format Specifies a particular BER result to be queried If no parameter is specified the current bit error rate is returned The parameters for these results are listed in table 11 3 Table 11 3 Parameters for BER result values Result Current Min Max Acc Bit Error Rate CURRent MIN MAX TOTal Total of Errors TECurrent TEMIN TEMAX TETotal Total of Bits TCURrent TMIN TMAX TTOTal CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic ADRoop lt type gt This command queries the results of the amplitude droop error measurement per formed for digital demodulation The output values are the same as those provided in the Modulation Accuracy table see chapter 3 2 29 Result Summary on page 47 Retrieving Results Query parameters type none Amplitude droop in dB symbol for current sweep AVG Amplitude droop in dB symbol evaluating the linear average value over several sweeps RPE Peak value for amplitude droop over several sweeps SDEV Standard deviation of amplitude droop PCTL 95 percentile value of amplitude droop Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic ALL The command queries all results of the result summary as shown
64. 5 388 lt gt 11 5 2 350 CALCulate lt n gt LIMit MACCuracy EVM PMEan 352 lt gt 11 2 388 CALCulate lt n gt LIMit MACCuracy EVM PPEak STATe CALOulate n LIMit MACCuracy EVM PPEak RESUIt sess ennt 388 lt gt 11 350 lt gt 11 352 lt gt 11 0 388 lt gt 11 5 350 lt gt 11 352 lt gt 11 2 388 lt gt 11 5 2 350 lt gt 11 352 lt gt 11 2 2 388 CALOulate n LIMit MACCuracy FDERror
65. A 6 1 Formulae 770 173 705 631 011 235 507 476 330 522 177 177 171 117 777 177 717 717 111 615 527 046 104 004 106 047 125 415 723 344 241 264 773 111 337 446 514 600 67 Data lt RS VSA KNOWN DATA FILE Formulae e Trace based Evaluatloris 2 ortnm endet etti etd 425 e Result Summary Evaluations rnit reader eee dea 427 e Statistical Evaluations for the Result 430 431 e Analytically Calculated n ec en ave ect teda 431 e Standard Speciflo Filt ts 1n Ie ect oe EAE ieee 432 Trace based Evaluations The trace based evaluations all take place at the sample rate defined by the Display Points Per Symbol parameter see Display Points Sym on page 203 The sampling instants at this rate are referred to as t here i e t n Tp where equals the duration of one sampling period at the sample rate defined by the Display Points Per Symbol parameter Test parameter Formula Error vector EV MEAS REF t Error Vector Magnitude EVM EV t EVM t ive 2 with the normalization contant C depends on your setting By default C is the mean power of the reference signal c EY err T duration of symbol periods Magnitude Mag yas t MEAS o Mager USE Phaseyg4s Z MEAS Phases Z REF t F
66. During transmission disturbances in the transmission channel may cause distortions in the input signal at the R amp S FPS Such influences are included in the EVM calculation However if the ideal reference signal can be estimated with sufficent accuracy by the R amp S FPS e g using the equalizer the channel distortions can be compensated for and deducted from the EVM 4 5 2 FSK Modulation Signal Model Frequency shift keying FSK involves the encoding of information in the frequency of a transmitted signal As opposed to other modulation formats such as PSK and QAM the FSK process is a non linear transformation of the transmitted data into the trans mitted waveform Signal Model Estimation and Modulation Errors A sequence of symbols 5 are modulated using a frequency pulse g t to form the instantaneous frequency of the transmitted complex baseband waveform denoted by frer t and defined as fase 1 3 sig iT where fsymp 1 T is the symbol rate and h is a scaling factor termed the modulation index The transmitted or reference FSK signal is formed by frequency modulation of the instantaneous frequency 42 frer udu el Pace REF t e where pe t denotes the phase of the transmitted waveform In the VSA application continuous phase FSK signal is assumed which is ensured by the integral in the expression for REF t A graphical depiction of the reference waveform generation is shown below in figure
67. Frequency in Formulae CDMA2000 1X Reverse 20 2 1 2 4 4 4 4 4 4 r 4 D 4 D D 1 4 D r 4 4 4 D i 4 4 4 4 4 L D 4 D r 4 DL 4 1 D ot 0 4 4 4 42 20 40 gp Pessac 14 4 4 4 80 100 f ymbol Frequency in EDGE Narrow Pulse Shape D 4 1 8 2 ebd uiu q L D 1 D D 20 eee o b al 60 80 gp 4 4 4 04 08 08 12 14 1 6 Frequency in f ymbol 0 2 100 EDGE Wide Pulse Shape 4 8p 4 7 4 D q D r D 4 apnyubeyy 4 4 Frequency in Data File Format iq tar Half Sine Magnitude dB D 4 D D
68. This command defines the trigger hysteresis which is only available for IF Power trig ger sources Configuring VSA Parameters lt Hysteresis gt Range dB to 50 dB RST 3 dB Example TRIG SOUR IFP Sets the IF power trigger source TRIG IFP HYST 10DB Sets the hysteresis limit value Manual operation See Hysteresis on page 160 TRIGger SEQuence LEVel EXTernal lt port gt lt TriggerLevel gt This command defines the level the external signal must exceed to cause a trigger event Suffix lt port gt Selects the trigger port 1 trigger port 1 TRIG IN connector on rear panel 2 trigger port 2 TRIG AUX connector on rear panel Parameters lt TriggerLevel gt Range 0 5V to 3 5 V RST 1 4 V Example TRIG LEV 2V Manual operation See Trigger Level on page 160 TRIGger SEQuence LEVel IFPower lt TriggerLevel gt This command defines the power level at the third intermediate frequency that must be exceeded to cause a trigger event Note that any RF attenuation or preamplification is considered when the trigger level is analyzed If defined a reference level offset is also considered Parameters lt TriggerLevel gt For details on available trigger levels and trigger bandwidths see the data sheet RST 10 dBm Example TRIG LEV IFP 30DBM Manual operation See Trigger Level on page 160 TRIGger SEQuence LEVel IQPower lt TriggerLevel gt This command defines the magnitude the
69. lt gt 5 389 lt gt 1 1 8 4 4220004 350 lt gt 16 354 lt gt 389 CALCulatesn LIMIEMACQGuracy S eheu py ee sg ba ex EXER XR 349 CALCulate lt n gt MARKer lt m gt AOFF lt gt lt gt 5 378 lt gt lt gt 5 12 379 lt gt lt gt 5 379 lt gt lt gt 380 CALCulate n MARKer m FUNCtion DDEMod STATistic F DERror sse 380 lt gt lt gt 5
70. 42 04 Output input P ower 009 EL 2 9 2 DM 9 6 4 2 0 Hepat Pamer lag Tranefer Function Analyzer b m Output Power Input P ower lag e e 48 2 30 8 4 4 2 0 heut Power log A logarithmic display of the amplitude transfer functions is shown in table 4 18 The analyzer trace is shifted against the transmitter trace by this scale factor Signal Model Estimation and Modulation Errors Phase Distortion Table 4 19 Effect of nonlinear phase distortions Nonlinear distortions phase distortion transmitter Phase distortion analyzer Phase Distortion Tranarm ter 0 01 02 OF 04 Res 0 06 0 06 Phase Dianon Analyzer 0 02 03 04 05 05 07 08 The effect of nonlinear phase distortions on a 64QAM signal is illustrated in table 4 19 only the first quadrant is shown The transfer function is level dependent the highest effects occur at high input levels while low signal levels are hardly affected These effects are caused for instance by saturation in the transmitter output stages The sig nal is scaled in the analyzer so that the average square magnitude of the error vector is minimized The second column shows the signal after scaling Table 4 20 Phase transfer functions Nonlinear distortions phase distortion transmitter Phase distortions analyzer Phase Transir Function Tranentl
71. 5 85 2 SENSe DDEMod QPSK FORMat SENSe DDEMOod RLENGth AUTO ttt SENSe DDEMod RLENgth VALue x 5 5 9 SENSe DDEMod SEARCh BURSEtAUTO ttt 309 SENSe DDEMod SEARCch BURSt CONF igure AUTO ettet 309 SENSe DDEMod SEARCh BURSEGLENGth MlINimum cct 309 5 5 amp 5 1 285 SENSe DDEMod SEARCh BURSELENGIh MlNimum cette 285 SENSe DDEMod SEARch BURSt MODE SENSe DDEMod SEARCh BURSESKIP FALLing eet ttt 285 SENSe DDEMod SEARCh BURSESKIP RISing ttti 286 5 5 5 amp 58 58 310 SENSe DDEMod SEARch BURSt TOLerance 310 5 2 307 5 20 ttt ttti 374 5 20 ttt 310 5
72. FUNCtion DDEMod STATistic FSK MDEViation 382 CALCulate n MARKer m FUNCtion DDEMod STATistic FSK RDEViation 383 CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic GIMBalance 383 CALCulate n MARKer m FUNCtion DDEMod STATistic IQIMbalance 383 lt gt lt gt 384 lt gt lt gt 385 CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic 7 385 lt gt lt gt 385 lt gt lt gt 386 lt gt lt gt 387 lt gt lt gt 387 lt gt lt gt
73. Meas filter PSK QAM UserQAM MSK The and the Q part of the measurement and the reference signal are filtered with this filter FSK The instantaneous frequency of the measurement reference signal are filtered In many applications the measurement filter is identical with the ISI filter User Manual 1176 8516 02 06 58 Filters and Bandwidths During Signal Processing The receive filter ISI filter is configured internally depending on the transmit filter The goal is to produce intersymbol interference free points for the demodulation The reference filter synthesizes the ideal transmitted signal after meas filtering It is calculated by the analyzer from the above filters convolution operation Transmit filter Meas Filter Typical combinations of Tx and Meas filters are shown in table 1 4 they can be set in the VSA application using Meas filter AUTO see Using the Transmit Filter as a Measurement Filter Auto on page 186 If RC raised cosine RRC root raised cosine and Gaussian filters are used the Alpha RC RRC filters or BT Gaussian fil ters parameters must be set in addition to the filter characteristic roll off factor Typi cally the Alpha BT value of the measurement filter should be the same as that of the transmission filter 4 1 4 Measurement Filters The measurement filter can be used to filter the following two signals in the same way the measurement signal after coarse frequ
74. SENSe ADJust CONFigure DURation on page 330 Upper Level Hysteresis When the reference level is adjusted automatically using the Auto Level function the internal attenuators and the preamplifier are also adjusted In order to avoid frequent adaptation due to small changes in the input signal you can define a hysteresis This setting defines an upper threshold the signal must exceed compared to the last mea surement before the reference level is adapted automatically Remote command SENSe ADJust CONFigure HYSTeresis UPPer on page 331 Lower Level Hysteresis When the reference level is adjusted automatically using the Auto Level function the internal attenuators and the preamplifier are also adjusted In order to avoid frequent adaptation due to small changes in the input signal you can define a hysteresis This setting defines a lower threshold the signal must fall below compared to the last mea surement before the reference level is adapted automatically Remote command SENSe ADJust CONFigure HYSTeresis LOWer page 331 Auto Scale Once Auto Scale Window If enabled both the x axis and y axis are automatically adapted to the current mea surement results only once not dynamically in the selected window To adapt the range of all screens together use the Auto Scale All function Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO ONCE on page 330 Auto Scale All Adapts
75. SENSe FREQuency CENTer STEP AUTO lt LinkMode gt Defines the step width of the center frequency Setting parameters lt LinkMode gt ON OFF 1 0 ON Links the step width to the current standard currently 1 MHz for all standards OFF Sets the step width as defined using the FREQ CENT STEP command see SENSe FREQuency CENTer STEP on page 291 RST 1 Manual operation See Center Frequency Stepsize on page 146 SENSe FREQuency OFFSet lt Offset gt This command defines a frequency offset If this value is not 0 Hz the application assumes that the input signal was frequency shifted outside the application All results of type frequency will be corrected for this shift numerically by the application See also Frequency Offset on page 147 Note In MSRA mode the setting command is only available for the MSRA Master For MSRA applications only the query command is available Parameters Offset Range 100 GHz to 100 GHz RST 0 Hz Example FREQ OFFS 1GHZ Usage SCPI confirmed Manual operation See Frequency Offset on page 147 Configuring VSA 11 5 2 4 Amplitude Settings Amplitude and scaling settings allow you to configure the vertical y axis display and for some result displays also the horizontal x axis Useful commands for amplitude settings described elsewhere INPut COUPling on page 288 SENSe ADJust LEVel on page 332 Remote commands exclusive
76. Start 0 sym Stop 8000 sym Fig 9 3 Default window layout for Measurement Example 1 9 2 3 Changing the Display Configuration 1 To change the window layout i e the display configuration do one of the following e Select the Display Config softkey in the main VSA menu e Select the Display Configuration block in the Overview only if Specifics for option is disabled Select the SmartGrid icon from the toolbar 2 Replace window 1 by an eye diagram of the inphase component of the measure ment signal a Select Meas 4 data source from the SmartGrid selection bar and drag it over window 1 i Close the SmartGrid mode by selecting the Close icon at the top right corner of the toolbar c Select the Window Config softkey d Select the result type Eye Diagram Real 1 3 Close the dialog to take a look at your new display configuration mum EINEN DAN MN V User Manual 1176 8516 02 06 232 Measurement Examples R amp S FPS K70 el 9 2 4 Navigating Through the Capture Buffer Using the R amp S FPS VSA application you can navigate through the capture buffer i e control which part of the capture buffer is currently analyzed Note In the Spectrum application this functionality is referred to as gating 1 In the measurement display take a closer look at window 3 magnitude of the cap ture buffer The green bar shows how far the current measurement has already proceede
77. The instrument is adjusted to the stored settings for the selected standard and a measurement is started immediately How to Perform VSA According to Digital Standards 4 Press the RUN SINGLE key to stop the continuous measurement mode and start a defined number of measurements The measured data is stored in the capture buffer and can be analyzed see chap ter 8 3 How to Analyze the Measured Data on page 221 To load predefined settings files 1 In the Meas menu select the Digital Standards softkey 2 Inthe file selection dialog box select the standard whose settings you want to load To change the path press the arrow icons at the right end of the Path field and select the required folder from the file system 3 Press the Load button The dialog box is closed and the instrument is adjusted to the stored settings for the selected standard To store settings as a standard file 1 Configure the measurement as required see chapter 8 2 How to Perform Cus tomized VSA Measurements on page 212 2 In the Meas menu select the Digital Standards softkey 3 In the File Name field enter the name of the standard for which you want to store settings To change the path press the arrow icons at the right end of the Path field and select the required folder from the file system To insert a new folder select the New Folder button and enter a name in the New Folder dialog box 4 Press the Save but
78. Usage Setting only INSTrument DELete lt ChannelName gt This command deletes a measurement channel If you delete the last measurement channel the default Spectrum channel is activa ted Parameters lt ChannelName gt String containing the name of the channel you want to delete A measurement channel must exist in order to be able delete it Example INST DEL Spectrum4 Deletes the channel with the name Spectrum4 Usage Event INSTrument LIST This command queries all active measurement channels This is useful in order to obtain the names of the existing measurement channels which are required in order to replace or delete the channels Return values lt ChannelType gt For each channel the command returns the channel type and lt ChannelName gt channel name see tables below Tip to change the channel name use the INSTrument REName command Example INST LIST Result for 3 measurement channels ADEM Analog Demod IQ IQ Analyzer IQ IQ Analyzer2 Usage Query only Activating Vector Signal Analysis Table 11 1 Available measurement channel types and default channel names in Signal and Spectrum Analyzer mode Application lt ChannelType gt Default Channel Name Parameter Spectrum SANALYZER Spectrum Analyzer IQ IQ Analyzer Analog Demodulation R amp S FPS K7 ADEM Analog Demod GSM R amp S FPS K10 GSM GSM Noise R
79. e Measurement Example 1 User defined Measurement of Continuous QPSK Signal 404 e Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital NO ANG EE 405 e Measurement Example 3 User Defined Pattern Search and Limit Check 409 Programming Examples 11 13 1 Measurement Example 1 User defined Measurement of Continu ous QPSK Signal The following example describes a scenario similar to the one for manual operation described in chapter 9 2 Measurement Example 1 Continuous QPSK Signal on page 228 Configuring the measurement RST Reset the instrument FREQ CENT 1GHz Set the center frequency DISP TRAC Y RLEV 4dBm Set the reference level INST CRE NEW DDEM MyVSA Create new measurement channel for vector signal analysis named MyVSA DEM FORM QPSK Set the modulation type DEM QPSK FORM NORM Set the modulation order DEM MAPP CAT DEM MAPP WCDMA Set the symbol mapping to WCDMA DEM SRAT 1 MHz Set the symbol rate DEM TFIL NAME RRC DEM TFIL ALPH 0 35 Select the RRC transmit filter D D D Query the available symbol mappings for QPSK modulation D D D D LAY ADD 1 RIGH EVEC Create new window to the right of I Q constellation window 1 with error vector as data type Result 5 CALC5 FORM MAGN Set result type for window 5 to magnitude EVM DISPl
80. eI oec ter te Dex 28 e Eye DiagraniReal I coton lent et EC tr o fe dec dede Cla 29 Frequency alo To Dii t 29 e Pregusncy IRelallVe e etr estes 31 e Frequency Error Absolute ener eren tenente tnnt eden hehe nt 32 Result Types in VSA e Frequency Eror cocer rer tet td e De a 33 e Frequency Response Group 34 e Frequency Response 22 2 2 0 2 20 50 1 35 Frequency Response 36 Impulse Response Magritude rero rente seat pea 37 e Impulse Response 38 e Impulse Response 1 38 e Magnitude deeb ER E EDEN inet 39 Magnitude Overview tt ter eR 40 e Magnitude Relative uieciecece iere cerne e Epp Pecunia ERR Enn nu ERR Rn 42 e 42 ERR 43 EE ER se 44 MEI cA DIE E PPP 45 ia nantes 46 e FRESUM SUI ey coc
81. lt gt lt gt ar a 345 lt gt lt gt 346 CALCulate n DELTamarker m MlNimum PEAK essent 345 CALCulate lt n gt DELTamarker lt m gt TRACe CAL Culatesn2z DEETamarkKerstis X oos eser rar eroe vete esee a conn ENRE EE EREE 343 CALCulate lt n gt DEL Tamarker lt m gt X ABSOlUtG itech te ed rper Tena 371 gt gt e rar err tte ro incre ete DER 371 CAL Culate lt n gt DEL Tamarkersin gt occuro orate EEEE 343 GALGulate n DELTamarker em STATe etpr rere tinere rti rrr tener erento 342 GALCulate n ELINsstartstop S TATe6 erre TEN rr i tero CALCulate lt n gt ELIN lt startstop gt VALue ej Mei idem ej emi T3 uei mc M lt gt 5 CALCulate lt n gt FSK DEViation REFerence RELativo nacer ett pete ete eene gn CALCulate lt n gt FSK DEViat
82. tion Range on page 241 Evaluating the Entire Result Range RR DER RAMUS 188 T 188 Evaluating the Entire Result Range If enabled the entire result range is evaluated If disabled you can define a specific part of the result range to be evaluated Remote command CALCulate lt n gt ELIN lt startstop gt STATe on page 328 Start Stop Defines the symbol in the result range at which evaluation is started and stopped The start and stop symbols themselves are included in the evaluation range Note Note that the start and stop values are defined with respect to the x axis includ ing an optional offset defined via the Symbol Number at Reference Start parameter Remote command CALCulate lt n gt ELIN lt startstop gt VALue on page 329 5 12 Adjusting Settings Automatically Some settings can be adjusted by the R amp S FPS automatically according to the current measurement settings In order to do so a measurement is performed The duration of this measurement can be defined automatically or manually To activate the automatic adjustment of a setting select the corresponding function in the AUTO SET menu or in the configuration dialog box for the setting where available Setting the Reference Level Automatically Auto _ 188 Resetting the Automatic Measurement Time Meastime Auto 189 Changing the Automati
83. 1 Select the measurement window 2 Press the AUTO key e 3 the Y Axis Auto Scale softkey Problem The trace of the measurement signal is visible in the measurement win dow the trace of the reference signal is not Solution e 1 Select the measurement window R amp S FPS K70 Optimizing and Troubleshooting the Measurement emm W M HMr SEE sy 2 Press the TRACE key 3 Press the Trace Config softkey 4 Select a second trace choose Clear Write as Trace Mode and toggle to Ref in the Evaluation column Trace Wizard Screen Trace Trace Mode Evaluation 7 Trace 3 Blank gt 4 Blank Trace 5 Blank E Trace 6 Blank V Preset Select All Traces Max Avg Min Cirwrite Min Problem The measurement window does not show average results Solution e 1 Select the measurement window 2 Press the TRACE key 3 Press the Trace Config softkey 4 Select a second trace and choose the preferred Trace Mode e g Max Hold or Average Spectrum VSA Ref Level 0 00 dBm Mod m el Att 20 0 dB Freq 1 0GHz ResLen TRG EXT Trace Trace Mode Evaluation 1 Cw 2 Avg Max Y rmi J ctear write Sie Zoen oam ees 7 2 pu Trace 4 2 1 f Y 1 P
84. 100 Hz to 50 MHz proportional up to maximum 40 MHz 50 MHz to 10 GHz 40 MHz R amp S FPS with activated option B160 I Q Bandwidth Extension sample rate 100 Hz 10 GHz maximum bandwidth 160 MHz Sample rate Maximum bandwidth 100 Hz to 200 MHz proportional up to maximum 160 MHz 200 MHz to 10 GHz 160 MHz 4 3 Restrictions The optional bandwidth extension R amp S FPS B160 can not be activated if any of the fol lowing conditions apply e R amp S FPS firmware versions previous to 1 20 e For center frequencies larger than 7 GHz e With any trigger except for an external trigger Symbol Mapping Mapping or symbol mapping means that symbol numbers are assigned to constellation points or transitions in the I Q plane e g PSK and QAM In the analyzer the mapping is required to decode the transmitted symbols from the sampled or frequency time data records The mappings for all standards used in the analyzer and for all employed modulation modes are described in the following Unless indicated otherwise symbol numbers are specified in hexadecimal form MSB at the left 4 3 1 Symbol Mapping Phase Shift Keying PSK With this type of modulation the information is represented by the absolute phase position of the received signal at the decision points All transitions in the I Q diagram are possible The complex constellation diagram is shown The symbol numbers are entered in the diagr
85. 2 203 Synchronization 244101 Coarse aa 183 Demodulatiotm ertt tree tenens 180 Demodulation process 90 FINE M 183 Known data 183 184 183 Remote 918 Symbol rror rate SER 184 Syntax Known data 423 T Trace Export 193 Data mode 193 Header information 193 Storage location 194 sd ee wax 192 Averaging 431 Capture Buffer remote 375 Cartesian Diagrams remote 2 376 Configuration 2 190 Configuring remote control 338 Equalizer remote Evaluation 192 Export eda tech don 194 EXPOMUMG er 194 207 dala verint ek 226 Measurement signal 192 Mode aes 91 Mode remote 22939 Polar Diagrams remote 376 Reference SIGMA roter ce 192 Result Summary 376 Retrieving data remote zn 9f 1 SELOCUING Re ETT 191 Settings remote control 33
86. 4 e 1 D 1 D 1 1 1 D D i D D i D D 1 D 1 1 n c e e ce c ce e eo e N N e co e i T T 1 T Y 1 gp gp apnyubeyy f Frequency in 25 H D8P SK Wide 4 4 4 20 D 1 T D 4 a 4 d 1 1 L 4 Li 4 4 e 1 1 L 4 LU LU 1 1 1 T 4 4 4 5 4 T LU 1 D 1 1 LU f LU N LU 1 D R 4 L 1 LI LU LU LU co See ee LU LU 1 D L LU ue 1 D D L T L F f p N 5 p 4 4 i 4 HL 1 c ce e N e 02 T T 1 ap fsymbol Frequency in Formulae 25 H CPM 4 4 20 gp 1 lt ee 1 1 4 4
87. 7 ANON ZH NSO 221001 2 08S 59 0 MSND lt 80 2 MSING UAS WS9 2051 59 0499 ANON ZH WSO 9227 90 Srl 0051 WSS 0 MSND 22228 022 MSING 159 ws Sea u16ue sang 19114 9je1 Budden 1895 ulayed 10 10 YOIeAS 19 5 Joquis pyepuejs pue 5 Jo 3517 L L Predefined Standards and Settings s ous e JO pJepuejs OU SJOYIP eSeuw pepiwoJd si Jo 425 991 x 2 71061 9 MSH 3503 7 2983 esingepiM 1ejue2 0051 Wvo9 edeug esind 8908 usu wy 5221 LLL V ma903 zHMSze WvOOSI v L 09 3903 asing 7961 VOS MOJJEN MSH 3503 T 2 edeus 0051 Wvo9 asind 8908 usu wv 5221 wened LLL V zHisze 3903 271081 YSH esind epi 7 3903 esingepiM _ 0081 Sd edeug esind 3909 usH s 52241 LL 3903 epmaoaa gt
88. A RENNES Tm 159 lg c 159 mum PEINE aaa User Manual 11 76 8516 02 06 158 Signal Capture NUR DP 160 WIG GST Ems 160 greci dB 160 V E 160 DropsOut TilTiQ 161 MOP so E A E 161 OGOM E 161 Capture Offset 161 Trigger Source Defines the trigger source If a trigger source other than Free Run is set TRG is displayed in the channel bar and the trigger source is indicated Remote command TRIGger SEQuence SOURce on page 306 Free Run Trigger Source No trigger source is considered Data acquisition is started manually or automatically and continues until stopped explicitely Remote command TRIG SOUR IMM see TRIGger SEQuence SOURce on page 306 External Trigger 1 2 Trigger Source Data acquisition starts when the TTL signal fed into the specified input connector meets or exceeds the specified trigger level See Trigger Level on page 160 Note The External Trigger 1 softkey automatically selects the trigger signal from the TRG IN connector For details see the Instrument Tour chapter in the R amp S FPS Getting Started manual External Trigger 1 Trigger signal from the TRG IN connector External Trigger 2 Trigger
89. Aa 311 SENSeJdDDEMod SEARcRh SYNC IQGC Ihreshold 21 1 iere 311 SENSe DDEMod SEARCH S NC MODE etuer 311 312 3 5 312 SENSe DDEMod SEARch PATTern CONFigure AUTO lt AutoConfigure gt This command sets the IQ correlation threshold to its default value Setting parameters lt AutoConfigure gt ON OFF 1 0 RST 1 Configuring VSA Manual operation See Q Correlation Threshold on page 167 SENSe DDEMod SEARch SYNC AUTO lt AutoPattSearch gt This command links the pattern search to the type of signal When a signal is marked as patterned pattern search is switched on automatically Setting parameters lt AutoPattSearch gt AUTO MANual RST AUTO Manual operation See Enabling Pattern Searches on page 167 SENSe DDEMod SEARch SYNC IQCThreshold lt CorrelationLev gt This command sets the IQ correlation threshold for pattern matching in percent A high level means stricter matching Setting parameters lt CorrelationLev gt numeric value Range 10 0 to 100 0 RST 90 0 Default unit PCT Manual operation See Q Correlation Threshold on page 167 SENSe DDEMod SEARch SYNC MODE lt MeasOnlyOnPatt gt This command sets t
90. Aborting ERR Q 161 162 ACIDE Coupling idee ice ta 143 149 Activating VSA remole ni rete cot n tein 269 Alignment Iesult range err eren re eene 175 AlphalBT 138 186 Amplitude Gotifig ratiOn oreet deiner aei eene Configuration remote Distortion effect Ws up Amplitude droop Compensation rrr ea rrr rene 178 Definition Formula Analysis Bandwidth definition oie 64 190 Analysis interval Configuration MSRA remote 354 entere reete Analysis WAG ertet Configuration MSRA remote Analyzing Measured data orm rernm rennes 221 APSK Modulation re nnns Symbol mapping ASCII Trace export cero m etri nnn ASK Modulation creer rre rens 135 Symbol MAPPING or rennes 85 Attenuation 149 AUO nre 149 Configuration remote iis iei 150 149 Option Protective remote Audio signals Output remote eic ee onte Auto level IAE Reference level trenes kic EC Auto settings Meastime Auto Meastime Manual
91. Any existing assignments to other standards are removed Remote command SENSe DDEMod SEARch SYNC DELete on page 313 Pattern details Pattern details for the currently focussed pattern are displayed at the upper right hand side of the dialog box You can refer to these details for example when you want to add a new pattern to the standard and want to make sure you have selected the cor rect one Pattern Search On If enabled the VSA application searches for the selected pattern This setting is identi cal to the setting in the Pattern Search dialog box see Enabling Pattern Searches on page 167 Remote command SENSe DDEMod SEARch SYNC STATe on page 312 Meas only if Pattern Symbols Correct If enabled measurement results are only displayed and are only averaged if a valid pattern has been found When measuring signals that contain a pattern and are aver aged over several measurements it is recommended that you enable this option so that erroneous measurements do not affect the result of averaging Remote command SENSe DDEMod SEARch SYNC MODE on page 311 5 7 4 Pattern Definition New patterns can be defined and then assigned to a standard Patterns are defined in the New Pattern dialog box which is displayed when you select the New button in the Advanced Pattern Settings dialog box Burst and Pattern Configuration Description Mod Order Symbols Format Binary Hex Decimal
92. BURSt TOLerance on page 310 Min Gap Length Burst Configuration Represents the minimum distance in symbols between adjacent bursts The default value is 1 symbol in order to make sure that the burst search finds bursts that are very close to each other However in case the capture buffer does not contain very close bursts it is recommended that you increase the value This makes the burst search faster and also more robust for highly distorted signals Note that this parameter only influences the robustness of the burst search It should not be used to explicitly exclude certain bursts from the measurement For example setting the minimum gap length to 100 symbols does not ensure that the burst search does not find bursts that have a very small gap Remote command SENSe DDEMod SEARCh BURSt GLENgth MINimum on page 309 5 7 2 Pattern Search The Pattern Search settings define when a pattern is detected in the evaluated sig nal A live preview of the capture buffer with the current settings is displayed in the preview area at the bottom of the dialog box The preview area is not editable directly The Pattern Search settings are displayed when you do one of the following e Select the Burst Pattern button from the Overview Select the Burst Pattern Search softkey from the main VSA menu Then switch to the Pattern Search tab R amp S FPS K70 Configuration Burst Search
93. Evaluation of results in the FSK result summary Frequency Error RMS 1 FREQ _ ERR T Peak max FREQ ERR n T Magnitude Error RMS 1 MAG_ERR a Tp Y Peak max MAG_ERR n T Formulae FSK Deviation Error A ERR rrr z A yeas x per B 1 per Estimated FSK deviation error Hz FSK Measurement Deviation A MEAS Aygas Estimated FSK deviation of the meas signal Hz FSK Reference Deviation A REF FSK reference deviation as entered by the user Hz Carrier Frequency Error fo j E The carrier frequency error of the measured signal Hz Carrier Frequency Drift _ 2 z T The drift in the carrier frequency of the measured signal Hz Sym d A 6 3 Statistical Evaluations for the Result Summary The statistical evaluations in the result summary are based on the measurement results that are displayed in the Current column Hence the index m here repre sents the current evaluation M is the total number of evaluations In single sweep mode M coresponds to the statistics count If the measurement values are represented in the logarithmic domain the linear values are averaged The result is then subsequently converted back into logarithmic domain The linear values are indicated by the subscript lin in chapter A 6 2 1 PSK QAM and MSK Modulation on page 428 Mathe
94. PEAK xe tht 198 Preamp 149 Ref Level 148 Ref Level 148 Refresh 163 RF Atten Auto wee 149 RF Atten Manual 149 Signal Capture 154 Signal Description 134 Single SWEGD intern erinnere 162 Trace 1 2 9 4 192 Trace Config eene 190 Trigger Offset onere 160 Trigger Gate Config 157 Upper Level Hysteresis e 189 Window configuration 201 Specifics for ConfigulatiOti cire oerte ret tee 133 Spectrum Result type transformation 202 SR see Symbol rate rem tern 12 Standards see Digital standards 129 DUALS COUN nter trends 162 DISPIAY 12 Statistics e 430 in eaa 203 Result type transformation 202 Status registers Descrlpltiori acere b e eee eio p cane iat STAT QUES POW Status reporting system StdDev FORMULA 430 Storage location Secure user teniente re eere 130 iur 130 Suffixes COMMON 269 Sweep B Configuration remote 2s C
95. R amp S FPS K70 Measurement Examples Mag CapBuf Stop 10000 sym Fig 9 7 Preview of capture buffer 9 3 3 Navigating Through the Capture Buffer This example describes how to navigate through the capture buffer for a continuous signal This navigation feature is especially important for bursted signals Therefore we provide a further navigation example for the GSM EDGE signal 1 In order to see more details in the capture buffer close window 4 a Press the Display Config softkey or the Display Configuration button in the Overview b Select the Delete icon for window 4 Close the SmartGrid mode by selecting the Close icon at the top right corner of the toolbar 2 Press the RUN SINGLE key 3 In the EVM vs Time display window 1 add a maximum hold trace by pressing the TRACE key and then selecting the Trace Config softkey see chapter 9 2 5 Averaging Several Evaluations on page 234 4 Re evaluate the whole capture buffer by pressing the SWEEP key and then the Refresh softkey 5 Use the Select Result Rng softkey to navigate through your capture buffer Thus you can determine which peak was caused by which burst aeaea User Manual 1176 8516 02 06 239 R amp S FPS K70 Measurement Examples spectrum VSA Ref Level 25 00 dBm Std EDGE 6PSK SR 270 833 kHz Att 10 dB Freq 10 GHz ResLen 148 SGL Stat Count BURST PATTERN A EVM 1 Crw 2 B Result Summary Continu
96. Range 0 to 31990 RST 1 Default unit SYM Manual operation See Run In on page 140 SENSe DDEMod SEARch SYNC CATalog Patterns This command reads the names of all patterns stored on the hard disk The file names are returned as a comma separated list of strings one for each file name without the file extension Setting parameters Patterns CURRent ALL CURRent Only patterns that belong to the current standard ALL All patterns RST ALL Example DDEM SEAR SYNC CAT CURR Result GSM ABO GSM AB1 GSM AB2 GSM TSC1 Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 SENSe DDEMod SIGNal PATTern lt PatternedSignal gt This command specifies whether the signal contains a pattern or not Setting parameters PatternedSignal 110 RST 0 Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See on page 140 SENSe DDEMod SIGNal VALue lt SignalType gt This command specifies whether the signal is bursted or continuous 11 5 2 Configuring VSA Setting parameters lt SignalType gt CONTinuous BURSted RST CONTinuous Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Signal Type on page 139 SENSe DDEMod STA
97. Return values lt WindowName gt Windowlndex Example Usage string Name of the window In the default state the name of the window is its index numeric value Index of the window LAY CAT Result 2 2 1 1 Two windows are displayed named 2 at the top or left and 1 at the bottom or right Query only Configuring the Result Display LAYout IDENtify WINDow lt WindowName gt This command queries the index of a particular display window in the active measure ment channel Note to query the name of a particular window use the LAYout WINDow lt n gt IDENtify query Query parameters lt WindowName gt String containing the name of a window Return values Windowlndex Index number of the window Usage Query only LAYout REMove WINDow lt WindowName gt This command removes a window from the display in the active measurement channel Parameters lt WindowName gt String containing the name of the window In the default state the name of the window is its index Usage Event LAYout REPLace WINDow lt WindowName gt lt WindowType gt This command replaces the window type for example from Diagram to Result Sum mary of an already existing window in the active measurement channel while keeping its position index and window name To add a new window use the LAYout ADD WINDow command Parameters lt WindowName gt String containing the name of the
98. Table 1 4 Typical combinations of Tx and Meas filters Transmit filter Measurement filter Remarks analyzer RC raised cosine filter combination without intersymbol interfer ence ISI RRC root raised cosine RRC filter combination without ISI GMSK filter combination with low ISI Linearized GMSK EDGE NSR standard specific filter filter combination with ISI Gauss filter combination with low ISI Rectangular filter combination without ISI Half Sine filter combination without ISI CDMA2000 1X FORWARD Low ISI Meas Filter filter combination without ISI CDMA2000 1X REVERSE Low ISI Meas Filter filter combination without ISI APCO25 Rectangular filter combination without ISI APCO25 H CPM Rectangular filter combination without ISI APCO25 H DQPSK Low ISI Meas Filter filter combination without ISI APCO25 H D8PSK Narrow Low ISI Meas Filter filter combination without ISI APCO25 H D8PSK Wide Low ISI Meas Filter filter combination without ISI EDGE Narrow Pulse Shape EDGE HSR Narrow standard specific filter filter combination with Pulse ISI EDGE Wide Pulse Shape EDGE HSR Wide Pulse standard specific filter filter combination with ISI User Low ISI Meas Filter filter combination with low ISI A 4 ASCII File Export Format for VSA Data The data of the file header consist of three columns each separated by a semicolon parameter name numeric value basic un
99. The evidence of a deviation error in the instantaneous fre quency of an FSK signal is demonstrated in figure 4 62 Measurement Ranges Instantaneous Frequency GMSK Modulation Meas Deviation Frequency Ref Deviation Freq Ref Meas 70 5 10 15 20 25 30 Time Symbols Fig 4 62 The reference and measured instantaneous frequency of a GMSK signal with reference deviation error 4 6 Measurement Ranges The application contains three measurement ranges that need to be set by the user Capture Buffer Length The length of the capture buffer specifies how many data points are captured dur ing a single measurement For example if you want to measure a bursted signal it is recommended that you make the capture length long enough to ensure that in each capture buffer at least one entire burst is included The maximum capture buffer length is 50 Msymbols for a sample rate of 4 or 200 million samples Result Range The result range defines the symbols from the capture buffer that are to be demodulated and analyzed together For example bursted signals have intervals between the bursts that are not of interest when analyzing peaks or overshoots Thus the result range usually coin cides with the range of the capture buffer in which the burst is located The maximum result range length is 64 000 symbols for a sample rate of 4 or 256 000 samples 4 6 1 Measurement Ranges Eva
100. WINDow lt n gt TRACe lt t gt Y SCALe PDIVision on page 299 X Axis Scaling For statistics a histogram is displayed For these diagrams the x axis can be config ured as well Input Output and Frontend Settings Adjust Settings X Axis Scaling Adjusts the x axis scaling to the occurring statistical values Remote command CALCulate lt n gt STATistics SCALe AUTO ONCE on page 297 Default Settings X Axis Scaling Resets the x and y axis scalings to their preset values for the current measurement window Remote command CALCulate lt n gt STATistics PRESet on 296 Quantize X Axis Scaling Defines the number of bars to be displayed in the graph i e the granularity of classifi cations Remote command CALCulate lt n gt STATistics SCALe X BCOunt on page 297 X Axis Reference Value X Axis Scaling Defines a reference value on the x axis in the current unit Remote command DISPlay WINDow lt n gt TRACe lt t gt X SCALe RVALue on page 299 X Axis Reference Position X Axis Scaling Defines the position of the X Axis Reference Value on the x axis The position is defined as a percentage value where 0 refers to the beginning left side 100 96 refers to the end right side of the diagram The x axis is adapted so that the reference value is displayed at the reference position Remote command DISPlay WINDow lt n gt TRACe lt t gt X SCALe RPOSition on 299 Range per
101. because it can be used to explicitely exclude symbols from influencing the synchronization Useful length The burst excluding its Run In Out areas is sometimes referrred to as the useful part The minimum length of the useful part Min Length Run In Run Out must be 210 Remote commands A remote command is provided to determine the position of the current result range within the capture buffer SENSe DDEMod SEARch MBURst STARt 2 on page 374 Evaluation Range In some scenarios the result range contains symbols that are not supposed to be con sidered for the EVM or other calculated parameters that are displayed in the Result Summary R amp S FPS K70 Measurement Basics For example while you may want to display the ramps of a burst and thus include them in the result range they do not contribute to the error vectors or power levels Thus you would not include them in the evaluation range See also chapter 9 3 5 Setting the Evaluation Range on page 241 The evaluation range is always equal to or smaller than the result range and defines The range over which traces that do not have a time axis are displayed e g polar diagrams Therange over which the following parameters are calculated for the Result Sum mary EVM MER Phase Error Magnitude Error Power Evaluation range display In all displays over time except for capture buffer displays the evaluation range is indi cated by red li
102. depend ing on the modulation type Modulation Est Points PSK QAM 1 Offset QPSK 2 FSK MSK Capture Oversampling For manual mode the following settings are available 1 the estimation algorithm takes only the symbol time instants into account 2 two points symbol instant are used required for Offset QPSK Demodulation Settings Capture Oversampling the number of samples per symbol defined in the signal capture set tings is used see Sample Rate on page 156 i e all sample time instants are weighted equally Remote command SENSe DDEMod EPRate AUTO on page 319 SENSe DDEMod EPRate VALue on page 320 Coarse Synchronization It is not only possible to check whether the pattern is part of the signal but also to use the pattern for synchronization in order to obtain the correct reference signal For details on synchronization see chapter 4 4 Overview of the Demodulation Proc ess on page 88 If Auto mode is selected the detected data is used In manual mode you can select one of the following settings Data Default the detected data is used for synchronization i e unknown symbols Use this setting if no pattern is available or if the pattern is short or does not have suitable synchronization properties e g a pattern that consists of only one repeated symbol Pattern Known symbols from a defined pattern are used for synchronization Depen
103. enin eee 273 11 5 Configuring 5 2 22 275 11 6 Performing a Measurement eese nennen nnn nennen nnne nn 332 11 7 uc p 338 11 8 Configuring the Result Display essent 357 11 9 Retrieving 5 1 5 Ene 370 11 10 Importing and Exporting Data and Results ecce 390 11 11 Status Reporting 2 391 11 12 Commands for 402 11 13 Programming Examples essen nennen enne nnne nennen nannten 403 lo oet 411 Abbreviations intime ANEA Sansa 411 2 Predefined Standards and Settings eese 412 Predefined Measurement and Tx 1 1 419 A 4 ASCII File Export Format for VSA 2 422 11 421 A 5 Known Data File
104. not detected reduce the threshold if false bursts are detected increase the threshold 12 Optionally enable the Meas only if pattern symbols correct option In this case measurement results are only displayed if a valid pattern has been detected 13 Close the dialog box The selected pattern is used for a pattern search in the next measurement 8 2 2 1 How Assign Patterns to a Standard Only patterns that are assigned to the currently selected VSA standard are available for the pattern search To add a predefined pattern to a standard 1 In the Overview select Signal Description and switch to the Signal Structure tab How to Perform Customized Measurements 2 Select Pattern Config to display the Advanced Pattern Settings dialog box 3 In the list of All Patterns select the required pattern If the required pattern is not displayed see To change the display for the list of patterns on page 217 4 Select Add to Standard The selected pattern is inserted in the list of Standard Patterns 5 Select the pattern to be used for the pattern search from the list of Standard Pat terns To remove a predefined pattern from a standard 1 In the Overview select Signal Description and switch to the Signal Structure tab 2 Select Pattern Config to display the Advanced Pattern Settings dialog box 3 Select the pattern from the list of Standard Patterns 4 Select Remove from
105. see chapter 5 1 Default Settings for Vector Signal Analysis on page 128 After initial setup the parameters for the measurement channel are stored upon exiting and restored upon re entering the channel Thus you can switch between applications quickly and easily When you activate a measurement channel for the VSA application a measure ment for the input signal is started automatically with the default configuration The VSA menu is displayed and provides access to the most important configuration functions Automatic refresh of preview and visualization in dialog boxes after configura tion changes The R amp S FPS supports you in finding the correct measurement settings quickly and easily after each change in settings in dialog boxes the preview and visualization areas are updated immediately and automatically to reflect the changes Thus you can see if the setting is appropriate or not before accepting the changes Importing and Exporting I Q Data The I Q data to be evaluated VSA not only be measured by the VSA application itself it can also be imported to the application provided it has the correct format Fur thermore the evaluated data from the VSA application can be exported for further analysis in external applications The import and export functions are available in the Save Recall menu which is dis played when you select the LI Save or Open icon in the toolbar For details on
106. short bursts or signal mix This user manual contains a description of the functionality that the application pro vides including remote control operation Functions that are not discussed in this manual are the same as in the Spectrum appli cation and are described in the R amp S FPS User Manual The latest version is available for download at the product homepage http www2 rohde schwarz com product F PS html Installation You can find detailed installation instructions in the R amp S FPS Getting Started manual or in the Release Notes 2 1 Starting the VSA Application The application adds a new application to the R amp S FPS D Manual operation via an external monitor and mouse Although the R amp S FPS does not have a built in display it is possible to operate it inter actively in manual mode using a graphical user interface with an external monitor and a mouse connected It is recommended that you use the manual mode initially to get familiar with the instru ment and its functions before using it in pure remote mode Thus this document describes in detail how to operate the instrument manually using an external monitor and mouse The remote commands are described in the second part of the document For details on manual operation see the R amp S FPS Getting Started manual 2 2 Understanding the Display Information To activate the VSA application 1 Select the MODE key A dialog box opens that cont
107. stored as a user defined standard RST Reset the instrument FREQ CENT 1GHz Set the center frequency DISP TRAC Y RLEV 4dBm Set the reference level INST CRE NEW DDEM VSA Create new measurement channel for vector signal analysis named VSA DDEM SEAR SYNC NAME EDGE TSC CUST Create new pattern DDEM SEAR SYNC NST 4 DDEM SEAR SYNC DATA 00030001000000000003000200020001000300010001 DDEM SEAR SYNC COMM Customized pattern DDEM SEAR SYNC TEXT Special edge normal Burst DDEM SEAR SYNC NAME EDGE TSC CUST D Store customized pattern DEM SEAR SYNC PATT ADD EDGE TSC CUST Add new pattern to current standard ecu Configuring the expected input signal DEM FORM QPSK Set the modulation type DEM QPSK FORM NORM Set the modulation order DEM MAPP CAT Query the available symbol mappings for QPSK modulation DEM MAPP WCDMA Set the symbol mapping to WCDMA DEM SRAT 1 MHz Set the symbol rate e gt M Bo Se duy CO SEA SS U DEM SIGN BURS Define input signal as burst signal DEM SIGN PATT ON U Programming Examples Enable pattern search DEM SEAR SYNC CAT CURR Query the names of all defined patterns assigned to the current standard DEM SEAR SYNC SEL EDGE TSC CUST DEM STAN SYNC OFFS 10 Ignore the first 10 symbols of the signal before comparing pattern DEM STAN SYNC OFFS STAT ON D D Select a pattern D D D DEM
108. 0 01 0 0 0 01 9 00 Quadrature Error 0 01 0 0 0 01 2 0 Amplitude Droop 0 000 000 0 000 000 0 000 000 2 000 000 Power 24 21 24 24 21 6 00 1EVM 349 sym 451 sym Fig 3 20 Example for result summary with current EVM peak value marked If you want to compare the trace values to the results of the Result Summary make sure to match the displayed points per symbol of the trace and of the Result Summary Refer to Display Points Sym on page 203 for details Mean value In the Mean column the linear mean of the values that are in the Current column is displayed Note that if the values are a logarithmic representation e g the I Q Off set the linear values are averaged Peak value In the Peak column the maximum value that occurred during several evaluations is displayed Note that when the value can be positive and negative e g the phase error the maximum absolute value maintaining its sign is displayed The peak value of Rho is handled differently since its minimum value represents the worst case In that case the minimum value is displayed Standard Deviation The value for the standard deviation is calculated on the linear values and then conver ted to the displayed unit 95 percentile The 95 percentile value is based on the distribution of the current values Since the phase error and the magnitude error can usually be assumed to be distributed around zero the 95 Percentile for these values is calcu
109. 06 54 Common Parameters in VSA Parameter Description SCPI Parameter Magnitude Error The average RMS and peak magnitude error in The MERRor RMS Peak magnitude error is the difference of the measured magnitude to the magnitude of the reference signal The magnitude error is normalized to the mean magnitude of the reference signal Carrier Frequency The mean carrier frequency offset in Hz CFERror Error Symbol Rate Error Difference between the currently measured symbol rate and SRER the defined symbol rate in ppm Only for PSK QAM or UserQAM modulation and only if compensation for SRE is activated see chapter 5 9 1 Demodulation Compensation on page 176 Rho RHO Offset Offset in the original input OOFFset I Q Imbalance Not for BPSK IQIMbalance Gain Imbalance Not for BPSK GIMBalance Quadrature Error Not for BPSK QERRor Amplitude Droop The decrease of the signal power over time in the transmitter ADRoop Power The power of the measured signal MPOWer Table 3 5 Parameters for FSK modulation only Parameter Description SCPI parameter Frequency Error RMS The average RMS and peak frequency error in 96 The FSK DERRor Peak frequency error is thedifference of the measured fre quency and the reference frequency The frequency error is normalized to the estimated FSK deviation FSK Deviation Error The deviation error of FSK modulated signals in Hz The FDERro
110. 1 Parameters lt ChannelType gt VSA VSA R amp S FPS K70 SYSTem PRESet CHANnel EXECute This command restores the default instrument settings in the current channel Use INST SEL to select the channel Example INST Spectrum2 Selects the channel for Spectrum2 SYST PRES CHAN EXEC Restores the factory default settings to the Spectrum2 channel Usage Event Manual operation See Preset Channel on page 133 11 4 Digital Standards Various predefined settings files for common digital standards are provided for use with the VSA application In addition you can create your own settings files for user specific measurements Manual configuration of digital standards is described in chapter 5 2 Configuration According to Digital Standards on page 129 SENS amp TDDEMod FACTory VAL 21r taret cerea euet re eot recto 273 SENSe DDEMod PRESet S TANdard cette 274 5 2 274 5 274 5 275 SENSe DDEMod S TANGard 2 sea err eaaet o eo essa aae ace 275 SENSe DDEMod FACTory VALue Fac
111. 2 2 198 Next minimum 198 Next peak 198 198 POSINOMING 198 Querying position remote Retrieving values remote wot Search settings 196 Settings remote 940 State cese 195 gone 196 POT E 195 Matched filter one rci iere tas ethics 58 Max Peak ire ntes 198 Maximizing Windows remote eec tici te atit eec 358 Mean onim e 430 Meas amp Ref Data source Result types MEAS filter Meas only if burst was found T Measurement bandwidth sse Measurement channel Creating remote sese 270 Deleting remote m Duplicating remote eee 270 Querying remote Renaming remote Replacing remote 270 Measurement example Burst GSM EDGE Signals 235 Continuous QPSK i e 228 Measurement examples Burst GSM EDGE signal remote 405 Continuous QPSK signal remote 404 Measurement filter 25 150 ANABI 3 score erat rtt ae pte 186
112. 347 lt gt lt gt 5 348 lt gt lt gt 51 5 348 CALCulate lt n gt DELTamarker lt m gt MAXimum APEak This command positions the active marker or deltamarker on the largest absolute peak value maximum or minimum of the selected trace Usage Event CALCulate lt n gt DELTamarker lt m gt MAXimum LEFT This command moves a delta marker to the next higher value The search includes only measurement values to the left of the current marker posi tion Usage Event Analysis CALCulate lt n gt DELTamarker lt m gt MAXimum NEXT This command moves a marker to the next higher value Usage Event Manual operation See Search Next Peak on page 198 CALCulate lt n gt DELTamarker lt m gt MAXimum PEAK This command moves a delta marker to the highest level If the marker is not yet active the command first activates the marker Usage Event Manual operation See Peak Search on page 198 CALCulate lt n gt DELTamarker lt m gt MAXimum RIGHt This command moves a delta marker to the next higher value The search includes only measurement values to the right of the current marker posi tion Usage Event CALCulate lt n gt DELTamarker lt m gt MINimum LEFT This command moves a delta marker to the next higher minimum value The search includes only m
113. 4 59 Frequency Modulator Fig 4 59 Reference complex baseband FSK signal generation Reference Deviation The transmitted symbols 5 are assumed to be chosen from a finite and real valued constellation of M values 6 Gv The maximum absolute constellation point is denoted by yax The maximum phase contribution of a data symbol is given by max 72 zh Gay 50 The reference deviation of the FSK signal is defined as _ max _1 f AREF DNE Sgh smx 04 In the VSA application the frequency pulse filter is normalized such that 8 at Signal Model Estimation and Modulation Errors The constellation for M FSK is assumed to be 37 3 M 1 which implies Smax M 1 The expression for the reference deviation in terms of the modulation index is therefore given by 1 A pep 0 1 fs The above formula provides the necessary calculation for measurement of an FSK sig nal with known symbol rate and modulation index Calculation examples The GSM standard describes the transmission of binary data using MSK i e 2FSK modulation with a modulation index of h 1 2 at a symbol rate of 270 8333 KHz reference deviation is therefore given by Agnus E 8 2 1 270 8333 kHz 67 7083 kHz The APCO Project 25 standard phase 2 defines a H CPM signal i e 4AFSK with a modulation index of h 1 3 and a symbol rate of 6 KHz The reference deviation is 4 1 6 2
114. 56 Its flat usable bandwidth no considerable amplitude or phase distortion depends on the used sample rate which depends on the defined Symbol Rate see Symbol Rate on page 137 the defined Sample Rate parameter see Sample Rate on page 156 For details on the maximum usable bandwidth see chapter 4 2 Sample Rate Symbol Rate and Bandwidth on page 63 played in the Signal Capture dialog see chapter 5 6 1 Data Acquisition 0 The sample rate and the usable bandwidth achieved for the current settings is dis on page 155 R amp S FPS K70 Measurement Basics 4 1 2 Demodulation Bandwidth Measurement Bandwidth Some modulation systems do not use a receive filter In these cases special care should be taken that no interference or adjacent channels occur within the demodula tion bandwidth The Sample rate parameter should be set to a low value see Sam ple Rate on page 156 Typical communication systems demand special receive or measurement filters e g root raised cosine receive filter or EDGE measurement filter If no such filtering is performed care should be taken that neither interfering signals nor adjacent channels fall within the demodulation bandwidth 41 3 Modulation and Demodulation Filters Sample points are required for demodulation in the analyzer where only information of the current symbol and none of neighbouring symbols is present symbol points These points ar
115. ADD 1 BEL TCAP see LAYout ADD WINDow on page 359 Measurement amp Reference Signal The measurement signal or the ideal reference signal or both The default result type is Magnitude Relative The following result types are available chapter 3 2 21 Magnitude Absolute on page 39 chapter 3 2 23 Magnitude Relative on page 42 chapter 3 2 26 Phase Wrap on page 44 chapter 3 2 27 Phase Unwrap on page 45 chapter 3 2 11 Frequency Absolute on page 29 chapter 3 2 12 Frequency Relative on page 31 chapter 3 2 28 I Q on page 46 User Manual 1176 8516 02 06 15 Evaluation Data Sources in VSA chapter 3 2 10 Eye Diagram Real 1 on page 29 chapter 3 2 9 Eye Diagram Imag Q on page 28 chapter 3 2 8 Eye Diagram Frequency on page 27 chapter 3 2 5 Constellation on page 24 chapter 3 2 32 Vector on page 53 chapter 3 2 4 Constellation Frequency on page 23 chapter 3 2 31 Vector Frequency on page 52 Remote command LAY ADD 1 BEL REF see LAYout ADD WINDow on page 359 Symbols The detected symbols i e the detected bits displayed in a table The default result type is a hexadecimal symbol table Other formats for the symbol table are available but no other result types see chap ter 3 2 30 Symbol Table on page 51 Remote command LAY ADD 1 BEL SYMB see LAYout ADD WINDow on page 359 Error Vector The m
116. BEL CBUF to define the required source type see LAYout ADD WINDow page 359 CALC FORM MAGN to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 1 Capture Buffer Results on page 375 Magnitude Overview Absolute Magnitude of the source signal in the entire capture buffer the actual signal amplitude is displayed Mag 8 with t2n and Tp the duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 User Manual 1176 8516 02 06 40 R amp S FPS K70 Measurements and Result Displays E Note that for very large numbers of samples gt 25 000 the samples are mapped to 25 000 trace points using an autopeak detector for display Thus this result display is not suitable to detect transient effects or analyze individual symbols closely For these purposes use the Magnitude Absolute result display instead The Magnitude Overview Absolute is only available for the source type e Capture Buffer 1 Mag Overview CaptureBuffer 220000 sym Fig 3 13 Result display Magnitude Overview Absolute for capture buffer data Restrictions Note the following restrictions that apply to this result display e Only one trace is available Only the trace modes Clear Write and Vi
117. Configuring an Analysis Interval and Line MSRA mode only In MSRA operating mode only the MSRA Master actually captures data the MSRA applications define an extract of the captured data for analysis referred to as the analysis interval The analysis line is a common time marker for all MSRA applica tions For the VSA application the commands to define tha analysis interval are the same as those used to define the actual data acquisition see chapter 11 5 3 Signal Capture on page 301 Be sure to select the correct measurement channel before executing these commands Useful commands related to MSRA mode described elsewhere INITiate lt n gt REFResh page 335 INITiate lt n gt SEQuencer REFResh ALL on page 335 Remote commands exclusive to MSRA applications The following commands are only available for MSRA application channels lt gt 5 5 354 lt gt aiaa iiaii 355 gt 5 lt gt 2 355 5 355 CALCulate lt n gt MSRA ALINe SHOW This command defines whether or not the analysis line is displayed in all time based windows in all MSRA applications and the MSRA Master lt n gt is irrelevant Note even if the analysis line display is off the indi
118. Custom Digital Modulation A Press the FREQ key and enter 1 GHz Press the LEVEL key and enter 0 dBm Press the DIAGRAM key Select the Baseband A block Select Custom Digital Mod In the General tab define the following settings Power Ramp Control Off Cosine 1 00sym Fig 9 1 R amp S SMW200A Custom Digital Modulation Dialog a Toggle the State to On b Enter the Symbol Rate 1 MHz Set Coding to Off 8 In the Modulation tab select Modulation Type PSK gt QPSK 9 In the Filter tab select the Filter Root Cosine Measurement Example 1 Continuous QPSK Signal 10 Press the RF ON OFF key to switch the RF transmission on 9 2 2 Analyzer Settings This section helps you get your first valid measurement It starts with step by step instructions and continues with a more detailed description of further functionality Frequency 1GHz Ref Level 4 dBm Modulation QPSK Symbol Rate 1 MHz Tx Filter Root Raised Cosine with Alpha BT 0 35 To define the settings on the R amp S FPS 1 Press the PRESET to start from a defined state 2 Press the FREQ key and enter 1 GHz 3 Press the AMPT key and enter 4 dBm as the reference level This corresponds approximately to the peak envelope power of the signal 4 Start the VSA application by pressing the MODE key and then selecting VSA 5 Select the Overview softkey to display the Over
119. DATA on page 313 Symbol format Symbols Defines the format in which each symbol is defined hexadecimal decimal or binary Adding symbols Symbols Adds a new symbol in the symbol table to the left of the currently selected symbol Removing symbols Symbols Removes the currently selected symbol in the symbol table Comment Optional comment for the pattern displayed in the pattern details kept for compatibility with FSQ Remote command SENSe DDEMod SEARch SYNC COMMent on page 312 5 8 Result Range Configuration The result range determines which part of the capture buffer burst or pattern is dis played For more information see chapter 4 6 Measurement Ranges on page 116 A visualization of the result display with the current settings is displayed in the visuali zation area at the bottom of the dialog box The Result Range settings are displayed when you do one of the following e Select the Cut Result Ranges button from the Overview e Select the Range Settings softkey from the main VSA menu Result Range Configuration Result Range Evaluation Range Length Result Length 148 sym 546 462 ps Result Range Alignment Reference m Capture Burst Pattern Waveform Alignment Left o Center Right Offset sym Visualization 58 0sym 26 riu E 174 iio M M H 174 alo DAS
120. Division X Axis Scaling Defines the value range to be displayed per division on the x axis Since the display consists of 10 divisions by default the displayed range is Range 10 lt Range per Division gt Note If fewer divisions are displayed e g because the window is reduced in width the range per division is increased in order to display the same result range in the smaller window In this case the per division value does not correspond to the actual display Remote command DISPlay WINDow lt n gt TRACe lt t gt X SCALe PDIVision on page 299 5 5 4 3 Units You can configure the units for both axes of the diagrams The unit settings are displayed when you do one of the following e Select Input Frontend from the Overview and then switch to the Unit tab Signal Capture Select the AMPT key and then the Unit Config softkey TUUM 94 57 57 Res Len Amplitude YScale Unit Y Axis Unit 1 MagAbs Meas amp Ref di e Note that unit settings are window specific as opposed to the amplitude settings 5 6 PEE TS TETTE TORRE 154 BECAS SIE m UU 154 X Axis Unit Defines the unit of the x axis in the current result diagram Remote command CALCulate lt n gt X UNIT TIME on page 298 Y Axis Unit Defines the unit of the y axis in the current result diagram Remote command DISPlay WINDow
121. Failed The result range alignment is not possible for the patricular capture buffer The result range needs data that has not been captured trun VSA Ref Level 10 00 dim Att 1008 Freq 1 AEVM Length Result Range Alignment Result Range Alignment and Evaluation Range Reference Capture Burst Alignment Left Center Offset Symbol Burst Start 0 sym 1 a Start 126 sym Visualization Mag CapBuf EI D CB 4 4 T WI Config Start 0 sym Stop 500 sym Display 11 01 2010 115707 Fig 10 8 Example for failed alignment In this windowshot the alignment of the long result range to the burst center is not pos sible because there are not enough samples in the capture buffer before the burst starts In this scenario the trigger settings should be changed such that the burst is in the middle of the capture buffer Solution Change the trigger settings and or enlarge the capture length For more information see e chapter 5 6 Signal Capture on page 154 User Manual 1176 8516 02 06 251 R amp S9FPS K70 Optimizing and Troubleshooting the Measurement Message Pattern Search On But No Pattern Selected Spectrum VSA Modulation amp Signal Description Ref Level 4 00 Att 16 dB Modulation Signal Description SGL BURST PATTERN Signal Type A EVM Continuous Si
122. I Q data must exceed to cause a trigger event Note that any RF attenuation or preamplification is considered when the trigger level is analyzed Configuring VSA Parameters lt TriggerLevel gt Range 130 dBm to 30 dBm RST 20 dBm Example TRIG LEV IQP 30DBM Manual operation See Trigger Level on page 160 TRIGger SEQuence SLOPe lt Type gt For all trigger sources except time you can define whether triggering occurs when the signal rises to the trigger level or falls down to it Parameters lt Type gt POSitive NEGative POSitive Triggers when the signal rises to the trigger level rising edge NEGative Triggers when the signal drops to the trigger level falling edge RST POSitive Example TRIG SLOP NEG Manual operation See Slope on page 161 TRIGger SEQuence SOURce Source This command selects the trigger source Note on external triggers If a measurement is configured to wait for an external trigger signal in a remote control program remote control is blocked until the trigger is received and the program can continue Make sure this situation is avoided in your remote control programs Parameters Source IMMediate Free Run EXTernal Trigger signal from the TRIGGER IN connector EXT2 Trigger signal from the TRIGGER AUX connector RFPower First intermediate frequency IFPower Second intermediate frequency IQPower Magnitude of sampled data For applications that proc
123. IFPower on page 305 TRIGger SEQuence LEVel IQPower on page 305 TRIGger SEQuence LEVel EXTernal port on page 305 Trigger Offset Defines the time offset between the trigger event and the start of the measurement The time may be entered in s or in symbols offset 0 Start of the measurement is delayed offset 0 Measurement starts earlier pre trigger Only possible for zero span e g Analyzer application and gated trigger switched off Maximum allowed range limited by the measurement time pretrigger max measurement time Remote command TRIGger SEQuence HOLDoff TIME on page 304 Hysteresis Defines the distance in dB to the trigger level that the trigger source must exceed before a trigger event occurs Settting a hysteresis avoids unwanted trigger events caused by noise oscillation around the trigger level This setting is only available for IF Power trigger sources The range of the value is between 3 dB and 50 dB with a step width of 1 dB Remote command TRIGger SEQuence IFPower HYSTeresis on page 304 5 6 3 Signal Capture Drop Out Time Defines the time the input signal must stay below the trigger level before triggering again Remote command TRIGger SEQuence DTIMe on page 304 Slope For all trigger sources except time you can define whether triggering occurs when the signal rises to the trigger level or falls down to it Remote command TRIGger S
124. IQ Signal REF Signal ish 5 3 Correction 5 Parameters Signal 2 processing correction of t Analyzer estimated errors 55 22 Fig 4 2 Measurement filter in the block diagram MSK PSK QAM and UserQAM TX Filter Any QAM Any PSK bits VQ perd Map bits to TX Filter instantaneous frequency frequency pulse f k Magnitude 1 Fig 4 3 Modulator with Transmit filter in detail As the measurement filters of the VSA application have low pass characteristics they suppress high frequency distortion components in the Meas Ref Error signal The errors are weighted spectrally Thus turning off the measurement filter can have an influence on the numeric and graphical error values However the measurement filter should be switched off if non linear distortions have to be measured they usually pro duce high frequency components Filters and Bandwidths During Signal Processing Predefined measurement filters The most frequently required measurement filters are provided by the VSA application see chapter A 3 2 Measurement Filters on page 420 The frequency response of the available standard specific measurement filters is shown in chapter A 6 6 2 Measurement Filter on page 433 4 1 5 Customized Filters The analytical filter types RC raised cosine RRC root raised cosine and GAUS SIAN as well as the most important standard specific filter
125. IqTar xml file in web browser xslt RS IQ FileFormat fileFormatVersion 1 xsi noNamespaceSchemaLocation RsIqTar xsd xmlns xsi http www w3 0rg 2001 XMLSchema instance lt Name gt FSV K10 lt Name gt lt Comment gt Here is a comment lt Comment gt DateTime 2011 01 24T14 02 49 DateTime lt Samples gt 68751 lt Samples gt lt Clock unit Hz gt 6 5e 006 lt Clock gt lt Format gt complex lt Format gt Data File Format iq tar lt DataType gt float32 lt DataType gt lt ScalingFactor unit V gt 1 lt ScalingFactor gt lt NumberOfChannels gt 1 lt NumberOfChannels gt DataFilename xyz complex float32 DataFilename lt UserData gt lt UserDefinedElement gt Example lt UserDefinedElement gt lt UserData gt lt PreviewData gt lt PreviewData gt lt RS_IQ TAR FileFormat gt Element RS IQ TAR File Format Description The root element of the XML file It must contain the attribute ileFormatVersion that contains the number of the file format definition Currently fileFormatVersion 2 is used Name Optional describes the device or application that created the file Comment Optional contains text that further describes the contents of the file DateTime Contains the date and time of the creation of the file Its type is xs dateTime see RsIqTar xsd Samples Clock Contains the number of samples of the data For m
126. J 1 D 1 i ES D 1 D J 1 D i E 02 04 06 08 1 12 14 18 18 2 Frequency in Linearized GMSK mE lt Magnitude dB Frequency in f ymbol A 7 VQ Data File Format iq tar data is packed in a file with the extension iq tar ig tar file contains I Q data in binary format together with meta information that describes the nature and the source of data e g the sample rate The objective of the iq tar file format is to separate data from the meta information while still having both inside one file In addition the file format allows you to preview the data in a web browser and allows you to include user specific data The iq tar container packs several files into a single tar archive file Files in tar format be unpacked using standard archive tools see http en wikipedia org wiki Comparison of file archivers available for most operating systems The advantage of tar files is that the archived files inside the tar file are not changed not com pressed and thus it is possible to read the data directly within the archive without the need to unpack untar the tar file first Q Data File Format iq tar Sample iq tar files Some sample iq tar files are provided in the C R S Instr user vsa DemoSignals directory on the R amp S FPS Contained files An iq tar file must contain the f
127. MARKer lt m gt AOFF on page 341 Couple Windows If enabled markers in all diagrams with the same x axis time or symbols have cou pled x values except for capture buffer display i e if you move the marker in one dia gram it is moved in all coupled diagrams Remote command CALCulate lt n gt MARKer lt m gt LINK on page 341 Marker Search Settings Several functions are available to set the marker to a specific position very quickly and easily In order to determine the required marker position searches may be performed The search results can be influenced by special settings Markers These settings are available as softkeys in the Marker To menu or in the Search tab of the Marker dialog box To display this tab do one of the following Press the MKR key then select the Marker Config softkey Then select the hori zontal Search Settings tab nthe Overview select Analysis and switch to the vertical Marker Config tab Then select the horizontal Search Settings tab mE 2 Stat ON Markers Search Peak Search Real Imag Plot IMA Search Mode for Next Peak aa aaea ELI 197 Real Imag POL ertt e Ro EDEN E RN ERES 197 Search Limits Left BIO idiot recae tpe ert te Ede i 197 Search Mode for Next Peak Selects the search mode for the next peak search Left Determines the next maximu
128. Magnitude Absolute result display is suited better where one display point can be displayed for each sample taken Restrictions Trace modes that calculate results for several sweeps Average MinHold MaxHold are applied to the individual ranges in the capture buffer diagrams and thus may not provide useful results For the Magnitude Overview Absolute result display these trace modes are not available at all Furthermore only one trace can be configured in the Magnitude Overview Absolute result display 4 9 Known Data Files Dependencies and Restrictions Remote commands Remote commands are provided to determine the first and last values currently dis played in a particular window DISPlay WINDow lt n gt TRACe lt t gt X SCALe STARt on page 372 DISPlay WINDow lt n gt TRACe lt t gt X SCALe STOP on page 372 And to determine the position of the current result range within the capture buffer SENSe DDEMod SEARch MBURst 5 2 on page 374 Known Data Files Dependencies and Restrictions For various vector signal analysis functions the measured signal is compared to a defined ideal reference signal The more precise the reference signal the more precise the results become In the best case the possible data sequences within the signal to analyze are known in advance and can be used to compare the measured data to This is similar to defining a pattern for the entire result range Thu
129. PATTERN B Result Summary Phase Err RMS Carrier Freq Err Gain Imbalance Quadrature Err Amplitude Droop Start 76 sym C Mag CapBuf Spectrum VSA Ref Level 0 00 dBm Std EDGE 16QAM SR 270 833 kHz m tel Att 20 0 dB Freq 1 0 GHz ResLen SGL ResRange Count 0 BURST PATTERN Phase Err RMS Carrier Freq Err Gain Imbalance Quadrature Err Amplitude Droop Start 76 syn C Mag CapBuf 20 dBm 40 dBm Start 0 sym Fig 10 13 Solution Result Summary with correct evaluation range setting Make sure that the same samples are evaluated By default the EVM trace dis plays all sample instants e g if the sample rate is 4 the EVM trace shows 4 sam ples per symbol The Result Summary does not automatically evaluate all sample User Manual 1176 8516 02 06 259 R amp S FPS K70 Optimizing and Troubleshooting the Measurement instants E g fora PSK modulation by default only symbol instants contribute to the EVM result Spectrum VSA Ref Level 0 00 dBm Mod Offset QPSK SR 1 0 MHz m el Att 20 0 dB Freq 1 0GHz ResLen 100 iere SGL ResRange Count 0 Overview ei1ciw B Result Summary a NETT Hose ds Display 0 0 Config 0 0 0 power Start syrri Stop 103 sym C Const I Q Meas amp Ref 1M Clrw D Vector I Q Error 1 Restore Factory Settings Start 2 535 Stop 2 535 Start 0 254 Stop 0 254 Tri ta 12 03 2010 5 09 44 29 Question Why isn t the FSK Deviation Error i
130. POPMULAG Formulae FSI e reet 429 Result 47 Result type Display ettet teen ens 13 Transformation 202 Window configuration 2 2 2 202 Result types Bit rror rate 20 Capture buffer eterne 1S Channel Frequency Response Group Delay 22 Channel Frequency Response Magnitude 22 Constellation Frequency 23 Constellation eite tren 24 Constellation 25 eterne heran eres 17 iicet 216 Error Vector Magnitude EVM 26 Eye Diagram Frequency will Eye Diagram Imag Q 28 Eye Diagram Real 1 4 29 Frequency Absolute thereto 29 Frequency Error Absolute 32 Frequency Error Relative 4 93 Frequency Relative aot Frequency Response Group Delay Frequency Response Magnitude Frequency Response Phase is Impulse Response Magnitude Impulse Response Phase Impulse Response Real Imag m Magnitude Absol te itin motns Magnitude EFtOF Magnitude Overview Absolute
131. QAM If enabled compensation for various effects is taken into consideration during demodu lation Thus these distortions are not shown in the calculated error values Note Note that compensation for all the listed distortions can result in lower EVM val ues Offset default on User Manual 1176 8516 02 06 178 Demodulation Settings Imbalance Amplitude Droop default on Symbol Rate Error required to display the SRE in the Result Summary Channel default on Note that channel distortion can only be determined if the equalizer is on see State on page 179 Thus compensation can only be disabled if the equalizer is on By default channel compensation is enabled to improve accuracy of the error results If compensation is disabled the EVM is calculated from the original input signal with channel distortions For details on these effects see chapter 4 5 1 3 Modulation Errors on page 102 Remote command SENSe DDEMod NORMalize IQOFfset on page 325 SENSe DDEMod NORMalize IQIMbalance on page 325 SENSe DDEMod NORMalize ADRoop on page 324 SENSe DDEMod NORMalize SRERror on page 325 SENSe DDEMod NORMalize CHANnel on page 324 Compensate for FSK If enabled compensation for various effects is taken into consideration during demodu lation Thus these distortions are not shown in the calculated error values Carrier Frequency Drift e FSK Deviation Error e Symbol
132. Real Imag Plot on page 197 CALCulate lt n gt MARKer lt m gt X SLIMits LEFT lt SearchLimit gt This command defines the left limit of the marker search range for all markers in all windows lt m gt lt n gt are irrelevant Analysis If you perform a measurement in the time domain this command limits the range of the trace to be analyzed Parameters lt SearchLimit gt The value range depends on the frequency range or measure ment time The unit is Hz for frequency domain measurements and s for time domain measurements RST left diagram border lt Limit gt Range 1e9 to 1e9 RST 0 0 Example CALC MARK X SLIM ON Switches the search limit function on CALC MARK X SLIM LEFT 10MHz Sets the left limit of the search range to 10 MHz Manual operation See Search Limits Left Right on page 197 CALCulate lt n gt MARKer lt m gt X SLIMits RIGHT lt SearchLimit gt This command defines the right limit of the marker search range for a markers in all windows lt m gt lt n gt are irrelevant If you perform a measurement in the time domain this command limits the range of the trace to be analyzed Parameters lt Limit gt The value range depends on the frequency range or measure ment time The unit is Hz for frequency domain measurements and s for time domain measurements RST right diagram border lt Limit gt Range 1e9 to 1e9 RST 800 0 Example CALC MARK X SLIM ON Switch
133. SEAR SYNC STAT ON DDEM STAN SAVE C TEMP CustomizedBurstMeas INIT CONT OFF Select single sweep mode INIT WAI Initiate a new measurement and wait until it has finished Retrieving Results TRAC3 DATA 1 Query the trace results of the capture buffer display Results TRAC2 DATA 1 Query the results of the result summary Results Abbreviations A Annex The following sections are provided for reference purposes and include detailed infor mation such as formulae and abbreviations 411 e Predefined Standards and Settings eee 412 e Predefined Measurement and Tx Filters 419 e ASCII File Export Format for VSA e ttc 421 e Known Data File Syntax Description 423 425 VO Data File Format etre rette aede the ten 439 A 1 Abbreviations The following abbreviations are commonly used in the description of the R amp S FPS K70 option Abbreviation Meaning See section FSK Frequency Shift Keying Frequency Shift Keying FSK Modulation mode for which the information is encrypted in the fre quency ISI Inter symbol Interference ISI free demodulation Demodulation structure in which the signal is no longer influenced by adjacent symbols at the deci sion instants after signal adapted filtering Sy
134. SENSeJ DDEMod SEARCIhEBURSEALTQ a rt e ee e cree po Led da ek 309 SENSe DDEMod SEARch BURSt CONFigure AUTO eese nenne 309 SENSe DDEMod SEARCh BURSt GLENgth MINimum eese 309 Configuring VSA SENSe DDEMoc SEARchBURSEMODE 7 4 Pr ei etna ea nee eren os 309 SENSe DDEMod SEARGh BURSESTATe 22 entrate enacts n Roh eaa 310 8 5 5 1100011 310 SENSe DDEMod SEARch BURSt AUTO lt AutoBurstSearch gt This command links the burst search to the type of signal When a signal is marked as bursted burst search is switched on automatically Setting parameters lt AutoBurstSearch gt AUTO MANual RST AUTO Manual operation See Enabling Burst Searches on page 165 SENSe DDEMod SEARch BURSt CONFigure AUTO lt AutoConfigure gt This command sets the search tolerance and the min gap length to their default values Setting parameters lt AutoConfigure gt ON OFF 1 0 RST 1 Manual operation See Burst Configuration on page 166 SENSe DDEMod SEARch BURSt GLENgth MINimum lt MinGapLength gt This command defines the minimum time between two bursts A minimum time with decreased level must occur between two bursts The default unit is symbol The value can also be given in seconds Setting param
135. STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FDERror CURRent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FDERror MEAN STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FDERror PEAK STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FERRor PCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FERRor PMEan STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FERRor PPEak STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FERRor RCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FERRor RMEan STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy FERRor RPEak STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy MERRor PCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy MERRor PMEan STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy MERRor PPEak STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy MERRor RCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy MERRor RMEan STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy MERRor RPEak STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy OOFFset CURRent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy OOFFset MEAN STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy OOFFset PEAK STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy PERRor PCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy PERRor PMEa
136. See Enabling Pattern Searches on page 167 See Pattern Search On on page 171 Configuring Patterns New patterns can be defined and assigned to a signal standard Useful commands for configuring patterns described elsewhere SENSe DDEMod SEARch SYNC STATe on page 312 SENSe DDEMod SEARCh SYNC CATalog on page 286 Remote commands exclusive to configuring patterns ISENSe IDDEMod SEARCh S YNO GOMMMBRnI 42 terat a Xx EUR 312 SENSe IDDEMod SEARch S YNG GOBY repete iere tta eter eere pane 313 I SENSeJDDEMod SEARGh SYNO DElLgle iiie entes etta rena eed 313 SENSe DDEMod SEAR CHS chases esee euo unco 313 I SENSe IDDEMod SEARCMESYNGONNAME intet rato E ume Eee e eon tuu 314 8 440 314 315 315 SENSe DDEMod iSEARGhIS YNCETEXT accro eun tee 315 SENSe DDEMod SEARch SYNC COMMent Comment This command defines a comment to a sync pattern The pattern must have been selected be
137. Setting parameters lt LimitValue gt numeric value Range 200 0 to 0 0 RST 40 0 mean 45 0 Default unit DB CALCulate lt n gt LIMit MACCuracy PERRor PCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy PERRor PMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy PERRor PPEak VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy PERRor RCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy PERRor RMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy PERRor RPEak VALue lt LimitValue gt This command defines the value for the current peak or mean phase error peak or RMS limit Note that the limits for the current and the peak value are always kept iden tical Setting parameters lt LimitValue gt numeric value the value x x gt 0 defines the interval x x Range 0 0 to 360 RST 3 5 RMS 1 5 Default unit deg User Manual 1176 8516 02 06 353 11 7 4 Analysis CALCulate n LIMit MACCuracy RHO CURRent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy RHO MEAN VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy RHO PEAK VALue lt LimitValue gt This command defines the lower limit for the current peak or mean Rho limit Note that the limits for the current and the peak value are always kept identical Setting parameters lt LimitValue gt numeric value Range 0 0 to 1 0 RST 0 999 mean 0 9995 Default unit NONE
138. Standard The pattern is removed from the list of Standard Patterns and is no longer assigned to the current standard but is still available for assignment from the list of All Patterns 8 2 2 2 How to Define a New Pattern 1 In the Overview select Signal Description and switch to the Signal Structure tab 2 Select Pattern Config to display the Advanced Pattern Settings dialog box 3 Select the New button The pattern definition dialog box is displayed 4 Define the following pattern settings Setting Description Name Pattern name that will be displayed in selection list Description Optional description of the pattern which is displayed in the pattern details Modulation order Number of values each symbol can represent e g 8 for 8 PSK Comment Optional comment for the pattern displayed in the pattern details kept for compatibility with FSQ 5 Define the format used to define the individual symbols of the pattern 6 Define the symbols of the pattern How to Perform Customized Measurements Select the symbol field you want to define If necessary add a new symbol field by selecting Add b Enter a value using the keyboard Depending on the Modulation Order lt gt the value can be in the range 0 to n 1 Select the next symbol field or insert a new and continue to define the other symbols To scroll through the fields for long patterns use
139. Stop 10 sym traces C Mag CapBuf 1 traces Blank Meas Ref Meas Ref 20 dBm Preset Select Select 40 dBm All Traces Avg ClrWrite Min 60 dBm Trace Wizard 80 dBm d Start 0 sym Stop 1500 sym Start 2 535 Stop 2 535 15 03 2010 08 32 29 5 Trace Wizard Screen Measuring User Manual 1176 8516 02 06 256 R amp S FPS K70 Optimizing and Troubleshooting the Measurement Problem The spectrum is not displayed in the logarithmic domain Solution e 1 Select the measurement window 2 Press the AMPT key 3 Press the Unit softkey 4 Press the Y Axis Unit softkey 5 Select dB Problem The Vector I Q result display and the Constellation result display look different Spectrum VSA Ref Level 1 96 dBm Std EDGE_8PSK SR 270 833 kHz Att 22 dB Freq 1 0GHz Res Len 148 SGL BURST PATTERN i Crw Const I1 Q Meas amp Ref e 1M Clrw Start 0 sym sym Start 2 91 Stop 2 91 i Crw D 1 Q Meas amp Ref iM Clrw Start 0 sym Stop 1500 sym Start 2 91 l Stop 2 91 NIY 16 03 2010 10 08 34 Date 16 MAR 2010 10 08 34 Reason e The Vector I Q diagram shows the measurement signal after the measurement fil ter and synchronization e Constellation diagram shows the de rotated constellation i e for a rr 4 DQPSK 4 instead of 8
140. This command selects manual or automatic synchronization with a pattern waveform to speed up measurements Setting parameters lt UseWfmForSync gt AUTO MANual RST AUTO Manual operation See Coarse Synchronization on page 183 SENSe DDEMod SEARch PATTern SYNC STATe lt FastSync gt This command switches fast synchronization on and off if you manually synchronize with a waveform pattern Setting parameters lt FastSync gt ON OFF 1 0 RST 0 Manual operation See Coarse Synchronization on page 183 11 5 9 Measurement Filter Settings You can configure the measurement filter to be used Manual configuration of the measurement filter is described in chapter 5 10 Measure ment Filter Settings on page 185 For more information on measurement filters refer to chapter 4 1 4 Measurement Fil ters on page 59 Useful commands for defining measurement filters described elsewhere SENSe DDEMod FILTer ALPHa on page 277 SENSe DDEMod FILTer STATe on 278 Configuring VSA Remote commands exclusive to configuring measurement filters I SENSeTDDEMod MFIEter ABPHG 2 ot err eee tete ge xe eciam 327 SENS amp e IDDBEMGGMEIEter AUT uui iii etai oet act ree eene eee 327 SENSe IDDEMOdSMFIEtGENAME 2 iiu o rre as eere ee 327 SENSe DDEMod MFILter STATe ceca 327 SENSeJDDENGGMEIEter USB
141. Toggles the marker type The type for marker 1 is always Normal the type for delta marker 1 is always Delta These types cannot be changed Note If normal marker 1 is the active marker switching the Mkr Type activates an additional delta marker 1 For any other marker switching the marker type does not activate an additional marker it only switches the type of the selected marker Normal A normal marker indicates the absolute value at the defined position in the diagram Delta A delta marker defines the value of the marker relative to the speci fied reference marker marker 1 by default Remote command CALCulate n MARKer m STATe on 341 CALCulate lt n gt DELTamarker lt m gt STATe on 342 Assigning the Marker to a Trace The Trace setting assigns the selected marker to an active trace The trace deter mines which value the marker shows at the marker position If the marker was previ ously assigned to a different trace the marker remains on the previous frequency or time but indicates the value of the new trace The marker can also be assigned to the currently active trace using the Marker to Trace softkey in the Marker menu If a trace is turned off the assigned markers and marker functions are also deactiva ted Remote command CALCulate lt n gt MARKer lt m gt TRACe page 341 All Markers Off Deactivates all markers in one step Remote command CALCulate lt n gt
142. WINDow lt n gt TRACe lt t gt Y SCALe MODE on page 370 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 3 2 15 Frequency Response Group Delay The Frequency Response Group Delay of the equalizer is the derivation of phase over frequency It is a measure of phase distortion User Manual 1176 8516 02 06 34 R amp S FPS K70 Measurements and Result Displays 3 GroupDelay Equalizer Start 100 MHz Stop 100 MHz Available for source types e Equalizer Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow page 359 CALC FEED XFR DDEM RAT to define the frequency response result type see CALCulate lt n gt FEED on page 365 CALC FORM GDEL to define the group delay result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 6 Equalizer on page 377 3 2 16 Frequency Response Magnitude Frequency response of the current equalizer to the input signal Note that the fre quency response of the equalizer is not a pure inverted function of the channel response as both functions are calculated independantly The frequency response is calculated by determining an optimal EVM for the input signal User M
143. Wide Pulse 20 gp Ag eee 100 0 8 0 6 0 4 0 2 Frequency in EDGE NSR 20 4 4 4 1 gp 100 fsymbol Frequency in w Narro Low Pass 20 1 4 D Hess 4 4 sali 1 4 2 1 4 BD L D 4 06 08 1 2 1 4 1 6 1 8 fsymbol 0 2 100 Frequency in Formulae Low Pass Wide 20 4 4 4 gp 1 4 BO L 100 14 16 18 1 2 0 8 0 6 0 4 0 2 Frequency in f ymbol Rectangular 20 S 1 8 1 6 1 4 1 2 feymbol 0 8 0 6 0 4 8 Sere Cee ee Cee eee M 4 2 0 240 60 HE 80 100 gp Frequency in ISI Filters Low The following frequency responses are obtained when usi
144. XTIM DDEM MACC switch on result summary in screen 2 CALC2 LIM MACC CFER CURR VAL 100 Hz define a limit of 100 100 CALC2 LIM MACC CFER CURR STAT ON switch limit check ON See Check on page 201 CALCulate lt n gt LIMit MACCuracy CFERror CURRent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy CFERror MEAN VALue lt LimitValue gt CALCulate n LIMit MACCuracy CFERror PEAK VALue lt LimitValue gt This command defines the limit for the current peak or mean center frequency error limit Note that the limits for the current and the peak value are always kept identical Setting parameters lt LimitValue gt numeric value the value x gt 0 defines the interval x x Range 0 0 to 1000000 RST 1000 0 mean 750 0 Default unit Hz R amp S FPS K70 Remote Commands for VSA _ lt CALCulate lt n gt LIMit MACCuracy EVM PCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy EVM PMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy EVM PPEak VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy EVM RCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy EVM RMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy EVM RPEak VALue lt LimitValue gt This command defines the val
145. a command supports more than one parameter these are separated by a comma Example LAYout ADD WINDow Spectrum LEFT MTABle Parameters may have different forms of values Values SE 267 e Bogen tee iD IT ravi ee rd 268 MESI 0438 RRR 268 e Character teta ee trt 269 e Block eter d e E eee re vedete Enero cda ve dete 269 11 1 6 1 Numeric Values Numeric values can be entered in any form i e with sign decimal point or exponent In case of physical quantities you can also add the unit If the unit is missing the com mand uses the basic unit Example with unit SENSe FREQuency CENTer 1GHZ without unit SENSe FREQuency CENTer 1 9 would also set a frequency of 1 GHz Values exceeding the resolution of the instrument are rounded up or down If the number you have entered is not supported e g in case of discrete steps the command returns an error Instead of a number you can also set numeric values with a text parameter in special cases Defines the minimum or maximum numeric value that is supported e DEF Defines the default value 11 1 6 2 11 1 6 3 Introduction e UP DOWN Increases or decreases the numeric value by one step The step size depends on the setting In some cases you can customize the step size
146. amp S FPS K30 NOISE Noise Phase Noise R amp S FPS K40 PNOISE Phase Noise VSA R amp S FPS K70 DDEM VSA 3GPP FDD BTS R amp S FPS K72 BWCD 3G FDD BTS 3GPP FDD UE R amp S FPS K73 MWCD 3G FDD UE TD SCDMA BTS R amp S FPS K76 BTDS TD SCDMA BTS TD SCDMA UE R amp S FPS K77 MTDS TD SCDMA UE cdma2000 BTS R amp S FPS K82 BC2K CDMA2000 BTS cdma2000 MS R amp S FPS K83 MC2K CDMA2000 MS 1xEV DO BTS R amp S FPS K84 BDO 1xEV DO BTS 1xEV DO MS R amp S FPS K85 MDO 1xEV DO MS WLAN R amp S FPS K91 WLAN WLAN LTE R amp S FPS K10x LTE LTE Note the default channel name is also listed in the table If the specified name for a new channel already exists the default name extended by a sequential number is used for the new channel INSTrument REName lt ChannelName1 gt lt ChannelName2 gt This command renames a measurement channel Parameters lt ChannelName1 gt String containing the name of the channel you want to rename lt ChannelName2 gt String containing the new channel name Note that you can not assign an existing channel name to a new channel this will cause an error Example INST REN Spectrum2 Spectrum3 Renames the channel with the name Spectrum2 to Spectrum3 Usage Setting only INSTrument SELect lt ChannelType gt Selects the application channel type for the current channel Digital Standards See also INSTrument CREate NEW on page 270 For a list of available channel types see table 11
147. and chapter 11 9 2 6 Equalizer on page 377 Impulse Response Magnitude The impulse response magnitude of the equalizer shows the filter in the time domain 3 ImpRespMag Equalizer Start 5 sym Stop 5 sym Available for source types e Equalizer Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow 2 page 359 CALC FEED XTIM DDEM IMP to define the impulse response result type see CALCulate lt n gt FEED on page 365 CALC FORM MAGN to define the magnitude result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 6 Equalizer on page 377 User Manual 1176 8516 02 06 37 R amp S9FPS K70 Measurements and Result Displays 3 2 19 3 2 20 Impulse Response Phase The Impulse Response Phase is the derivation of the Impulse Response Magnitude 4 ImpRespPhas Equalizer Start 5 sym Stop 5 sym Available for source types e Equalizer Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow page 359 CALC FEED XTIM DDEM IMP to define the impulse response result type see CALCulate lt n gt FEED on page 365 CALC FORM UPH to define the phase result type see CALCulate lt n gt FORMat on p
148. are highlighted The running measurement can be aborted by selecting the highlighted softkey or key again Remote command INITiate lt n gt CONMeas on 333 Refresh non Multistandard mode Repeats the evaluation of the data currently in the capture buffer without capturing new data This is useful after changing settings for example filters patterns or evaluation ranges Remote command INITiate REFMeas on page 334 Statistic Count Defines the number of measurements to be considered for statistical evaluations The behavior depends on the active sweep mode Signal Capture Activate Description to display a visualization of the behavior of the current settings Note If the Statistic Count is set to 1 trace averaging is not performed Max Hold and Min Hold however remain active unlike in the Spectrum application Auto In single sweep mode captures the data once and evaluates it In continuous sweep mode captures data continuously for each evaluation the average is calculated over the last 10 capture sets moving average Manual In single sweep mode captures data until the defined number of evaluations have been performed In continuous sweep mode captures data continuously if trace averaging is selected the average is calculated over the defined number of capture sets moving average Remote command SENSe SWEep COUNt VALue on 307 Select Result Rng Selec
149. based coarse synchroni zation might be unstable If demodulation is stable e g you get a reasonable EVM there is no need to change anything Otherwise you have two options e Switch to the non pattern based mode by setting the parameter Coarse Synchro nization Data pum EIN RN DANN M NUUS User Manual 1176 8516 02 06 254 10 3 Frequently Asked Questions see Coarse Synchronization on page 183 f possible use a longer pattern For more information see chapter 4 4 Overview of the Demodulation Process on page 88 Message Result Ranges Overlap This message does not indicate an error It is merely displayed to inform you that the defined result ranges in the capture buffer overlap Thus some captured data is evalu ated more than once For example the same peak value may be listed several times if it is included in several result ranges and averaging is performed on partially dupli cate values However a negative influence on the measurement results is not to be expected Frequently Asked Questions Problem The trace is not entirely visible within the measurement window 255 Problem The trace of the measurement signal is visible in the measurement window the trace of the reference signal Is not nnns 255 Problem The measurement window does not show average 256 Problem The spectrum is not displayed in the logarithmic domain
150. before the next command For details see the Remote Basics chapter in the R amp S FPS User Manual To abort a sequence of measurements by the Sequencer use the INITiate lt n gt SEQuencer ABORt command Note on blocked remote control programs If a sequential command cannot be completed for example because a triggered sweep never receives a trigger the remote control program will never finish and the remote channel to the R amp S FPS is blocked for further commands In this case you must inter rupt processing on the remote channel first in order to abort the measurement Performing a Measurement To do so send a Device Clear command from the control instrument to the R amp S FPS on a parallel channel to clear all currently active remote channels Depending on the used interface and protocol send the following commands Visa viClear Now you can send the ABORt command on the remote channel performing the mea surement Example ABOR INIT IMM Aborts the current measurement and immediately starts a new one Example ABOR WAI INIT IMM Aborts the current measurement and starts a new one once abortion has been completed Usage Event SCPI confirmed INITiate lt n gt CONMeas This command restarts a single measurement that has been stopped using ABORt or finished in single measurement mode The measurement is restarted at the beginning not where the previous measurement was stopped As opp
151. cation in the pass band Low Pass Narrow Pass band up to Feymbo 2 Stop band starts at Fsymboi 40dB Low Pass Wide Pass band up to Fo Stop band starts at 1 5 F symbo1 40dB Rectangular Rectangular filter in the time domain with a length of 1 symbol period integrate and dump effect RRC Root Raised Cosine Filter The roll off parameter Alpha is set according to the Transmit filter if the Auto according to Trans mit filter option is enabled see Using the Transmit Filter as a Measurement Filter Auto on page 186 Otherwise it must be set manually If the Transmit filter is also a Root Raised Cosine filter with the same roll off parameter the resulting system is inter symbol interference free USER User defined filter Define the filter using the Load User Filter function or the SENSe DDEMod MFILter USER command For details see chapter 8 2 1 How to Select User Defined Fil ters on page 213 NONE No measurement filter is used The frequency response of the available standard specific measurement filters is shown in chapter A 6 6 2 Measurement Filter on page 433 R amp S FPS K70 Annex A 3 3 Typical Combinations of Tx and Measurement Filters Typical combinations of Tx and Meas filters are shown in table 1 4 they can be set in the VSA application using Meas filter AUTO see Using the Transmit Filter as a Measurement Filter Auto on page 186
152. chapter 4 5 1 2 Estimation on page 101 Solution e signal contains a pattern set Coarse Synchronization Pattern see Coarse Synchronization on page 183 Example measurement of a GSM EDGE pattern that has a length of 26 symbols Mag CapBuf amp e1clw D Const I Q Meas amp Ref 1M Clrw 20 dBm 40 deBry 60 dBm Stop 200 sym Start 2 91 Stop 2 91 1 08 21 13 D Const 8 1M Clrw 20 dBm 40 dBriy 60 dBm Start 0 sym Stop 2 91 Fig 10 11 User Pattern for Sync On e Choose a longer Result Range e signal is bursted and the bursts are short Make sure your Result Range comprises the entire burst sure that Run In Out is not chosen too large since the Run In Out ranges are excluded from the synchronization e signal is bursted and contains a pattern Only switch off the burst search if absolutely necessary If you need to switch it off align your Result Range to the pattern make sure it does not exceed the burst ramps and choose Continuous Signal as the Signal Type in the Signal Descrip tion dialog For more information see e chapter 4 4 Overview of the Demodulation Process on page 88 Message Sync Prefers Longer Pattern This message can only occur if the coarse synchronization is data aided i e is based on a known pattern In case the pattern is very short pattern
153. chapter 5 1 Default Settings for Vector Signal Analysis on page 128 for details Remote command SYSTem PRESet CHANnel EXECute on page 273 Specifics for The measurement channel may contain several windows for different results Thus the settings indicated in the Overview and configured in the dialog boxes vary depending on the selected window Select an active window from the Specifics for selection list that is displayed in the Overview and in all window specific configuration dialog boxes Enable the Specifics for option The Overview and dialog boxes are updated to indicate the settings for the selected window The indicated data flow is updated for the selected data source If the Specifics for option is not enabled the overview displays the default data flow and the general settings independently of the selected window Note The Display Config button is only available in the general overview not in the window specific overview Signal Description Digital Standards Opens file selection dialog to manage predefined measurement settings for conven tional mobile radio standards See chapter 5 2 Configuration According to Digital Standards on page 129 5 4 Signal Description The signal description provides information on the expected input signal which optimi zes burst and pattern detection and allows for the application to calculate an ideal ref erence signal The signal de
154. checking enabling 200 Limit remote eite 349 Limits Result types Modulation Error Ratio MER DEMHON Modulation errors Data t de e seva NS PSK QAM MSK 2 Res lt types aciari neitar Modulation order eaa 123 Pattern symbols oae tn tr rtt 173 Modulation type ip 110 MSK Error model 100 Modulation type eee mtt nes 135 MSRA Analysis interval 156 301 Operating mode etn ener eer MSRA applications Capture i rnt tren es 161 Capture offset remote 355 Multiple Measurement channels issiria 11 Multiple ZOOM tereti ntn e rre t teres 205 N Next 198 Marker positioning 198 Next Peak 2e 198 Marker positionilig acit ect eene 198 Noise ja 110 Normalization Demodulatior eate iere 181 Offset Analysis imena issin nsnsi ce ath ci ea 161 EVM inis Frequency Pattern m QPSK ab QPSK symbol mapping 75 Reference level a Off Keying Constellation diagram 85
155. data is used Demodulation Settings Note You can define a maximum symbol error rate SER for the known data in refer ence to the evaluated data If the SER of the known data exceeds this limit the default synchronization using the detected data is performed Known Data reference signal is defined as the data sequence from the loaded Known Data file that most closely matches the measured data Pattern The reference signal is estimated from the defined pattern Detected Default The reference signal is estimated from the detected data Data Remote command SENSe DDEMod FSYNc AUTO on 322 SENSe DDEMod FSYNc MODE on page 323 SENSe DDEMod FSYNc RESult on page 323 If SER S This setting is only available if Known Data is selected for Fine Synchronization You can define a maximum symbol error rate for the known data in reference to the evaluated data Thus if a wrong file was mistakenly loaded or the file proves to be unsuitable it is not used for synchronization Otherwise the results would be strongly distorted If the SER of the known data exceeds this limit the default synchronization using the detected data is performed Remote command 5 5 DDEMod FSYNc LEVel on page 322 Offset EVM The offset EVM is only available for Offset QPSK modulated signals Unlike QPSK modulation the Q component of Offset QPSK modulation is delayed by half a symbol peri
156. ei M Signal model 1t htt etr mies Signal source cs 288 Signal structure Buist settihgs c re rere ett Enea 140 Configuration 2 138 REMOS e 284 Signal type Continuous Burst Signal 139 Single sweep SOfIKGy ieu a ee ees 162 SMIE ZOOM 205 Slope 161 306 Softkeys Amplitude Configs en 147 Auto 148 188 Capture Offset 3e tertie t 161 146 Continue Single Sweep 162 Continuous Sweep 242161 Display configuration 201 207 M 159 Free RUM 2159 Frequency Config 146 Power 160 IF Power 4 159 Import 207 Input Source CONTIG mter 142 Input Frontend ii eee ets 142 IQ Export IQ Import Lower Level Hysteresis asserisson 189 Marker Config 194 Marker to Trace Meastime Auto Meastime Manual MIEL aa 198 MOGdACO LIMIS rE 200 iet ra 198 Next Peak 198 Norm Delta 196 Outputs Config 144
157. estimation see Estimation Points Sym on page 182 For estimation of the frequency parameters the following least squares criterion is minimized 2 8 fos fast B frer 1 7 fa n Tr with respect to the model parameters B fo f 7 The term denotes the reference instantaneous frequency with a possibly fractional delay of samples For FSK modulation the default sampling period used for estimation is the capture sampling period 4 5 2 3 Modulation Errors A 2FSK signal is generated using a GMSK frequency pulse Examples of carrier drift and reference deviation are shown in figure 4 61 and figure 4 62 respectively Signal Model Estimation and Modulation Errors Carrier frequency drift A carrier frequency drift is modeled as a linear change in the carrier frequency with respect to time The effect of carrier drift on the instantaneous frequency of an FSK signal is illustrated in figure 4 61 Instantaneous Frequency GMSK Modulation 1 5 a Frequency Ref Deviation e Freq Ref Freq Meas 0 5 10 15 20 25 30 Time Symbols Fig 4 61 The reference and distorted instantaneous frequency of a GMSK signal with a carrier fre quency drift FSK deviation error The FSK deviation error is the difference between the measured frequency deviation and the reference frequency deviation as entered by the user see FSK Ref Deviation FSK only on page 137
158. for each active channel Thus if a status bit in the STATus QUEStionable register indicates an error the error may have occurred in any of the channel specific subregisters In this case you must check the subregister of each channel to determine which channel caused the error By default querying the status of a subregister always returns the result for the currently selected channel D The STATus QUESt ionable register sums up the information from all subregisters The commands to query the contents of the following status registers are described in chapter 11 11 9 Querying the Status Registers on page 397 Status Reporting System g sogea OR of all Lits s g DigtallQ o specific for FSW K70 13 1 One register for each active channel pu ACPLimit SYNC SYNC BURSt E LMARgN STATus QUEStionable SYNC lt n gt T 5 CALibration UNCAL MODulation 5 FREQuency FDEMean POWer 2 FDECurrent STATus QUEStionable PIOQOffset 7 PFECurrent MIQOfset CIQOffset PPEsk RFEPask PCURrent RFEMean PRHo RFECurrent MRHo t CRHa RPEak 7 RMEan IQRHo STAT QUES MOO IOR RCURrent STAT QUES MOO CFR MAGNitude STAT QUES MOO MAGN PRINSE STAT QUES MOD PHAS STAT QUES MOD EVM STATus QUEStionable MODulation n Fig 11 2 Overview of VSA spec
159. gap length minimum burst length and maximum burst length see Burst Set tings on page 140 and Min Gap Length on page 166 Refer to figure 4 43 for an illustration of the three parameters The detected bursts in the capture buffer for the current burst search settings are indi cated by blue lines in the preview area of the Burst Search configuration dialog box see chapter 5 7 1 Burst Search on page 164 Information Expected Burst Length 148 4 sym Burst Found Preview Preview Mag CapBuf Start 0 sym Stop 1500 sym User Manual 1176 8516 02 06 91 Overview of the Demodulation Process Power Averaged Calculate Average Filter Length Calculate Threshold Find Next Rising amp Falling Edge Calculate Acceptable Burst Lengths Burst Length Okay Add to Burst List Fig 4 44 Burst search algorithm 4 4 2 19 Pattern Search The pattern search is performed only if it is switched on Otherwise this stage is skipped The main benefit of the pattern search is that it enables an alignment of the result range to the pattern Furthermore this stage can function as a filter If the burst search and pattern search are switched on and the parameter Meas Only If Pattern Symbols Correct is set to true only bursts with the correct pattern are demodulated see Meas only if Pattern Symbols Correct on page 168 During the pattern search stage the capture buffer is s
160. in chap ter 4 3 4 Rotating Differential PSK Modulation on page 74 Fig 4 19 Constellation diagram for DQPSK INMARSAT and NATURAL including the symbol map ping Table 4 3 DQPSK INMARSAT Logical symbol mapping Modulation symbol binary indication MSB LSB 00 01 10 11 Phase shift 0 90 90 180 4 3 4 Symbol Mapping Fig 4 20 Constellation diagram for D8PSK including the symbol mapping for APCO25 APCO25 Phase 2 GRAY NATURAL and TETRA Table 4 4 DBPSK NATURAL Logical symbol mapping Modulation symbol binary indica 000 001 010 011 100 101 110 111 tion MSB LSB Phase shift 0 45 90 135 180 225 270 315 Table 4 5 D8PSK GRAY Logical symbol mapping Modulation symbol binary indica 000 001 010 011 100 101 110 111 tion MSB LSB Phase shift 0 45 135 90 270 315 225 180 Table 4 6 D8PSK VDL Logical symbol mapping Modulation symbol binary indica 000 001 010 011 100 101 110 111 tion MSB LSB Phase shift 0 45 135 90 315 270 180 225 Rotating Differential PSK Modulation Phase differential modulation is frequently combined with an additional phase shift e g 4 DQPSK 4 phase shift modulation differential modulated 4PSK The logical mapping diagram corresponds to the diagram for DPSK The
161. in the input signal you can define a hysteresis This setting defines a lower threshold the signal must fall below compared to the last measurement before the reference level is adapted auto matically Parameters Threshold Range dB to 200 dB RST 1dB Default unit dB Example SENS ADJ CONF HYST LOW 2 For an input signal level of currently 20 dBm the reference level will only be adjusted when the signal level falls below 18 dBm Manual operation See Lower Level Hysteresis on page 189 SENSe ADJust CONFigure HYSTeresis UPPer Threshold Parameters Threshold Range 0 dB to 200 dB RST 1dB Default unit dB Example SENS ADJ CONF HYST UPP 2 Example For an input signal level of currently 20 dBm the reference level will only be adjusted when the signal level rises above 22 dBm Manual operation See Upper Level Hysteresis on page 189 Performing a Measurement SENSe ADJust LEVel SENSe DDEMod PRESet RLEVel This command initiates a measurement that evaluates and sets the ideal reference level for the current measurement This ensures that the settings of the RF attenuation and the reference level are optimally adjusted to the signal level without overloading the R amp S FPS or limiting the dynamic range by an S N ratio that is too small Usage Event 11 6 Performing a Measurement When the application is activated a continuous sweep is performed automatically However you
162. int64 see DataType element Examples xyz complex 1ch float32 e xyz polar 1ch float64 e xyz eal 1ch int16 xyz complex 16ch int8 UserData Optional contains user application or device specific XML data which is not part of the iq tar specification This element can be used to store additional information e g the hardware configuration User data must be valid XML content PreviewData Optional contains further XML elements that provide a preview of the data The preview data is determined by the routine that saves an iq tar file e g R amp S FPS For the definition of this element refer to the RsIqTar xsd schema Note that the preview can be only displayed by current web browsers that have JavaScript enabled and if the XSLT stylesheet open xml file in web browser xslt is available Example ScalingFactor Data stored as int16 and a desired full scale voltage of 1 V ScalingFactor 1 V maximum int16 value 1 V 215 3 0517578125e 5 V Scaling Factor Numerical value Numerical value x ScalingFac tor Minimum negative int16 value 275 32768 1 Maximum positive int16 value 215 1 32767 0 999969482421875 V Example PreviewData in XML lt PreviewData gt lt ArrayOfChannel length 1 gt lt Channel gt lt PowerVsTime gt Data File Format iq tar lt Min gt lt ArrayOfFloat length 256 gt lt float gt 134 lt float gt lt float gt 14
163. is not limited to 180 180 Available for source types e Meas amp Ref Signal EM User Manual 1176 8516 02 06 45 R amp S9FPS K70 Measurements and Result Displays 3 2 28 1 Phase Meas amp Ref 1M Clrw 49 sym Fig 3 18 Result display Phase Unwrap Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM UPHase to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 Real Imag I Q Real and imaginary part of the measurement or reference signal in separate measure ment diagrams the x axis scaled in time units or symbols is identical for both dia grams Available for source types e Capture Buffer e Meas amp Ref Signal e Error Vector Capture buffer display Note that this result display is based on an individual capture buffer range If more than 256 000 samples are captured overlapping ranges with a size of 256 000 each are created Only one range at a time can be displayed in the Real Imag result display For details see chapter 4 8 Capture Buffer Display on page 122 SSS Ee a User Manual 1176 8516 02 06 46 R amp S FPS K70 Measurements and Result Displays The scaling of the capture buffer depends on the input source e Scal
164. is used RST NORMal Manual operation See Modulation Order on page 136 SENSe DDEMod QAM NSTate lt QAMNState gt This command defines the demodulation order for QAM lt QAMNSTate gt Order 16 16QAM 16 Pi 4 16QAM 32 32QAM 32 Pi 4 32QAM 64 64QAM 128 128QAM 256 256QAM 512 512QAM 1024 1024QAM Configuring VSA Setting parameters lt QAMNState gt numeric value RST 16 Manual operation See Modulation Order on page 136 SENSe DDEMod QPSK FORMat lt QPSKformat gt This command defines the demodulation order for QPSK Setting parameters lt QPSKformat gt NORMal DIFFerential 4 DPIA4 OFFSet 4 NORMal Demodulation order QPSK is used DIFFerential Demodulation order DOPSK is used 4 Demodulation order 4 QPSK is used DPI4 Demodulation order 4 DQPSK is used OFFSet Demodulation order OQPSK is used 4 Demodulation order 31 4 QPSK is used RST NORMal Example DDEM FORM QPSK Switches QPSK demodulation on DDEM QPSK FORM 4 Switches rr 4 DQPSK demodulation order on Example See chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Modulation Order on page 136 SENSe DDEMod SRATe lt SymbolRate gt This comman
165. longer coupled to the reference level but the reference level is coupled to the attenuation Thus if the current reference level is not compatible with an attenuation that has been set manually the command also adjusts the reference level Parameters lt Attenuation gt Range see data sheet Increment 5 dB RST 10 dB AUTO is set to ON Example INP ATT 30dB Defines a 30 dB attenuation and decouples the attenuation from the reference level Usage SCPI confirmed Manual operation See Attenuation Mode Value on page 149 Configuring VSA INPut ATTenuation AUTO State This command couples or decouples the attenuation to the reference level Thus when the reference level is changed the R amp S FPS determines the signal level for optimal internal data processing and sets the required attenuation accordingly Parameters State OFF 0 1 RST 1 Example INP ATT AUTO ON Couples the attenuation to the reference level Usage SCPI confirmed Manual operation See Attenuation Mode Value on page 149 INPut EATT lt Attenuation gt This command defines an electronic attenuation manually Automatic mode must be switched off INP EATT AUTO OFF see INPut EATT AUTO page 295 If the current reference level is not compatible with an attenuation that has been set manually the command also adjusts the reference level This command requires the electronic attenuation hardware option Parameters lt At
166. mode is automatically switched to USER see SENSe DDEMod EQUalizer MODE on page 321 Setting parameters Name string Path and file name without extension Example DDEM EQU LOAD D MMyEqualizer Selects equalizer named MyEqualizer in directory D Manual operation See Store Load Current Equalizer on page 180 SENSe DDEMod EQUalizer MODE Mode Switches between the equalizer modes For details see chapter 4 4 5 The Equalizer on page 97 Setting parameters Mode NORMal Switches the equalizer on for the next sweep TRACking Switches the equalizer on the results of the equalizer in the pre vious sweep are considered to calculate the new filter FREeze The filter is no longer changed the current equalizer values are used for subsequent sweeps USER A user defined equalizer loaded from a file is used AVERaging Switches the equalizer on the results of the equalizer in all pre vious sweeps since the instrument was switched on or the equalizer was reset are considered to calculate the new filter To start a new averaging process use the SENSe DDEMod EQUalizer RESet on page 322 command RST TRACe Example DDEM EQU MODE TRAC Activates the tracking mode of the equalizer Manual operation See Mode on page 179 Configuring VSA SENSe DDEMod EQUalizer RESet This command deletes the data of the currently selected equalizer After deletion tra
167. not affect the EVM Note that the gain imbalance is not estimated and cannot be compensated for in a BPSK signal The distortions gain imbalance and quadrature error can only be measured without ambiguity if the following two conditions are fullfilled o Preconditions for Gain Imbalance and Quadrature Error measurements e a pattern is detected the modulation is a non differential non rotating QAM PSK Otherwise only the measurement parameter Imbalance which is a combination of the gain imbalance and the quadrature error is significant Quadrature Error Fig 4 56 Effect of Quadrature Error The quadrature error is another modulation error which is shown in figure 4 56 In this diagram the and Q components of the modulated carrier are of identical ampli tude but the phase between the two components deviates from 90 This error also distorts the coordinates In the example in figure 4 56 the Q axis is shif ted Note that the quadrature error is not estimated and cannot be compensated for in a BPSK signal Imbalance The effect of quadrature error and gain imbalance are combined to form the error parameter imbalance Signal Model Estimation and Modulation Errors ie go e Buin le 20 where and are the gain of the inphase and the quadrature component rep resents the quadrature error The imbalance can be compensated for if the correspond
168. not on the R amp S FPS K70 or Why I have to choose different transmit filters in the R amp S FSQ K70 and the R amp S FPS K70 When generating an MSK FSK reference signal the R amp S FSQ K70 automatically replaces the Dirac pulses generated by the frequency mapper with square pulses with the length of one symbol In the R amp S FPS K70 however this replacement is part of the transmit filter routine Thus the R amp S FSQ and the R amp S FPS require different trans mit filters for measuring the same FSK MSK signal Example e f your transmit filter for the R amp S FSQ K70 was NONE you need to choose Rec tangular as the transmit filter type in the R amp S FPS e f your transmit filter for the R amp S FSQ K70 was GAUSS you need to choose GMSK as the transmit filter type in the R amp S FPS Problem The EVM trace looks okay but the EVM in the result summary is signif icantly different Solution e sure that the position of the Evaluation Lines is reasonable The Result Summary only evaluates sample instants that are within the evaluation lines Hence in the case the Result Range covers the burst ramps it is important to adjust the Evaluation Range appropriately reer User Manual 1176 8516 02 06 258 R amp S FPS K70 Optimizing and Troubleshooting the Measurement Spectrum VSA Ref Level 0 00 dBm Std EDGE 16QAM SR 270 833 kHz m tel Att 20 0 dB Freq 1 0GHz Res Len 300 SGL ResRange Count 0 BURST
169. on the screen Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic CFERror lt type gt This command queries the results of the carrier frequency error measurement per formed for digital demodulation The output values are the same as those provided in the Modulation Accuracy table Query parameters lt type gt lt none gt Carrier frequency error for current sweep AVG Average carrier frequency error over several sweeps RPE Peak carrier frequency error over several sweeps SDEV Standard deviation of frequency error PCTL 95 percentile value of frequency error Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Usage Query only Retrieving Results CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic EVM type This command queries the results of the error vector magnitude measurement of digital demodulation The output values are the same as those provided in the Modulation Accuracy table Query parameters type none RMS EVM value of display points of current sweep Average of RMS EVM values over several sweeps PAVG Average of maximum EVM values over several sweeps PCTL 9595 percentile of RMS EVM value over several sweeps PEAK Maximum EVM over all symbols of current sweep PPCT 95 percentile of maximum EVM values over several sweeps PSD Standard deviation of maximum EVM values over sever
170. page 297 Configuring a Reference Point and Divisions Defines the displayed range using a reference point and the size of the divisions Y Axis Reference Value Configuring a Reference Point and Divisions Defines a reference value on the y axis in the current unit The y axis is adapted so that the reference value is displayed at the Y Axis Reference Position on page 152 Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RVALue on page 300 Y Axis Reference Position Configuring a Reference Point and Divisions Defines the position of the Y Axis Reference Value on the y axis The position is defined as a percentage value where 0 refers to the bottom edge 100 refers to the top edge of the screen The y axis is adapted so that the reference value is dis played at the reference position Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RPOSition on page 300 Range per Division Configuring a Reference Point and Divisions Defines the value range to be displayed per division Since the display consists of 10 divisions by default the displayed range is Range 10 lt Range per Division gt Note If fewer divisions are displayed e g because the window is reduced in height the range per division is increased in order to display the same result range in the smaller window In this case the per division value does not correspond to the actual display Remote command DISPlay
171. page 302 Sample Rate Defines the number of samples to capture per symbol The sample rate in MHz is indi cated for reference This parameter affects the demodulation bandwidth and thus the usable bandwidth The maximum sample rate depends on the defined Symbol Rate see chapter 4 2 Sample Rate Symbol Rate and Bandwidth on page 63 For details on selecting the suitable sample rate see chapter 4 2 Sample Rate Sym bol Rate and Bandwidth on page 63 Remote command SENSe DDEMod PRATe on page 301 Usable Bandwidth Shows the usable bandwidth which depends on the selected sample rate For details see chapter 4 2 Sample Rate Symbol Rate and Bandwidth on page 63 This information is provided for reference only Note 5 6 2 Signal Capture In diagrams in the frequency domain Spectrum transformation see Result Type Transformation on page 202 the usable bandwidth is indicated by vertical blue lines Remote command TRACe lt n gt 1Q BWIDth on page 303 Swap Activates or deactivates the inverted modulation If the and Q parts of the signal from the DUT are interchanged the R amp S FPS can do the same to compensate for it On Q signals are interchanged Inverted sideband Q j l Off and Q signals are not interchanged Normal sideband I j Q Remote command SENSe SWAPiq on page 302 Trigger Settings Th
172. physical constellation diagram shows the symbol decision points obtained after ISI free demodulation Symbol Mapping Fig 4 21 Constellation diagram for 7 4 DQPSK including the symbol mapping APCO25 Phase 2 NATURAL PDC PHS TETRA and TFTS the 774 rotation is already compensa ted for Table 4 7 7 4 DQPSK PDC PHS Logical symbol mapping Modulation symbol binary indication MSB LSB 00 01 10 11 Phase shift 02 45 90 45 90 45 180 45 Table 4 8 77 4 DQPSK TFTS Logical symbol mapping Modulation symbol binary indication MSB LSB 00 01 10 11 Phase shift 180 45 90 45 90 45 0 45 Table 4 9 1 4 DQPSK Natural Logical symbol mapping Modulation symbol binary indication MSB LSB 00 01 10 11 Phase shift 0 45 90 45 180 45 90 45 Table 4 10 774 DQPSK APCO25 and APCO25Phase2 Logical symbol mapping Modulation symbol binary indication MSB LSB 00 01 10 11 Phase shift 02 45 90 45 90 45 180 45 4 3 5 Offset QPSK Offset QPSK differs from normal QPSK in the fact that the Q component is delayed by half a symbol period against the component in the time domain Hence the symbol time instants of the and the Q component do not coincide The concept of Offset QPSK is illustrated in the diagrams below 5
173. points are displayed The inter symbol interference has been removed In case the measurement filter does not remove the inter symbol interference the win dows show measurements that are significantly different Problem The Constellation measurement result display has a different num ber of constellation points in the R amp S FSQ K70 and the R amp S FPS K70 Reason User Manual 1176 8516 02 06 257 R amp S FPS K70 Optimizing and Troubleshooting the Measurement SESE EEE sy In the FSQ K70 the Constellation measurement displays the symbol instants of the Vector measurement Hence this is a rotated constellation e g for a 1 4 DQPSK 8 points are displayed In the R amp S FPS K70 the Constellation diagram shows the de rotated constellation i e for a rr A DQPSK 4 instead of 8 points are displayed The inter symbol interfer ence has been removed Note The result display I Q Constellation Rotated displays the rotated constella tion as the FSQ K70 does For details on the Constellation I Q diagram the R amp S FPS K70 see chapter 3 2 5 Constellation on page 24 Table 10 1 Constellation and Vector 1 0 for pi 4 DQPSK modulation Std TETRA_ContinousDownlink SR 18 0 kHz L 255 C Constellation I Q Meas amp Ref 1M Clrw Start 5 13 D Vector I Q Meas amp Ref R amp S FSQ K70 R amp S FPS K70 Problem the MSK FSK signal demodulates on the R amp S FSQ K70 but
174. ramps in detail by selecting the alignment Burst Center The maximum result length is 64 000 symbols for a sample rate of 4 or 256 000 sam ples Result Range Alignment By defining the number of the symbol which marks the beginning of the alignment ref erence source burst capture buffer or pattern you can define an offset of the x axis in addition to the one defined for the signal structure see Offset on page 141 For example if you align the result to the center of the pattern and set the Symbol Number at Pattern Start to O you can easily find the pattern start in the EVM mea surement simply by moving a marker to the symbol number 0 When you define the Symbol Number at Reference Start remember to take the off set defined for the signal structure into consideration see Offset on page 141 If you define an offset of the pattern with respect to the useful part of the burst in the signal description and align the result to the pattern the Symbol Number at Pattern Start refers to the first symbol of the useful part of the burst not the first symbol of the pat tern Run In Run Out Time The parameter Run In Out can be used to influence the range over which the EVM is minimized The internal synchronization range is the overlapping area of the result range and the burst excluding its Run In Out areas Hence this parameter also allows for demodulation of bursts with mixed modulations e g Bluetooth
175. result displays of the application need not analyze the com plete data range The data range that is actually analyzed by the individual result dis play is referred to as the analysis interval In the R amp S FPS VSA application the analysis interval is automatically determined according to the evaluation range or result range settings as in Signal and Spectrum Analyzer mode The currently used analysis interval in seconds related to capture buffer start is indicated in the window header for each result display Exception Equalizer In the Equalizer displays do not indicate the analysis interval in MSRA mode Analysis line A frequent question when analyzing multi standard signals is how each data channel is correlated in time to others Thus an analysis line has been introduced The analysis line is a common time marker for all MSRA applications It can be positioned in any MSRA application or the MSRA Master and is then adjusted in all other applications Thus you can easily analyze the results at a specific time in the measurement in all applications and determine correlations If the marked point in time is contained in the analysis interval of the application the line is indicated in all time based result displays such as time symbol slot or bit dia grams By default the analysis line is displayed however it can be hidden from view manually In all result displays the AL label in the window title bar indicates whether
176. right at the beginning of the capture buffer you will see a Burst Not Found Message Solution Refer to Message Pattern Not Found on page 249 Switch the pattern search off Choose Burst as the reference for the result range alignment Message Pattern Not Found The Pattern Not Found error message can have several causes The burst search has failed User Manual 1176 8516 02 06 249 R amp S FPS K70 Optimizing and Troubleshooting the Measurement TE If burst and pattern search are active the application looks for patterns only within the found bursts Hence in case the burst search fails the pattern search will also fail Solution Try one of the following Make sure the burst search is successful Deactivate the burst search but keep the pattern search active For more information see Message Burst Not Found on page 247 chapter 5 7 1 Burst Search on page 164 The offset of the pattern within the burst is incorrectly set It is possible to set a pattern offset to speed up the pattern search The offset of the pattern would be the offset of the pattern start with respect to the start of the useful part of the burst However if the entered offset is not correct within about 4 sym bols of tolerance the pattern will not be found VSA Ref Level 22 00 dim Mod Modulation amp Signal Description m el Att 10 0 88 Freq 1 0GHz Cap Ler SGL TRG EXT BURST PATTERN
177. sampling period at the sample rate see Sample Rate on page 156 Note that this result display is based on an individual capture buffer range If more than 256 000 samples are captured overlapping ranges with a size of 256 000 each are created Only one range at a time can be displayed in the Frequency Absolute result display For details see chapter 4 8 Capture Buffer Display on page 122 This measurement is mainly of interest when using the MSK or FSK modulation but o can also be used for the PSK QAM modulations However since these modulations can have transitions through zero in the plane in this case you might notice uncriti cal spikes This is due to the fact that the phase of zero or a complex value close to zero is of limited significance but still influences the result of the instantaneous fre quency measurement 1 FreqAbs CaptureBuffer 1 Clrw 0 sym Fig 3 8 Result display Frequency Absolute MM User Manual 1176 8516 02 06 30 R amp S FPS K70 Measurements and Result Displays E Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow on page 359 CALC FORM FREQ to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 1 Capture Buffer Results on page 375 chapter 11 9 2 2 Cartesian Diagrams o
178. set if the sync sequence pattern of the midamble could not be detected 2to 14 Not used 15 This bit is always O 11 11 2 STATus QUEStionable MODulation lt n gt Register This register comprises information about any limit violations that may occur after demodulation any of the VSA windows It can be queried with commands STATus QUEStionable MODulation lt n gt CONDition on page 399 and STATus QUEStionable MODulation lt n gt EVENt on page 399 The status of the STATus QUESTionable MODulation register is indicated in bit 7 of the STATus QUESTionable register It can be queried using the STATus QUESTionable EVENt command Bit No Meaning 0 Error in EVM evaluation 1 Error in Phase Error evaluation 2 Error in Magnitude Error evaluation 3 Error in Carrier Frequency evaluation 4 Error in offset or RHO evaluation 5 Error in FSK evaluation 6 15 These bits are not used 11 11 3 STATus QUESTionable MODulation lt n gt EVM Register This register comprises information about limit violations in EVM evaluation It can be queried with commands Status Reporting System STATus QUEStionable MODulation lt n gt EVM CONDition STATus QUEStionable MODulation lt n gt EVM EVENt Bit No Meaning 0 Error in current RMS value 1 Error in mean RMS value 2 Error in peak RMS value 3 4 These bits are n
179. settings e poor quality in the source data false or missing sequences in the Known Data file result range alignment leads to a mismatch of the input data with the defined sequences A BER value of 0 5 means that for at least one measurement no matching sequence was found See also chapter 4 4 3 Demodulation and Symbol Decisions on page 93 2 Bit Error Rate Current Bit Error Rate 0 499 021 530 Total of Errors 510 Total of Bits 1022 The following information is provided in the BER result display Bit Error Rate error bits number of analyzed bits Total of Errors number of detected bit errors known data compared to symbol decisions Total of Bits number of analyzed bits For each of these results the following values are provided BER Result Description Current Value for current result range Minimum Minimum Current value during the current measurement Maximum Maximum Current value during the current measurement Accumulative Total value over several measurements for BER Total of Errors Total of Bits similar to average function Remote commands LAY ADD 1 BEL MACC to define the required source type see LAYout ADD WINDow on 359 CALC FORM BER to define the result type see CALCulate lt n gt FORMat on page 366 CALC BER to query the results see CALCulate lt n gt BERate on page 378 E User Manual 1176 8516 02
180. signal from the TRG AUX connector Remote command TRIG SOUR EXT TRIG SOUR EXT2 See TRIGger SEQuence SOURce on page 306 IF Power Trigger Source The R amp S FPS starts capturing data as soon as the trigger level is exceeded around the third intermediate frequency For frequency sweeps the third IF represents the start frequency The trigger band width at the third IF depends on the RBW and sweep type For measurements on a fixed frequency e g zero span or measurements the third IF represents the center frequency This trigger source is only available for RF input The available trigger levels depend on the RF attenuation and preamplification A refer ence level offset if defined is also considered Signal Capture For details on available trigger levels and trigger bandwidths see the data sheet Remote command TRIG SOUR IFP see TRIGger SEQuence SOURce on page 306 Power lt Trigger Source Triggers the measurement when the magnitude of the sampled data exceeds the trigger threshold The trigger bandwidth corresponds to the Usable Bandwidth setting for data acquisition see Usable Bandwidth on 156 Remote command TRIG SOUR see TRIGger SEQuence SOURce on page 306 Trigger Level Defines the trigger level for the specified trigger source For details on supported trigger levels see the data sheet Remote command TRIGger SEQuence LEVel
181. spectrum transformation User Manual 1176 8516 02 06 63 R amp S FPS K70 Measurement Basics poc eee ee ee ee eee If the signal is cut off increase the sample rate if it is too small decrease the sample rate by changing the Symbol Rate defined in the Signal Description settings or the Sample Rate parameter in the Data Acquisition settings As described above the sample rate is determined by the number of samples to cap ture per symbol Thus the maximum sample rate depends on the maximum number of symbols to be captured the symbol rate and vice versa The maximum sample rate for the R amp S FPS is 10 GHz see below Thus the maximum symbol rate is Table 4 1 Maximum symbol rate depending on sample rate parameter Sample rate parameter Max symbol rate 4 symbol rate 2500 MSymbols 8 symbol rate 1250 MSymbols 16 symbol rate 625 MSymbols 32 symbol rate 312 5 MSymbols 4 2 1 Sample Rate and Maximum Usable I Q Bandwidth for RF Input Definitions e Input sample rate ISR the sample rate of the useful data provided by the device connected to the input of the R amp S FPS e User Output Sample rate SR the sample rate that is defined by the user e g in the Data Aquisition dialog box in the I Q Analyzer application and which is used as the basis for analysis or output Usable Analysis bandwidth the bandwidth range in which the signal remains undistorted in regard
182. t PHASE yras t PHASE per t This measurement parameter is of great importance for MSK modulation measure ments The phase error should not be confused with the error vector phase The error vector phase is the absolute phase of the error vector see figure 4 53 The effects of the different modulation errors in the transmitter on the result display of the analyzer are described in the next topics All diagrams show the equivalent com plex baseband signal Modulation Error Ratio MER The modulation error ratio MER is closely related to EVM MER 20 log EVM dB where the EVM is normalized to the mean reference power Symbol Rate Error SRE The symbol rate error SRE describes the difference between the defined reference symbol rate and the currently measured symbol rate in relation to the reference symbol rate The value is given in parts per million ppm Signal Model Estimation and Modulation Errors SRE SR meas SR SRrer Currently the SRE is only calculated for PSK QAM and User QAM modulation and only if compensation for SRE is activated see chapter 5 9 1 Demodulation Com pensation on page 176 Example For a defined symbol rate of SRge 1 MHz and a measured symbol rate of SRweas 999 9 kHz the symbol rate error is SRE 999 9 1000 1000 1 000 000 ppm 100 ppm Offset Origin Offset Quadrature Inphase Fig 4 54 Effect of an or origin
183. that the settings of the RF attenuation and the reference level are optimally adjusted to the signal level without overloading the R amp S FPS or limiting the dynamic range by an S N ratio that is too small 11 5 2 5 Configuring VSA Usage Event INPut GAIN STATe lt State gt This command turns the preamplifier on and off If activated the input signal is amplified by 20 dB If option R amp S FPS B22 is installed the preamplifier is only active below 7 GHz If option R amp S FPS B24 is installed the preamplifier is active for all frequencies Parameters lt State gt ON OFF RST OFF Example INP GAIN STAT ON Switches on 20 dB preamplification Usage SCPI confirmed Manual operation See Preamplifier option B22 B24 on page 143 Attenuation INPUEATTORUBOF 2 21 A 294 AW TQ scu ii coros dates eut rrr aros eta sea Shades 295 ELE 295 295 edv eu v do 296 INPut ATTenuation lt Attenuation gt This command defines the total attenuation for RF input If an electronic attenuator is available and active the command defines a mechanical attenuation see INPut EATT STATe on 296 If you set the attenuation manually it is no
184. the VSA application via softkeys in the MEAS menu Restore Factory Settlhigs iced genere senn re Ege ta a grec dag aai bre Rar 129 L Restore Standard FileS csscsccsssessssscsceccececsseecetseeccseceseaccsecescaseaseeseesens 129 L Restore Pattern Files rna 129 Restore Factory Settings Opens a submenu that allows you to restore all standards and pattern settings on the instrument to the values predefined by Rohde amp Schwarz available at the time of deliv ery Restore Standard Files Restore Factory Settings Restores the standards predefined by Rohde amp Schwarz available at the time of deliv ery Note that this function will overwrite customized standards that have the same name as predefined standards Remote command SENSe DDEMod FACTory VALue 273 Restore Pattern Files Restore Factory Settings Restores the pattern files predefined by Rohde amp Schwarz available at the time of deliv ery Remote command SENSe DDEMod FACTory VALue 273 5 2 Configuration According to Digital Standards Various predefined settings files for common digital standards are provided for use with the VSA application In addition you can create your own settings files for user specific measurements Configuration According to Digital Standards For an overview of predefined standards and settings see chapter A 2 Predefined Standards and Settings on pa
185. the connector is used as an external trigger source by the R amp S FPS No further trigger parameters are available for the con nector Output The R amp S FPS sends a trigger signal to the output connector to be used by connected devices Further trigger parameters are available for the connector Remote command OUTPut TRIGger lt port gt LEVel on page 289 OUTPut TRIGger port DIRection on page 289 Output Type Trigger 2 Type of signal to be sent to the output Device Trig Default Sends a trigger when the R amp S FPS triggers gered Trigger Sends a high level trigger when the R amp S FPS is in Ready for trig Armed ger state This state is indicated by a status bit in the STATus OPERation reg ister bit 5 User Defined Sends a trigger when user selects Send Trigger button In this case further parameters are available for the output signal Remote command OUTPut TRIGger port OTYPe on page 290 Level Output Type Trigger 2 Defines whether a constant high 1 or low 0 signal is sent to the output connector Remote command OUTPut TRIGger lt port gt LEVel on page 289 Pulse Length Output Type Trigger 2 Defines the length of the pulse sent as a trigger to the output connector Remote command OUTPut TRIGger lt port gt PULSe LENGth on page 290 Send Trigger Output Type Trigger 2 Sends a user defined trigger to the output connector immediately Note that the t
186. the scrollbar beneath the input area The number beneath the scrollbar at the right end indi cates the sequential number of the last symbol field the number in the center indicates the sequential number of the currently selected symbol field To remove a symbol field select it and press Remove 7 Select Save to save the pattern under the specified name The pattern is stored on the instrument as an xml file named Name xm1 under Installation directory gt vsa Pattern If you copy this file to another location you can restore the pattern at a later time e g after deletion Example Defining a pattern KUM x Name TETRA_SA Symbols Format Binary Hex Decimal E Remove LE 1 12 16 Comment Fig 8 1 Pattern definition How to Perform Customized Measurements 8 2 2 How to Manage Patterns To change the display for the list of patterns 1 In the Overview select Signal Description and switch to the Signal Structure tab 2 Select Pattern Config to display the Advanced Pattern Settings dialog box 3 To display all available patterns select Show All To display all patterns that are compatible to the defined standard select Show Compatible To display only patterns that contain a specific prefix enter the Prefix in the edit field To edit a predefined pattern 1 In the Overview select Signal Description and switch to t
187. the trigger settings or increase the result length Note however that in this case the results are actually correct and the message can be ignored e The settings do not match the signal In order to allow you to select certain bursts the burst search only searches for bursts that have a length between Min Length and Max Length plus a tolerance that you can set in the Burst Search Dialog In case the burst is e g shorter than the Burst Min Length the burst search fails Mag CapBuf I 3 Modulation amp Signal Description Modulation Signal Description Signal Type Continuous Signal Burst Signal Burst Min Length 738 462 Max Length 300 sym 21 108 m Start 0 sym Ll 1300 sym _ Run In S sym 11 077 Gsym _______ 11 077 Fig 10 5 Example a failed burst search due too a burst that is too short mum PEINE DRAN EN V US User Manual 1176 8516 02 06 248 R amp S FPS K70 Optimizing and Troubleshooting the Measurement TE Solution try one of the following Switch on the Magnitude Capture Buffer result display Move a marker to the start of the burst Move a delta marker to the end of the burst and compare the burst length to the settings in the Signal Description dialog Increase the search tolerance in the Burst Search dialog Keep an eye on the green red field If the burst search succeeds you can see the length of the found bursts Set th
188. the x axis and y axis to the current measurement values only once not dynamically in all measurement windows Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO ALL on page 330 Trace Settings 6 Analysis General result analysis settings concerning the trace markers windows etc can be configured via the Analysis button in the Overview They are identical to the analy sis functions in the base unit except for the special window functions Window specific configuration o The settings in the Analysis dialog box are specific to the selected window Thus the Analysis button is only available in the Overview if the Specifics for option is enabled To configure the settings for a different VSA window select the window out side the displayed dialog box or select the window from the Specifics for selection list in the dialog box e race ERROR REN NEEKERAARMARRMINMISRRRKR NUMEN RSEN 190 uo edd E 193 MaKe ee M 194 e Modulation Accuracy Limit LI es ceo er t Fen erre tenete cs 199 e Display and Window Configuration ssssssseeeeeeenne 201 ZOOM FUNTON S ai 204 6 1 Trace Settings The trace settings determine how the measured data is analyzed and displayed in the window Depending on the result display b
189. to amplitude characteristic and group delay this range can be used for accurate analysis by the R amp S FPS Record length Number of I Q samples to capture during the specified measure ment time calculated as the measurement time multiplied by the sample rate For the data acquisition digital decimation filters are used internally in the R amp S FPS The passband of these digital filters determines the maximum usable bandwidth In consequence signals within the usable bandwidth passband remain unchanged while signals outside the usable I Q bandwidth passband are suppressed Usually the suppressed signals are noise artifacts and the second IF side band If frequencies of interest to you are also suppressed you should try to increase the output sample rate since this increases the maximum usable band width Bandwidth extension options 5 The maximum usable bandwidth provided by the R amp S FPS in the basic installation can be extended by additional options These options can either be included in the ini tial installation B options or updated later U options The maximum bandwidth provi ded by the individual option is indicated by its number for example B40 extends the bandwidth to 40 MHz User Manual 1176 8516 02 06 64 _ Sample Rate Symbol Rate and Bandwidth As a rule the usable bandwidth is proportional to the output sample rate Yet when the bandwidth reaches the
190. to the VSA application are descri bed For details on the common R amp S FPS status registers refer to the description of remote control basics in the R amp S FPS User Manual Status Reporting System o RST does not influence the status registers Description of the Status Registers In addition to the registers provided by the base system the following registers are used in the VSA application STATus QUEStionable SYNC lt n gt contains application specific information about synchronization errors or errors during burst detection STATus QUESTionable MODulation lt n gt provides information any limit violations that occur after demodulation in one of the 4 windows STATus QUESTionable MODulation lt n gt EVM limit violations in EVM evalua tion STATus QUESTionable MODulation lt n gt PHASe limit violations in Phase Error evaluation STATus QUESTionable MODulation lt n gt MAGnitude limit violations in Mag nitude Error evaluation STATus QUESTionable MODulation lt n gt CFRequency limit violations in Car rier Frequency evaluation STATus QUESTionable MODulation lt n gt IQRHO limit violations in and RHO evaluation STATus QUESTionable MODulation lt n gt FSK limit violations in FSK evalua tion e g bit 11 sums up the information for all STATus QUEStionable SYNC registers For some subregisters there may be separate registers
191. to the reference marker or the fixed reference Example INIT CONT OFF Switches to single sweep mode INIT WAI Starts a sweep and waits for its end CALC DELT2 ON Switches on delta marker 2 CALC DELT2 Y Outputs measurement value of delta marker 2 Usage Query only Analysis 11 7 2 2 Marker Search and Positioning Settings Several functions are available to set the marker to a specific position very quickly and easily In order to determine the required marker position searches may be performed The search results can be influenced by special settings Useful commands for positioning markers described elsewhere CALCulate lt n gt MARKer lt m gt TRACe on page 341 CALCulate lt n gt DELTamarker lt m gt TRACe on page 343 Remote commands exclusive to positioning markers lt gt lt gt 344 CAL Culat lt n gt DEL Tamarkersmo MAXIm tm LEP necatta 344 lt gt lt gt 345 lt gt lt gt 41 4 345 lt gt lt gt 345 lt gt lt gt
192. to your specific requirements e Configuring the measurement settings and if necessary storing the settings in a file How to Perform VSA According to Digital 210 e How to Perform Customized VSA 212 e Howto Analyze the Measured 022 44 1 12 221 8 1 How to Perform VSA According to Digital Standards In order to perform vector signal analysis as specified in digital standards various pre defined settings files for common digital standards are provided for use with the option In addition you can create your own settings files for user specific measure ments For an overview of predefined standards and settings see chapter A 2 Predefined Standards and Settings on page 412 This section provides instructions for the following tasks To perform a measurement according to a standard on page 210 Toload predefined settings files on page 211 e To store settings as a standard file on page 211 To delete standard files on page 211 Torestore standard files on page 212 To perform a measurement according to a standard 1 Press the MODE key and select the VSA application 2 Press the MEAS key and select the Digital Standards softkey 3 Select the required settings file and then Load see To load predefined settings files on page 211
193. width Usage Query only Manual operation See Usable Bandwidth on page 156 Triggering Measurements The trigger commands define the beginning of a measurement MSRA operating mode In MSRA operating mode only the MSRA Master channel actually captures data from the input signal Thus no trigger settings are available in the VSA application in MSRA operating mode However a capture offset can be defined with a similar effect as a trigger offset It defines an offset from the start of the captured data from the MSRA Master to the start of the application data for vector signal analysis See Configuring an Analysis Interval and Line MSRA mode only For details on the MSRA operating mode see the R amp S FPS MSRA User Manual Tasks for manual configuration are described in chapter 5 6 2 Trigger Settings on page 157 TRIGE SEQuencelDTIMg nei ex nente 304 TRIG er SEQuence 304 TRIGger SEQueneebIFPowetrEOLDolf 2 1 rtt 304 TRIGger SEQuence IFPower HYSTeresis eene mene 304 TRIGger SEQuenceJ LEVel EXTernal port cessere 305 TRiGger SEQuence LEV ell FPOW GR uad tuna onte pt ttd de 305 TRIGger SEQuence LEVel IQOoWer ainar 305 SEQuence SL
194. with a corresponding command Querying numeric values When you query numeric values the system returns a number In case of physical quantities it applies the basic unit e g Hz in case of frequencies The number of dig its after the decimal point depends on the type of numeric value Example Setting SENSe FREQuency CENTer 1GHZ Query SENSe FREQuency CENTer would return 1E9 In some cases numeric values may be returned as text e INF NINF Infinity or negative infinity Represents the numeric values 9 9E37 or 9 9E37 Not a number Represents the numeric value 9 91E37 is returned in case of errors Boolean Boolean parameters represent two states The ON state logically true is represen ted by ON or a numeric value 1 The OFF state logically untrue is represented by OFF or the numeric value 0 Querying boolean parameters When you query boolean parameters the system returns either the value 1 ON or the value 0 OFF Example Setting DISPlay WINDow ZOOM STATe ON Query DISPlay WINDow ZOOM STATe would return 1 Character Data Character data follows the syntactic rules of keywords You can enter text using a short or a long form For more information see chapter 11 1 2 Long and Short Form on page 266 Querying text parameters When you query text parameters the system returns its short form Common Suffixes Example Setting SEN
195. 0 0011101 0010010 0010011 0010111 0010110 0011110 0011111 0000010 0000011 0000111 0000110 0001110 0001111 0000000 0000001 0000101 0000100 0001100 0001101 Fig 4 35 Constellation diagram for 128QAM including the logical symbol mapping hexadecimal and binary the figure shows the upper right sections of the diagram only Fig 4 36 Constellation diagram for 256QAM including the logical symbol mapping hexadecimal the figure shows the upper right section of the diagram only Symbol Mapping 726 o7 05 018 012 010 07A 078 072 070 01A 073 071 01B 019 013 011 07B 079 1 01D 017 05 07 07D 077 01E 01C 016 014 07 07 076 074 5 7 Fig 4 37 Constellation diagram for 512QAM including the logical symbol mapping hexadecimal the figure shows the upper right section of the diagram only He 8 Be Be Ee Ee Ze Eo Jo Fe Fe Fo Fe Ge He Be Be de Fo Fe Fo Go Fo Ge Be ge Se Ge Ze Ze Ze Ge de Ze Yo Se Bo Go Yo Go e Se He Ee Ze De Ze de de Bo Ho fe 59 Ge Be Ge Fe Fe Jogo Ee Eo Be Ge Bo de Ue fogo Se Be Se Ze He 8 Uo Be He be de He He de Ho he De Be ge de Yo pe de fo Se De De De Be
196. 00 R amp S FPS K70 Remote Commands for VSA STATus QUEStionable LIMit lt m gt NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable LMARgin lt m gt NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt NTRansition BitDefinition lt ChannelName gt STATus QUEStionable MODulation lt n gt CFRequency NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt EVM NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt FSK NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt IQRHo NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt MAGNitude NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt PHASe NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable POWer NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable SYNC NTRansition lt BitDefinition gt lt ChannelName gt This command controls the Negative TRansition part of a register Setting a bit causes a 1 to 0 transition in the corresponding bit of the associated regis ter The transition also writes a 1 into the associated bit of the corresponding EVENt register Parameters lt BitDefinition gt Range 0 to 65535 lt ChannelName gt String containing the name of the channel Th
197. 02 Wvo4esn cS ES MS ye1 OW cS _ eumde 06 Seo ZHIN Oc 5 8 ZS 25 I ouo dd Load N amp injeN 5 eumde 193 40 MSINO ZHW ZSV MSdc zed 1038 _ 44 1030 Old dd 1930 9UON apax GZ 662 0 eumde dd 1930 40 MSINO ZHW 291 MSdc 1038 5 9UON GL LYE 09 01415118 9 6 40 MSINO ZHIN MSdc enig u16ue sang 19114 9je1 Buiddew 1426 10 104 6 puepuejs Japjo4 Predefined Standards and Settings s ous e Jo pJepueis SJOYIP eeuw si Jo 425 991 x WL yis 5 5 338 0 ysung 000 euis ZHN SHO OIZ D 009 INSL6 19 ue2 SUON 33g 0 ysung 000L 0L ZH 009 sdg 912 wiayed ysung Joy ayes Buiddew 1426 ynsey ulayed 10 youeag 20 yoseas 1g eudiv joquiAg uonejnpow _
198. 06 21 R amp S9FPS K70 Measurements and Result Displays 3 2 2 3 2 3 Channel Frequency Response Group Delay The Frequency Response Group Delay of the channel is the derivation of phase over frequency for the original input signal It is measure of phase distortion 4 ChanGroupDelay Equalizer Start 100 MHz Stop 100 MHz Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow page 359 CALC FEED XFR DDEM IRAT to define the channel frequency response result type see CALCulate lt n gt FEED on page 365 CALC FORM GDEL to define the group delay result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 6 Equalizer on page 377 Channel Frequency Response Magnitude The frequency response magnitude of the channel indicates which distortions occurred during transmission of the input signal It is only determined if the equalizer is activa ted SSS Ee a User Manual 1176 8516 02 06 22 R amp S FPS K70 Measurements and Result Displays 2 ChanFreqResp Equalizer ei Clrw Start 100 MHz Stop 100 MHz The bandwidth for which the channel transfer function can be estimated is not only limi ted by the usable bandwidth but also by the bandwidth of the analyzed input sig nal Areas with low recep
199. 0S1 WvoOZ adeys esind 3903 usu wv 5224 Y 0 241 YSH 3903 3903 ZH SZE 926 022 3903 ME asing LOSL WvOZ 3903 3903 esind edeus jeje 0051 WvoZz asind 8908 usu wv S 7A4L v 0 241 3904 3903 ZH SZE 926 022 3903 Joy Buidde y 1829 u16ue sang 19114 9je1 10 JoquiAs uone npo N puepuejs Jopjo4 Predefined Standards and Settings s ous e Jo OU SJOYIP si 425 991 x 191092 ROOM IN Gig yoo 8 7982 Z 01jsung 0 82 90 MSINS ZHN ASAZ enig SUON IN yoo 97619 Z 01jsung 2294 90 MSINS ZHN ASAZ enig 19082 SUON IN g 9 Z 01jsung 99 90 ASNS ZHW ujoojenig 2 eseud Sc _ 08 3NON ZH 9 MSdv Zd OOdV 2 eseud oDueiJ 191 Ndo 92 INQO H 89 H S ZOOdV ZH 9 MSdv Zd OOdV 82094
200. 1 1 2 1 2 Example Element order for complex cartesian data 1 channel I 0 0101 Real and imaginary part of complex sample 0 I 1 0111 Real and imaginary part of complex sample 1 1 2 0121 Real and imaginary part of complex sample 2 Example Element order for complex polar data 1 channel Mag 0 Phi 0 Magnitude and phase part of complex sample 0 Mag 1 1 Magnitude and phase part of complex sample 1 Mag 2 Phi 2 Magnitude and phase part of complex sample 2 Example Element order for complex cartesian data 3 channels Complex data I channel no time index Q channel index 01101 0101101 Channel 0 Complex sample 0 11101 0111101 Channel 1 Complex sample 0 21101 0121101 Channel 2 Complex sample 0 01111 0101111 Channel 0 Complex sample 1 11111 0111111 Channel 1 Complex sample 1 21121 Channel 2 Complex sample 1 01121 0101121 Channel 0 Complex sample 2 11191 Peay Channel 1 Complex sample 2 21121 0121121 Channel 2 Complex sample 2 Example Element order for complex cartesian data 1 channel This example demonstrates how to store complex cartesian data in float32 format using MATLABS Save vector of complex cartesian I Q data i e iqiqiq N 100 iq randn 1 N 1j randn 1 N fid fopen xyz complex float32 w for k 1 length iq fwrite fi
201. 136 SENSe DDEMod MAPPing CATalog This command queries the names of all mappings that are available for the current modulation type and order A mapping describes the assignment of constellation points to symbols Return values lt Mappings gt A comma separated list of strings with one string for each map ping name Example SENSe DDEMod MAPPing CATalog Result CDMA2K FWD DVB S2 GRAY NATURAL WCDMA Example See chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Usage Query only Manual operation See Modulation Mapping on page 137 SENSe DDEMod MAPPing VALue Mapping To obtain a list of available symbol mappings for the current modulation type use the SENSe DDEMod MAPPing CATalog query Configuring VSA Setting parameters Mapping string Example SENS DDEM MAPP GSM Sets mapping to GSM Example See chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Modulation Mapping on page 137 SENSe DDEMod MSK FORMat lt MSKformat gt This command defines the specific demodulation order for MSK Setting parameters lt MSKformat gt TYPE1 T
202. 153 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe Range This command defines the display range of the y axis for all traces lt t gt is irrelevant Example DISP TRAC Y 110dB Usage SCPI confirmed DISPlay WINDow lt n gt TRACe lt t gt Y SCALe PDIVision Value This remote command determines the grid spacing on the Y axis for all diagrams where possible The suffix lt t gt is irrelevant Configuring VSA Parameters Value numeric value WITHOUT UNIT unit according to the result dis play Defines the range per division total range 10 lt gt RST depends on the result display Example DISP TRAC Y PDIV 10 Sets the grid spacing to 10 units e g dB per division Manual operation See Range per Division on page 152 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RPOSition Position This command defines the vertical position of the reference level on the display grid for all traces t is irrelevant The R amp S FPS adjusts the scaling of the y axis accordingly Example DISP TRAC Y RPOS 50PCT Usage SCPI confirmed Manual operation See Y Axis Reference Position on page 152 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RVALue Value The command defines the power value assigned to the reference position in the grid for all traces t is irrelevant For external generator calibration measurements requires the optional External Gen erator Control this co
203. 171 SCANS 171 Seale la 171 Meas only if Pattern Symbols Comect iio 171 Standard Patterns selecting an assigned pattern The Standard Patterns are the patterns assigned to the currently selected standard You can add existing patterns to the standard or remove patterns already assigned to the standard The highlighted pattern is currently selected for pattern search Remote command SENSe DDEMod SEARch SYNC SELect on page 312 Burst and Pattern Configuration Removing patterns from a standard Removes the assignment of the selected patterns to the standard The patterns are removed from the Standard Patterns list but not deleted Remote command SENSe DDEMod SEARch SYNC PATTern REMove on page 315 Adding patterns to a standard Adds the selected patterns in the list of available patterns Patterns to the list of assigned patterns Standard Patterns For details see To add a predefined pattern to a standard on page 214 Remote command SENSe DDEMod SEARch SYNC PATTern ADD on page 315 Displaying available patterns The All Patterns list contains the patterns available in the VSA application You can assign available patterns to the selected standard edit existing or define new patterns For details on managing standard patterns see ch
204. 2 lt float gt lt float gt 140 lt float gt lt ArrayOfFloat gt lt Min gt lt Max gt lt ArrayOfFloat length 256 gt lt float gt 70 lt float gt lt float gt 71 lt float gt float 69 float ArrayOfFloat lt gt PowerVsTime Spectrum Min ArrayOfFloat length 256 gt lt float gt 133 lt float gt lt float gt 111 lt float gt lt float gt 111 lt float gt lt ArrayOfFloat gt lt Min gt lt Max gt lt ArrayOfFloat length 256 gt float 67 float lt float gt 69 lt float gt lt float gt 70 lt float gt lt float gt 69 lt float gt lt ArrayOfFloat gt lt Max gt lt Spectrum gt IQ Histogram width 64 height 64 gt 0123456789 0 lt Histogram gt IQ lt Channel gt lt ArrayOfChannel gt lt PreviewData gt 7 2 Data Binary File The data is saved in binary format according to the format and data type specified in the XML file see Format element and DataType element To allow reading and writing of streamed data all data is interleaved i e complex values are interleaved pairs of and Q values and multi channel signals contain interleaved complex sam Data File Format iq tar ples for channel 0 channel 1 channel 2 etc If the NumberOfChannels element is not defined one channel is presumed Example Element order for real data 1 channel I 0 Real sample 0 Real sample
205. 3 kHz 4 5 2 1 Error Model The FSK measurement model used assumes that signal distortions in both the magni tude and phase frequency are present as well as additive noise The measured signal model is expressed as MEAS t Apysr t ef Pons n t with n t is a disturbing additive noise process of unknown power Apisr t is the distorted magnitude model and q 5T0 is the distorted phase model The magnitude model is given by Apre with K is a constant scaling factor which can be interpreted as the system gain and is the amplitude droop in Nepers per second The phase model is given by Signal Model Estimation and Modulation Errors Prep 6 0 Ct V D with B is a scaling factor which results in a reference deviation error C is a carrier frequency offset in radians per second D is a frequency drift in radians per second per second Tis a timing offset in seconds and is a phase offset in radians For the above phase model an equivalent frequency distortion model may be expressed as fosr B fage t 0 fo fat with B is the scaling factor which results in a reference deviation error 2 is a carrier frequency offset in Hz 0 2 is a frequency drift in Hz per second and ris the timing offset in seconds The measured signal model in terms of the instantaneous frequency and all distortion parameters is given by t foa
206. 5 Wrap result type tesise 44 Phase error Definition Formula 425 Result type 43 RMS peak formulae 428 Phase Error type unire ret c 44 Phase shift keying See e M 68 Phase unwrap Unwrap resull type etaed 45 Preamplifier SEWING x cene alien 143 149 Softkey Prefix Patten pee 170 Presetting Channels nete terrre re nr 133 Default values 128 Pretrigge 160 Programming examples Burst GSM EDGE signal Continuous QPSK signal Protection RE input Femole nee reete 288 PSK Differential ied ie 73 Error model 100 Mixed TOMS c 74 Modulation type 185 Rotating nee 511 Rotating differential 2 74 Symbol MAPPING 68 Q QAM Ertormodel tnde a 100 Modulation oi esto ni nett eerie 135 xoci tin teeth Lr entre ei eats 80 QPSK Measurement example did Y 75 Offset symbol mapping 75 Programming example nocte entia 404 Quadrature Amplitude Modulation sea QAM nudus sq 80 Quadrature error arsi Ee
207. 64 64 bit floating point data IEEE 754 Data File Format iq tar Element Description ScalingFactor Optional describes how the binary data can be transformed into values in the unit Volt The binary data itself has no unit To get an sample in the unit Volt the saved samples have to be multiplied by the value of the ScalingFactor For polar data only the magnitude value has to be multiplied For multi channel signals the ScalingFactor must be applied to all channels The attribute unit must be set to v The ScalingFactor must be gt 0 If the ScalingFactor element is not defined a value of 1 V is assumed NumberOfChan Optional specifies the number of channels e g of a MIMO signal contained in the nels data binary file For multi channels the samples of the channels are expected to be interleaved within the data file see chapter A 7 2 Data Binary File on page 443 If the NumberOfChannels element is not defined one channel is assumed DataFilename Contains the filename of the 1 data binary file that is part of the iq tar file It is recommended that the filename uses the following convention lt xyz gt lt Format gt lt Channels gt ch lt Type gt xyz a valid Windows file name e Format complex polar or real see Format element e Channels Number of channels see NumberOfChannels element e Type float32 float64 int8 int16 int32 or
208. 8 Settings predefined 192 Symbols remote 9 6 eria ne re nes 255 eret rome ia tne envie 58 Alpha BT nf s tecto e tage 419 tenter ioni iei Dri vt Unde User defined Using as measurement filter Trigger Configuration Drop out time External 2 2 ene erts 306 s onte rt cene Cn 161 aii e 160 160 OUTPUT 144 Remote 303 Slope 161 306 Trigger l amp Vel cerent ner re mne 160 External trigger 305 Power remote IF Power remote Trigger SOURCE termin External Free Run Power OU d eu od Triggers M Troubleshooting SOarcli d Eterna 246 244 Frequently asked questions 255 liput overload 2 eter teet ttes 288 Pattern search eed ens 246 Result display 255 Mc ETE 255 U Units Reference level 1 iie asia ci cea tn nna era 148 X axis X axis y axis bcol
209. 9 5 70 Measurement Basics p M P e qe rums n Derivation of OQPSK Table 4 11 diagram and constellation diagram QPSK OQPSK delayed Q component Inphase Quadratu re Quadratur e 4 66 M symbols symbols PSK vector diagram with alpha 0 35 OQPSK vector diagram with alpha 0 35 2 Quadrature Quadrature Inphase Inphase Offset QPSK reduces the dynamic range of the modulated signal with respect to nor mal QPSK and therefore the demands on amplifier linearity by avoiding zero cross ings A distinction is made in the analyzer display In the Vector result display of the measurement or reference signal the time delay is not compensated for The display corresponds to the physical diagram shown in table 4 11 In the Constellation result display of the measurement or reference signal the time delay is compensated for The display corresponds to the logical mapping as in figure 4 22 pum EIN NDA CN V UU User Manual 1176 8516 02 06 76 4 3 6 Symbol Mapping OQPSK Fig 4 22 Constellation diagram for OQSK GRAY including the symbol mapping Frequency Shift Keying FSK To illustrate symbol mappings for FSK modulations the symbol numbers are marked in the logical mapping diagram versus the instantaneous frequency An insta
210. Alignment LEFT CENTer RIGHt LEFT The reference point is at the start of the result range CENTer The reference point is in the middle of the result range RIGHt The reference point is displayed at the end of the result range RST LEFT Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Alignment on page 175 CALCulate lt n gt TRACe lt t gt ADJust ALIGnment OFFSet FitOffset This command shifts the display range relative to the reference time by the number of given symbols The resolution is 1 symbol A value gt 0 results in a shift towards the right and a value lt 0 results in a shift towards the left Suffix lt gt 1 6 Setting parameters lt FitOffset gt numeric value Range 8000 to 8000 RST 0 Default unit SYM Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Offset on page 175 Configuring VSA CALCulate n TRACe t ADJust VALue Reference This command defines the reference point for the display Suffix lt gt 1 6 Setting parameters Reference TRIGger BURSt PATTern TRIGger The reference point is defined by the start of the capture buffer BURSt The reference point is defined by the start center end of the burst PATTern The instrument selects the reference point a
211. Automatic Config ratiOn erre erc 188 Configuration remote 329 Averaging Measurements 165 168 171 B Bandwidth Coverage MSRA mode 124 58 Extension options 64 65 tenter aret rr Roc 64 Relationship to sample rate 65 Signal processing 5 Usable MaX E 64 Bit error rate BER IRA 20 Burst GSM EDGE Measurement example nennen 235 Burst search ceste te ri Deren 92 AUTO 166 COMMOTION hints 164 Demodulation process as E Is een mc Parameters ae PROCCSS i REMOTE FRODUSIMESS T 91 Tolerance 166 139 Bursts DIE ET T2 Length min max eene 140 Programming example nono erinnern 405 Reference for result range 174 PROM SUN 140 Once 140 io 119 C Capture buffer Data e 15 Display 122 116 Navigating S 233 Ref
212. Available for source types e Modulation Errors Remote commands LAY ADD 1 BEL MERR to define the required source type see LAYout ADD WINDow 2 page 359 CALC FORM PHAS to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 3 2 26 Phase Wrap The phase or argument of the signal the display is limited to the phase value range of 180 180 Phase yras Z MEAS t with and Tp the duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 Available for source types e Meas amp Ref Signal User Manual 1176 8516 02 06 44 R amp S FPS K70 Measurements and Result Displays mm EE SSS E um 1 PhaseWrap Meas amp Ref 1M Clrw 49 sym Fig 3 17 Result display Phase Wrap Remote commands LAY ADD 1 BEL REE to define the required source type see LAYout ADD WINDow 2 page 359 CALC FORM PHASe to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 3 2 27 Phase Unwrap The phase of the signal the display
213. BEMGOG PSKI FORMAL 222 orco ended rue aoo coit e 280 ISENSeJDDEMOd PSR NS Tale ete e edo Pe Fence Da dee 281 SENSeDDEMOod QAM FORMAlt 2 rue ntt tt eta ener ta RE 281 SENSe DDBEMed QAM NSTale treten eoecr rece v epa ed S 281 ISENSe IDDEMOdX OPSETORMAL e ren nex checa eec vare cu 282 E 282 283 SENSe DDEMod T EIEter NAME eiae teo co eae acce Pone 283 SENSe DDEMod TFILter S TATe cec tette 283 ISENSe DDEModg TFILtet USE ide tur tier ree er rena ot Cem er t metrum 284 esee cos 284 CALCulate lt n gt FSK DEViation REFerence RELative FSKRefDev This command defines the deviation to the reference frequency for FSK modulation as a multiple of the symbol rate For details see FSK Ref Deviation FSK only on page 137 Configuring VSA Setting parameters lt FSKRefDev gt numeric value Range 0 1 to 15 RST 1 Default unit NONE Manual operation See FSK Ref De
214. CALCulate n STATistics SCALe X BCOunt caecis eene n nnn 297 lt gt 5 5 297 CALCulatesms STATistics SCALe YS UPP er uia iat ctr ttt o reat er cb eaae ea 297 CALCulatesn STATisties SCALE e eerie Tasa 298 GALOCulate n UNIT ANGbLe i ion e rns 298 2 22 0 298 Y UNITS TIME Te sud n 298 9 lt gt lt gt 299 DISPlay WINDow n TRACe t X SCALe RPOSition seen 299 DISPlay WINDow n TRACec t X SCALe RVALue cesses 299 DISPlay WINDow n TRAGCest Y SCALe 22iiiiiccnini ze cie na n eeu aa 299 8 lt gt lt gt 0 299 DISPlay WINDow n TRACe t Y SCALe RPOSition seen 300 DISPlay WINDow n TRACe t Y SCALe RVALue eese 300 DISPlay WINDow n TRACe t Y SPACing eese
215. Culate lt n gt LIMit MACCuracy DEFault Restores the default limits and deactivates all checks in all windows Usage Event Manual operation See Set to Default on page 200 CALCulate lt n gt LIMit MACCuracy STATe lt LimitState gt Limits checks for all evaluations based on modulation accuracy e g Result Summary are enabled or disabled Setting parameters lt LimitState gt ON OFF 1 0 RST 0 Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Checking Modulation Accuracy Limits on page 200 R amp S FPS K70 Remote Commands for VSA I lt lt 11 7 3 2 Defining Limits The following commands are required to define limits for specific results CALCulate lt n gt LIMit MACCuracy CFERror CURRent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy CFERror MEAN STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy CFERror PEAK STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy EVM PCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy EVM PMEan STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy EVM PPEak STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy EVM RCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy EVM RMEan STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy EVM RPEak
216. DEMod SEARch BURSt SKIP FALLing on page 285 Pattern Settings If the signal is expected to have a specific pattern enable the Pattern option to define the pattern settings Note The pattern search itself must be enabled separately in the Pattern Search Set tings see Enabling Pattern Searches on page 167 By default the pattern search is active if the signal description contains a pattern Name lt Pattern Settings Specifies the pattern name from the list of defined patterns You can also configure new patterns see chapter 5 7 3 Pattern Configuration on page 168 Remote command SENSe DDEMod SIGNal PATTern on page 286 Pattern Configuration Pattern Settings Displays the Pattern Configuration dialog box see chapter 5 7 3 Pattern Configura tion on page 168 Signal Description Offset Pattern Settings The offset of the pattern is defined with respect to the start of the useful part of the burst see Useful length on page 119 If the position of the pattern within the burst is known it is recommended that you define the offset That will accelerate the pattern search and enhance the accuracy of the burst search Remote command SENSe DDEMod STANdard SYNC OFFSet STATe on page 287 SENSe DDEMod STANdard SYNC OFFSet VALue on page 287 5 4 3 Known Data The Known Data settings allow you to load a file that describes the possible data sequences in the input signal See chap
217. EAEE Definition tere eec Max usable bandwidth MAXIMUM eve ead terat ia Dese io ey Relationship to bandwidth Relationship to symbol rate 64 REMO ote 301 SEN AA 156 Saving Selllligs cm b crei Deseo ote br e ate s 131 Scaling Automatically ertet 151 189 Diagrams Changing tne 223 AXIS eie terii 150 224 X axis automatically iiis 153 X axis y axis default sss 153 Y AXIS 150 223 224 Y axis remote control sees 300 Y axis statistics oec eret rete itt 152 Search Direction Real or Imag Tolerance Burst Search Search limits ACUValITIg 22 mn tae ea d ree CORN 197 Secure user mode Storage oi ett reni ees 130 Select Result Rng Softkey Sequencer Aborting remote Activating remote Mode remote e mie ten ROMO ER Settings Imus 130 Restoring 166 129 131 Storage loCallO i ion eter cci nnb e e nde 130 Settings files Deleting 131 Loading ps Saving Sighal Capture oir trt et Etre tinens 154 control renes 301 Signal description Configuration Configuration remote site
218. EIA IS 95 A May 1995 and CDMA2000 1X forward link http www 3gpp2 org Public_html specs C S0002 C_v1 0 pdf 28 05 2002 CDMA2000 1X Reverse Filter for CDMA ONE forward link TIA EIA IS 95 A May 1995 and CDMA2000 1X reverse link http www 3gpp2 org Public_html specs C S0002 C_v1 0 pdf 28 05 2002 Rectangular Rectangular filter in the time domain with a length of 1 symbol period None USER No filter is used User defined filter Define the filter using the SENSe DDEMod TFILter USER command A 3 2 Measurement Filters Predefined Measurement and Tx Filters The most frequently required measurement filters are predefined in the VSA applica tion Table 1 3 Overview of predefined measurement filters EDGE NSR Measurement filter required for the EDGE Normal Symbol Rate standard see 3GPP TS 45 005 chapter 4 6 Modulation Accuracy The resulting system is NOT inter symbol interfer ence free EDGE HSR Narrow Pulse Measurement filter required for the EDGE High Symbol Rate Narrow Pulse standard EDGE HSR Wide Pulse Measurement filter required for the EDGE High Symbol Rate Wide Pulse standard Gauss Classic Gauss filter with an adjustable BT Low ISI Meas Filter Measurement filter implemented to retain a low intersymbol inferference Best suited for eye diagrams or 1 vector dia grams Not necessarily suited for EVM evaluation due to amplifi
219. EQuence SLOPe on page 306 Trigger Holdoff Defines the minimum time in seconds that must pass between two trigger events Trigger events that occur during the holdoff time are ignored Remote command TRIGger SEQuence IFPower HOLDoff on page 304 Capture Offset This setting is only available for applications in MSRA operating mode It has a similar effect as the trigger offset in other measurements it defines the time offset between the capture buffer start and the start of the extracted application data In MSRA mode the offset must be a positive value as the capture buffer starts at the trigger time 0 Remote command SENSe MSRA CAPTure OFFSet on page 355 Sweep Settings The sweep settings define how often data from the input signal is acquired and then evaluated They are configured via the SWEEP key Continuous Sweep RUN GONT eade reci etri ener edes 161 Single Sweep RUN 162 Continue Single 162 Refresh homaMultistandard Ode is etr rd ein 162 Statiste 162 CIOCE RESUME PRG TERR 163 oec oai 163 Continuous Sweep RUN CONT After triggering starts the measurement and repeats it continuously until stopped While the measurement is running the Continuous Sweep softkey and the RUN CONT key are
220. Filters on page 59 The Measurement Filter settings are displayed when you do one of the following e Select the Measurement Filter button from the Overview e Select Demod Meas Filter softkey from the main VSA menu Then switch to the Meas Filter tab A live preview of the constellation with the current settings is displayed in the preview area at the bottom of the dialog box The preview area is not editable directly m Demodulation amp Measurement Filter Demodulation Demodulation Advanced Meas Filter Measurement Filter Auto according to Transmit Filter Type RRC la Alpha BT 0 22 e Preview Preview Constellation I Q Meas amp Ref 1M Clrw Start 2 794 Stop 2 794 L Load User FIO eA 186 ED e a a e a RUNE 186 SSE SS User Manual 1176 8516 02 06 185 Measurement Filter Settings Using the Transmit Filter as a Measurement Filter Auto If the Auto option is enabled the measurement filter is defined automatically depend ing on the transmit filter specified in the Modulation settings see Transmit Filter Type on page 138 Note If a user defined transmit filter is selected and the measurement filter is defined automatically a Low ISI measurement filter according to the selected user filter is cal culated and used Remote command SENSe DDEMod MFILter AUTO on page 327 Type Defines the measurement filter type if the Using the Transmit Filter as a Measure
221. Hz Swap I Q Preview Mag CaptureBuffer 0 8000 sym User Manual 1176 8516 02 06 155 Signal Capture MSRA operating mode In MSRA operating mode only the MSRA Master channel actually captures data from the input signal The data acquisition settings for the VSA application in MSRA mode define the application data extract and analysis interval For details on the MSRA operating mode see the R amp S FPS MSRA User Manual Capture Length 156 Sample T5816 AE SERRE HE ER ER a ER RE pr deca 156 Usable WO BandWwWidth rtr rn n d a nnn IRR nnde 156 Pee 157 Capture Length Settings The capture length defines how many symbols are captured during each measure ment Enable the Auto option to define the capture length automatically according to the burst and pattern length settings and the statistics count Thus a minimal capture length is used which improves performance If the capture length is not defined automatically enter the number of symbols or sec onds to be captured and select the used unit The defined number is converted to the alternative unit seconds symbols for reference As of firmware version 1 70 up to 64000 symbols can be captured and processed dur ing each measurement previously 50000 Remote command SENSe DDEMod RLENgth AUTO on page 302 SENSe DDEMod RLENgth VALue on
222. INIT WAI Starts a new data measurement and waits for the end of the sweep INST SEL IQ ANALYZER Selects the IQ Analyzer channel INIT REFR Refreshes the display for the Analyzer channel Usage Event Manual operation See Refresh on page 163 INITiate lt n gt SEQuencer REFResh ALL This function is only available if the Sequencer is deactivated SySTem SEQuencer SYST SEQ OFF and only in MSRA mode The data in the capture buffer is re evaluated by all active MSRA applications The suffix lt n gt is irrelevant Example SYST SEQ OFF Deactivates the scheduler INIT CONT OFF Switches to single sweep mode INIT WAI Starts a new data measurement and waits for the end of the Sweep INIT SEQ REFR Refreshes the display for all channels Usage Event INITiate lt n gt SEQuencer ABORt This command stops the currently active sequence of measurements The Sequencer itself is not deactivated so you can start a new sequence immediately using INITiate lt n gt SEQuencer IMMediate on page 336 To deactivate the Sequencer use SYSTem SEQuencer on page 337 Performing a Measurement Suffix n irrelevant Usage Event INITiate lt n gt SEQuencer IMMediate This command starts a new sequence of measurements by the Sequencer Its effect is similar to the INITiate lt n gt IMMediate command used for a single measurement Before this command can be e
223. Input INPut ATTenuation PROTection RESet eese nnne nnns 288 dizi mesi ET 288 288 INPut ATTenuation PROTection RESet This command resets the attenuator and reconnects the RF input with the input mixer after an overload condition occured and the protection mechanism intervened The error status bit bit 3 in the STAT QUES POW status register and the INPUT OVLD message in the status bar are cleared For details on the status register see the R amp S FPS User Manual The command works only if the overload condition has been eliminated first Usage Event INPut COUPling lt CouplingType gt This command selects the coupling type of the RF input Parameters lt CouplingType gt AC AC coupling DC DC coupling RST AC Example INP COUP DC Usage SCPI confirmed Manual operation See Input Coupling on page 143 INPut SELect lt Source gt This command selects the signal source for measurements i e it defines which con nector is used to input data to the R amp S FPS If no additional input options are installed only RF input is supported Parameters lt Source gt RF Radio Frequency RF INPUT connector RST RF Manual operation See Radio Frequency State on page 143 Configuring VSA 11 5 2 2 Output Settings The following commands are required to query or provide output at the R amp S FPS con nector
224. LAY OUEWINDOWSM gt REMOVG asea 364 LAYout WINDowsrn REPLAC recette cete tl patte Ce ipe guia e deed eames 364 LAY out WINDOWShD TYPE ttr ri en ee b aee onde d E C E IRR 364 MMEMORY LOAD IQ STATE T m 390 MMEMory STOResn IQ COMMBnt rro ttt tne erre me rn rn n etn Eee 390 MMEMory STORe lt n gt lQ STATe STORGSN 2 OUTPut IRIGger port DIRGCIOR 1 oru rrr eer enter 289 289 OUTPut TRIGgersport OTYPBe oi rrt terrre ener nnn ree A nep enr dnas 290 TRIGger port PULSe IMMediate retten teneret teen tr er rens 290 OUTPut TRIGger port PULSe LENGth STATus QUEStionable ACPLimit C ONDION rtc tt tt tert t ive d 399 S TATUs QUEStonable ACPLEimit ENABI6 2 2 trio co Ree 400 STATus QUEStionable ACPLimit NTRansition ccccccecceceeeeseeeeeeeeeeeeeaeeeseeaeeeeseaeeeseeeeeseeeeeseeneeeeeeneeeees 400 STATus QUEStiOnable ACPLImIEPTRANSIION root coe rtp na 401 STAT s QUEStionable AGPLEimit EVENIE toner b ctr Ren erbe EO o 399 STATus QUEStionable DIQ CONDiition esessseseeeeeeeneneeeneneene
225. MODE ecce tt te ent 318 ine pora dte aate e parat 319 SENS amp IDBEMod EPIater AUTO cadit iiec Eee eee eoe pesi 319 SENSeJDDEMod EPRale VALue 2 uteri 320 SENSe DDEMod EQUalizer 2 320 5 321 gt 20 sete i rete re 321 SENSe DDEMod EQUalizer RESet 322 SENSe DDEMod EQUalizer SAVE cesses nennen nhanh annt nn nnn nns 322 SENS amp 1DDEMod EQUalizer S TT n reote err tr dines 322 SENSe IDDEMOS FS YING AUTO 2 uten cea eter e o cop tecta 322 SENSeJgDDEMGadIESYNcG LEVA pin a teste see a pati re RR Rte iP Ee Pes 322 SENSe DDENMGOGFSYNe RESUlE uua du eet rea 323 SENSe DDEMod FSYNG MODE enencertn ttt tentent tents 323 I SENSe IDDEMOd NIDATa S TATB inicr e dte Ron Romer Ra en ESE aea aieia 323 SENSe DDEMod KDATa NAME center tette ettet tentes 324 SENSe DBEMod NORMalize ADROOD inci cs
226. Modulation Signal Description Signal Continuous Signal Burst Signal Burst Min Length 148 sym 546 462 Max Length 148 sym 546 462 Run In sym 11 077 Run Out B sym 11 077 w Pattern 1 7 Start 3 sym Stop 151 sym Mag CapBuf 1 Cirw Name DGE_TSCC 5 0 0s Descriptio e Burst Lengthi Offset Start 0 sym Stop 1500 sym 09 09 26 Fig 10 7 GSM EDGE burst Pattern is actually located the middle of the burst The correct value for Offset here would be 58 Solution Try one of the following Remove the offset unknown Enter the correct offset within about 4 symbols of tolerance For more information see Offset on page 141 The specified pattern does not coincide with the pattern in your signal In the R amp S FSQ K70 it is possible to search for multiple patterns at the same time For example in a GSM measurement the capture buffer can be checked for all TSCs simultaneously This is not possible in the R amp S FPS K70 Solution Make sure that the correct pattern is specified in the Signal Description dialog mum EIN ERN DAN ECC V E User Manual 1176 8516 02 06 250 R amp S9FPS K70 Optimizing and Troubleshooting the Measurement For more information see chapter 5 4 Signal Description on page 134 Message Result Alignment
227. NSTate on page 281 FSK SENSe DDEMod FSK NSTate on page 279 ASK SENSe DDEMod ASK NSTate on page 277 APSK SENSe DDEMod APSK NSTate 277 FSK Ref Deviation FSK only The FSK Reference Deviation sets the deviation to the reference frequency In case of 2FSK it indicates the distance from the reference frequency to the positive negative deviation frequency and in case of 4FSK the distance to the outer positive negative deviation frequency To set the deviation as a multiple of the symbol rate x SR select Relative mode To set the deviation as an absolute value in Hz select Absolute mode Note that this parameter is available only for FSK modulated signals Remote command CALCulate lt n gt FSK DEViation REFerence VALue page 277 CALCulate lt n gt FSK DEViation REFerence RELative on 276 Modulation Mapping The available mapping types depend on the Modulation Type and Modulation Order For more information on the modulation mapping refer to chapter 4 3 Symbol Map ping on page 67 Remote command SENSe DDEMod MAPPing VALue on page 279 SENSe DDEMod MAPPing CATalog on page 279 Symbol Rate The symbol rate also determines the bandwidth of the data recording and demodu lation You can change the default rate by entering a value in Hz The minimum symbol rate is 25 Hz The maximum symbol rate depends on the defined Sample Rate see chapter 4 2 Sa
228. NSe DDEMod EQUalizer SAVE on page 322 SENSe DDEMod EQUalizer LOAD on page 321 Advanced Demodulation Synchronization You can influence the synchronization process and calculation of error values during demodulation R amp S FPS K70 Configuration The Advanced Demodulation settings are displayed when you do one of the follow ing e Select the Demodulation button from the Overview Select the Demod Meas Filter softkey from the main VSA menu Then switch to the Demodulation Advanced tab A live preview of the constellation with the current settings is displayed in the preview area at the bottom of the dialog box The preview area is not editable directly Demodulation Demodulation Advanced Meas Filter Advanced Normalize EVM to Mean Ref Power Optimization Minimize RMS Error Estimation Points Sym Auto Coarse Synchronization Fine Synchronization Preview Const I Q Meas amp Ref Nomnalize EVI Tacos ieo ved aden e dece e Da edd eine 181 182 Estimation 182 SY Es 183 Fine Synchronization icm dedi ed d dd d d 183 I SER S ecu iiio nt dep epe Ut nee 184 eld M M eee a 184 Normalize EVM to Normalizes the EVM to the specified power value This setting is not available for MSK or FSK modulation
229. NSe JDDEMod SEARCh MBURSESTAIU erat eet rer a ge 374 TRACES DATA ed pret taret aua eati cari CU pd 374 CALCulate lt n gt DELTamarker lt m gt X ABSolute This command queries the absolute x value of the selected delta marker in the speci fied window The command activates the corresponding delta marker if necessary Usage Query only This command queries the relative position of a delta marker on the x axis If necessary the command activates the delta marker first Return values lt Position gt Position of the delta marker in relation to the reference marker Example CALC DELT3 X REL Outputs the frequency of delta marker 3 relative to marker 1 or relative to the reference position Usage Query only Retrieving Results CALCulate lt n gt MARKer lt m gt Y This command queries the position of a marker on the y axis If necessary the command activates the marker first To get a valid result you have to perform a complete measurement with synchroniza tion to the end of the measurement before reading out the result This is only possible for single measurement mode See also INITiate lt n gt CONTinuous on page 333 Return values lt Result gt Result at the marker position Example INIT CONT OFF Switches to single measurement mode CALC MARK2 ON Switches marker 2 INIT WAI Starts a measurement and waits for the end CALC MARK2 Y O
230. Ndard SYNC OFFSet STATe lt PattOffsState gt This command de activates the pattern offset Setting parameters lt PattOffsState gt ON OFF 1 0 RST 0 Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Offset on page 141 SENSe DDEMod STANdard SYNC OFFSet VALue lt PatternOffset gt This command defines a number of symbols which are ignored before the comparison with the pattern starts Setting parameters lt PatternOffset gt numeric value Range 0 to 15000 RST 0 Default unit SYM Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Offset on page 141 Input Output and Frontend Settings The R amp S FPS can analyze signals from different input sources The frequency and amplitude settings represent the frontend of the measurement setup Manual configuration of the input and frontend is described in chapter 5 5 Input Out put and Frontend Settings on page 142 snd 288 LER SUIS M 289 AA aeeai 291 e certe Ett tenter ade Tapa aan 293 Eb cL m 294 and UNO cede ote oec el bap oce dtc e dn 296 Configuring VSA 11 5 2 1 RF
231. OOK Syrmibol mapplilig mE raten ente orbs 85 Optimization ie est ert en 182 Options Bandwidth extension Electronic attenuation Preamplifier B24 OQPSK Constellation diagram 76 Output UO Configuration Configuration softkey IF source remote Sample rate definition ifie Trigger MD ER Overload RF input remote egeta 288 Oversampling e 203 Overview COmiQuratiOn is me br 132 P Parameters DesctiptlOri epe tue 54 55 FSK RI 55 PSK QAM 2 54 Retrieving results remote 377 SCPliparametets nente 54 55 Pattern search 2 reae eren 166 Demodulation process eterne 89 Enabling PES Found Pattern einer 168 correlation threshold 167 Performing 214 Process 92 REMOTE 310 Selected pattetti Juice tere rrr 168 iuri RP 140 Adding to standard erre 170 Assigning to sta dard
232. OPG 306 TRIGger SEQuence S OU ROS noraen e eee ce npn ed copa edo e Ee tk ex PL 306 Configuring VSA TRIGger SEQuence DTIMe lt DropoutTime gt Defines the time the input signal must stay below the trigger level before a trigger is detected again Parameters lt DropoutTime gt Dropout time of the trigger Range 0 sto 10 0s RST 0s Manual operation See Drop Out Time on page 161 TRIGger SEQuence HOLDoff TIME Offset Defines the time offset between the trigger event and the start of the measurement Parameters lt Offset gt The allowed range is 0 s to 30 s RST Os Example TRIG HOLD 500us Manual operation See Trigger Offset on page 160 TRIGger SEQuence IFPower HOLDoff lt Period gt This command defines the holding time before the next trigger event Note that this command can be used for any trigger source not just IF Power despite the legacy keyword Note If you perform gated measurements in combination with the IF Power trigger the R amp S FPS ignores the holding time for frequency sweep FFT sweep zero span and data measurements Parameters lt Period gt Range Os to 10s RST Os Example TRIG SOUR EXT Sets an external trigger source TRIG IFP HOLD 200 ns Sets the holding time to 200 ns Manual operation See Trigger Holdoff on page 161 TRIGger SEQuence IFPower HYSTeresis lt Hysteresis gt
233. OfIKOy det Ete rte 161 Conventions SCPI commands itte rente 265 Copying Measurement channel remote 270 Couple Windows 196 Coupling Input remote x ence ttt ees 288 Customized Measurement performing 212 D Data acquisition Capture t es 156 155 MSRA ceres i pee Roe 156 Usable Bandwidth 156 Data source Capture Dummer 15 BIET Equalizer Error vector Evaluation method 14 Meas amp Ref the Modulation aCcUracy ener nenne enne 17 Modulation isisisi nennen 16 Result types se tay the ririn a Decimal separator Trace export epe ee nente 194 Default values PESOU m Es 128 SCAO iissa 153 Deleting Settings THES eterne 131 131 Delta markers DEMMI e 196 Demodulation Advanced 180 Bandwidth rrt trennt rite re 58 Compensation 176 178 Configuration 2 175 Esti
234. PI standard are indicated as SCPI con firmed All commands used by the R amp S FPS follow the SCPI syntax rules e Asynchronous commands command which does not automatically finish executing before the next com mand starts executing overlapping command is indicated as an Asynchronous command Reset values RST Default parameter values that are used directly after resetting the instrument RST command are indicated as RST values if available Default unit This is the unit used for numeric values if no other unit is provided with the parame ter Manual operation If the result of a remote command can also be achieved in manual operation a link to the description is inserted Introduction 11 1 2 Long and Short Form The keywords have a long and a short form You can use either the long or the short form but no other abbreviations of the keywords The short form is emphasized in upper case letters Note however that this emphasis only serves the purpose to distinguish the short from the long form in the manual For the instrument the case does not matter Example SENSe FREQuency CENTer is the same as SENS FREQ CENT 11 1 3 Numeric Suffixes Some keywords have a numeric suffix if the command can be applied to multiple instances of an object In that case the suffix selects a particular instance e g a mea surement window Numeric suffixes are indicated by angular brackets lt n
235. PPEak STATe sss 350 lt gt 11 353 lt gt 11 5 2 389 lt gt 11 5 enne 350 CALOCulate n LIMit MACCuracy PERRor RCURrent VALue CALOulate n LIMit MACCuracy PERRor RCURrent RESult essent 389 CALOCulate n LIMit MACCuracy PERRor RMEan STATe essen 350 CALOCulate n LIMit MACCuracy PERRor RMEan VALue essent enne nennen 353 CALOCulate n LIMit MACCuracy PERRor RMEan RESUIt eese 389 CALOCulate n LIMit MACCuracy PERRor RPEak STATe sess lt gt 11 22 eren rennen CALCulate lt n gt LIMit MACCuracy PERRor RPEak RESult lt gt 11 5 lt gt 11 lt gt 11 2 389 CALCulate lt n gt LIMit MACCuracy RHO MEAN STATe CALCulate lt n gt LIMit MACCuracy RHO MEAN VALue
236. Pattern Search Auto according to Signal Structure or Advanced Lr I Q Correlation Threshold Auto Meas only if Pattern Symbols Correct Information Selected pattern for Search EDGE TSCO Pattern Found Preview Mag CaptureBuffer 0 sym 1500 Enabling Pattern x vera i E etta ER eee dd 167 VQ Correlation Threshold ect ran ee A dau 167 Meas only if Pattern Symbols Correct nennen 168 Selected Pattern for SEAR isis e c e decade eb e ea etn e e ran 168 MEE CETT PME 168 Enabling Pattern Searches Enables or disables pattern searches If Auto is selected pattern search is enabled only if the signal structure defines a pattern in the signal in the Signal Structure tab of the Modulation amp Signal Description dialog box see Pattern Settings on page 140 Remote command 5 5 DDEMod SEARch SYNC STATe on page 312 on page 311 5 5 DDEMod SEARch JTO Correlation Threshold The correlation threshold decides whether a match is accepted or not during a pat tern search see also chapter 4 4 2 1 0 Pattern Search on page 92 If the parameter is set to 10096 only patterns that match totally with the input signal are found This is only the case for infinite SNR ree User Manual 1176 8516 02 06 167 Burst and Pattern Configuration If th
237. Points per 121 Capture Butter Display eeepc ret e eun pt nh n ERROR UA RARE 122 Known Data Files Dependencies and 123 VSA In MSRA Operating Rotae dit esd 124 Filters and Bandwidths During Signal Processing This section describes the used filters in vector signal analysis with an R amp S FPS as well as the bandwidth after each filter The relevant filters for vector signal analysis are shown in figure 4 1 IQ Demodulation Bandwidth Bandwidth Optional Equalizer Filter Halfband Filter Decimation Filter IF Filter i i Measurement Filter i Digital IF Baseband Baseband Baseband Analog Section Digital Hardware Section DSP Section Fig 4 1 Block diagram of bandwidth relevant filters for vector signal analysis After the IF Filter only for RF input operation bandwidth 40 MHz After the digital hardware section The phase and amplitude distortions of the IF filter have been compensated for Usually the data has a usable bandwidth of about 0 8 sample rate For details refer to chapter 4 1 1 Bandwidth on page 57 Filters and Bandwidths During Signal Processing The data s sample rate and bandwidth are automatically adjusted to the set symbol rate For most modulated signals even the smallest allowed value for t
238. QUEStionable LMARgin lt m gt CONDition lt ChannelName gt STATus QUEStionable MODulation lt n gt CONDition lt ChannelName gt STATus QUEStionable MODulation lt n gt CFRequency CONDition lt ChannelName gt STATus QUEStionable MODulation lt n gt EVM CONDition lt ChannelName gt STATus QUEStionable MODulation lt n gt FSK CONDition lt ChannelName gt STATus QUEStionable MODulation n IQRHo CONDition lt ChannelName gt STATus QUEStionable MODulation lt n gt MAGNitude CONDition lt ChannelName gt STATus QUEStionable MODulation lt n gt PHASe CONDition lt ChannelName gt STATus QUEStionable POWer CONDition lt ChannelName gt STATus QUEStionable SYNC CONDition lt ChannelName gt This command reads out the CONDition section of the status register The command does not delete the contents of the EVENt section Query parameters lt ChannelName gt String containing the name of the channel The parameter is optional If you omit it the command works for the currently active channel Usage Query only STATus QUEStionable ACPLimit EVENt lt ChannelName gt STATus QUEStionable DIQ EVENt lt ChannelName gt STATus QUEStionable FREQuency EVENt lt ChannelName gt STATus QUEStionable LIMit lt m gt EVENt lt ChannelName gt STATus QUEStionable L MARgin m EVENt lt ChannelName gt STATus QUEStionable MODulation lt n gt EVENt lt ChannelName gt STATus QUEStionable MODulation lt n gt CFRequency EVENt lt Ch
239. R amp S FPS K70 Measurements and Result Displays By default all parameters are displayed If you select a specific parameter the Result Summary display is replaced by the individual result display 2 EVM RMS EVM RMS 0 84 1 00 Fig 3 21 Result display for individual value in Result Summary In addition to the current measurement value the statistical results see chap ter 3 2 29 Result Summary on page 47 and the peak limit value see Limit Value on page 200 for the selected parameter are displayed For details on the displayed results see chapter 3 3 Common Parameters in VSA on page 54 Remote command DISPlay WINDow lt n gt ITEM LINE VALue on page 368 3 2 30 Symbol Table Symbol numbers are displayed as a table Each symbol is represented by an entry in the table The symbols can be displayed in binary octal hexadecimal or decimal for mat Selected symbols using markers are highlighted by a blue frame Example 4Symbols Hexadecimal S EP uU 4 208 224 240 256 272 288 304 320 336 352 368 384 400 31 1 fi G9 lt yi i GJ 2 GJ N IJ olu C O GJ IJ C IC WIW lO I 10 jc 1 C fje GJ GJ
240. R amp S9FPS K70 Vector Signal Analysis User Manual Start 0 sym 25000 sym 5 1176 8516 02 06 ROHDE amp SCHWARZ Test amp Measurement User Manual This manual applies to the following R amp S9FPS models with firmware version 1 30 and higher R amp S FPS4 1319 2008K04 R amp S FPS7 1319 2008K07 R amp S FPS13 1319 2008K13 R amp S FPS30 1319 2008K30 R amp S FPS40 1319 2008K40 The following firmware options are described R amp S FPS K70 1321 4127 02 The firmware of the instrument makes use of several valuable open source software packages For information see the Open Source Acknowledgement on the user documentation CD ROM included in delivery Rohde amp Schwarz would like to thank the open source community for their valuable contribution to embedded computing 2015 Rohde amp Schwarz GmbH amp Co KG M hldorfstr 15 81671 M nchen Germany Phone 49 89 41 29 0 Fax 49 89 41 29 12 164 E mail info rohde schwarz com Internet www rohde schwarz com Subject to change Data without tolerance limits is not binding 2459 is a registered trademark of Rohde amp Schwarz GmbH 4 KG Trade names are trademarks of the owners The following abbreviations are used throughout this manual R amp S9FPS is abbreviated as R amp S FPS R amp S FPS K70 Contents Contents MES oo eee ee eee 7 1 1 About this Manual
241. RMalize IQIMbalance lt ComplQImbalance gt This command switches the compensation of the IQ imbalance on or off Setting parameters ComplQImbalance ON OFF 1 0 RST 0 Manual operation See Compensate for PSK MSK ASK QAM on page 178 SENSe DDEMod NORMalize IQOFfset lt ComplQOffset gt This command switches the compensation of the IQ offset on or off Setting parameters lt ComplQOffset gt ON OFF 1 0 RST 1 Manual operation See Compensate for PSK MSK ASK QAM on page 178 SENSe DDEMod NORMalize SRERror lt SymbolClockError gt This command switches the compensation for symbol rate error on or off Setting parameters lt SymbolClockError gt ON OFF 1 0 RST 0 Manual operation See Compensate for PSK MSK ASK QAM on page 178 See Compensate for FSK on page 179 SENSe DDEMod OPTimization lt Criterion gt This command determines the optimization criteria for the demodulation RMSMin Optimization goal is the minimization of RMS of the error vector EVMMin Optimization goal is the minimization of the EVM Configuring VSA Setting parameters Criterion RMSMin EVMMin RMSMin Optimizes calculation such that the RMS of the error vector is minimal EVMMin Optimizes calculation such that EVM is minimal RST RMSMin depends on selected standard Manual operation See Optimization on page 182 SENSe DDEMod SEARch PATTern SYNC AUTO lt UseWfmForSync gt
242. Rate Error For details on these effects see chapter 4 5 2 3 Modulation Errors on page 114 Remote command SENSe DDEMod NORMalize CFDRift on 324 SENSe DDEMod NORMalize FDERror on page 324 SENSe DDEMod NORMalize SRERror on page 325 Equalizer Settings The equalizer can compensate for a distorted transmission of the input signal or improve accuracy in estimating the reference signal For details see chapter 4 4 5 The Equalizer on page 97 State Equalizer Settings Activates or deactivates the equalizer to compensate for a distorted channel Remote command SENSe DDEMod EQUalizer STATe on 322 Mode Equalizer Settings Defines the operating mode of the equalizer Normal Determines the filter values from the difference between the ideal reference signal and the measured signal Normal mode is sufficient for small distortions and performance remains high 5 9 2 Demodulation Settings Tracking The results of the equalizer in the previous sweep are considered to calculate the new filter until adaquate results are obtained This learning effect allows for powerful removement of larger distortions within a minimum of sweeps During the tracking phase calculation of the equalizer requires additional processing time Freeze The filter is no longer changed the current equalizer values are used for subsequent sweeps User A user defined equalizer loaded from a file is
243. Rrent VALue on page 352 Carr Freq Err CALCulate lt n gt LIMit MACCuracy CFERror CURRent VALue on page 351 Check Current Mean Peak Considers the defined limit value in the limit check if checking is activated Remote command CALCulate lt n gt LIMit MACCuracy lt ResultType gt lt LimitType gt STATe on page 350 Display and Window Configuration The captured data can be evaluated using various different methods without having to start a new measurement As opposed to the R amp S FPS Analyzer application or other applications in VSA configuring the result display requires two steps 1 Display Configuration In the first step you select the data source for the evalua tion and the window placement in the SmartGrid The SmartGrid mode is activated automatically when you select the Display Con fig softkey from the main VSA menu or the Display Config button in the Over view Note however that this button is only displayed in the general Overview not for window specific configuration Specifics for must be disabled The default evaluation for the selected data source is displayed in the window Up to 16 result displays can be displayed simultaneously in separate windows The VSA evaluation methods are described in chapter 3 Measurements and Result Displays on page 14 For details on working with the SmartGrid see the R amp S FPS Getting Started man ual 2 Window Configuration In a second step y
244. S 153 Reference position 153 224 Reference value 153 224 fele 150 Scaling eremi i tme 153 Scaling automatically 153 Scaling auto 151 189 Scaling auto all windows 189 B ce E 154 X value Manken idu ect e ette b peer inte 195 Y Y axis Mix max values recettes cu ia es eno vac Ranger Range per division Reference position Reference value Scaling statistics Scaling auto all windows UNITS d 2 Zooming Activating remote acci eret 356 Area Multiple mode remote 956 Area remote 356 Deactivalinig rtr trennt recent 205 Multiple MOde nnne rris 205 Multiple mode remote 956 357 Mete aa 355 Restoring original display 205 Single mode 205 Single mode remote 355
245. SK QAM and MSK specific result summary table can be related to the dis tortion model parameters as follows Table 1 7 Evaluation of results in the PSK QAM and MSK result summary EVM RMS y Xen Peak max EVM n T Modulation RMS error T y 20 log K DIRER TY Peak min MER n T 1 y with MER n T 20 Einer ry Magnitude RMS 1 2 error _ 1 _ ERR n Tp Phase error RMS 1 X _ ERR n T5 Peak max PHASE ERR n T RHO correla tion coeffi cient gt REF n mease _ KKF MEAS REF REF n V wEAsQ AKF REF AKF MEAS 6 2 2 Formulae IQ Offset C 2 2 s 51 50 REF k TY C 10 faB IQ Imbalance j in l el lg 1 8g B 20 10810 faB Gain Imbal g ance G Gin 20 Si G 20 88 Quadrature Error 4 8 180 9 61 deg Amplitud Droop A 20 logio Ay JdB Sym FSK Modulation For FSK modulation the estimation model is described in detail in section chap ter 4 5 2 FSK Modulation on page 110 The parameters of the FSK specific result summary table can be related to the distortion model parameters as follows Table 1 8
246. SM Logical symbol mapping Modulation symbol binary indication MSB LSB 0 1 Phase shift 90 90 4 3 8 Symbol Mapping Fig 4 28 MSK for GSM and NATURAL and DMSK Constellation Diagram including the symbol map ping Similar to PSK differential coding can also be used with MSK In this case too the information is represented by the transition of two consecutive symbols The block dia gram of the coder is shown below Fig 4 29 DMSK differential encoder in the transmitter d input symbol 0 1 of differential encoder d 4 input symbol delayed by the symbol period Ts d output symbol 0 1 of differential encoder The logical symbol mapping is then performed on the XOR coded bitstream 4 Quadrature Amplitude Modulation QAM In the case of QAM the information is represented by the signal amplitude and phase The symbols are arranged in a square constellation in the plane To ensure reliable demodulation symbol numbers should be distributed evenly with respect to the symbol alphabet As a rule of thumb the result length should correspond to at least 8 times the modula tion order For example with 64 QAM a result length of at least 8 64 512 symbols should be used Symbol Mapping QAM Mappings The following QAM mappings are obtained from the mapping of the 1st quadrant which is always rotated by 2 for the subsequent quadrants and supplemented by a GRAY code
247. Se BANDwidth RESolution TYPE NORMal Query SENSe BANDwidth RESolution TYPE would return NORM 11 1 6 4 Character Strings Strings are alphanumeric characters They have to be in straight quotation marks You can use a single quotation mark or a double quotation mark Example INSTRument DELete Spectrum 11 1 6 5 Block Data Block data is a format which is suitable for the transmission of large amounts of data The ASCII character introduces the data block The next number indicates how many of the following digits describe the length of the data block In the example the 4 follow ing digits indicate the length to be 5168 bytes The data bytes follow During the trans mission of these data bytes all end or other control signs are ignored until all bytes are transmitted 0 specifies a data block of indefinite length The use of the indefinite for mat requires a NL END message to terminate the data block This format is useful when the length of the transmission is not known or if speed or other considerations prevent segmentation of the data into blocks of definite length 11 2 Common Suffixes In VSA the following common suffixes are used in remote commands Suffix Value range Description m 1 4 Marker n 1 16 Window lt gt 1 6 11 3 Activating Vector Signal Analysis Vector signal analysis requires a special application on the R amp S FPS A
248. See Marker Type on page 196 CALCulate lt n gt MARKer lt m gt TRACe lt Trace gt This command selects the trace the marker is positioned on Note that the corresponding trace must have a trace mode other than Blank If necessary the command activates the marker first Parameters lt Trace gt 1to6 Trace number the marker is assigned to Analysis Example CALC MARK3 TRAC 2 Assigns marker 3 to trace 2 Manual operation See Assigning the Marker to a Trace on page 196 CALCulate lt n gt MARKer lt m gt X Position This command moves a marker to a particular coordinate on the x axis If necessary the command activates the marker If the marker has been used as a delta marker the command turns it into a normal marker Parameters Position Numeric value that defines the marker position on the x axis Range The range depends on the current x axis range Example CALC MARK2 X 1 7MHz Positions marker 2 to frequency 1 7 MHz Manual operation See X value on page 195 CALCulate lt n gt DELTamarker lt m gt AOFF This command turns all delta markers off lt gt is irrelevant Example CALC DELT AOFF Turns all delta markers off Usage Event CALCulate lt n gt DELTamarker lt m gt STATe State This command turns delta markers on and off If necessary the command activates the delta marker first No suffix at DELTamarker turns on delta marker 1 Parameters State
249. Sult CALCulate lt n gt LIMit MACCuracy RHO PEAK RESult CALCulate lt n gt LIMit MACCuracy lt ResultType gt lt LimitType gt RESUIt This command queries whether the limit for the specified result type and limit type was violated For details on result types and limit types see chapter 3 2 29 Result Summary on page 47 Suffix lt ResultType gt CFERror EVM FDERror FERRor MERRor OOFFset PERRor RHO CFERror Carrier Frequency Error EVM Error Vector Magnitude FDERror Frequency deviation error FSK only FERRor Frequency error FSK only MERRor Magnitude Error OOFFset Offset PERRor Phase Error RHO Rho lt LimitType gt CURRent MEAN PEAK PCURRent PMEan PPEak RCURRent RMEan RPEak For CFERor OOFFset RHO CURRent MEAN PEAK For EVM FDERror FERRor MERRor PERRor PCURRent Peak current value PMEan Peak mean value PPEak Peak peak value RCURRent RMS current value RMEan RMS mean value RPEak RMS peak value User Manual 1176 8516 02 06 389 Importing and Exporting Data and Results Return values lt LimitResult gt NONE PASS FAIL MARGIN NONE No limit check result available yet PASS All values have passed the limit check FAIL At least one value has exceeded the limit MARGIN currently not used RST NONE 11 10 Importing and Exporting Data and Results The I Q data to be evaluated in the VSA application can not only be measured by th
250. Syntax nennen 423 6 a eT e 425 MQ Data File Format iq tar cernerent erneuten nis 439 List of Remote Commands VSA eene 446 oM 456 About this Manual 1 Preface 1 1 About this Manual This R amp S FPS Vector Signal Analysis User Manual provides all the information spe cific to the application All general instrument functions and settings common to all applications and operating modes are described in the main R amp S FPS User Manual The main focus in this manual is on the measurement results and the tasks required to obtain them The following topics are included Welcome to the VSA Application Introduction to and getting familiar with the application Typical applications Example measurement scenarios in which the application is frequently used Measurements and Result Displays Details on supported measurements and their result types Measurement Basics Background information on basic terms and principles in the context of the mea surement Configuration Analysis A concise description of all functions and settings available to configure measure ments and analyze results with their corresponding remote control command Data Import and Export D
251. TLAB pcode To download the tool together with a detailed description see http www rohde schwarz com search term mapwiz Overview of the Demodulation Process 4 4 Overview of the Demodulation Process K70 Kernel Settings IQ Capture Buffer Burst Search optional Q Data Burst Position Demodulation amp Symbol Decisions ptional Ref Signal Measurement Filtering optional Fine Estimates Demodulation Settings Display Configuration Modulation amp Signal Ref Signal Result Display Fig 4 42 Demodulation stages of the vector signal analysis option R amp S FPS K70 Measurement Basics The figure 4 42 provides an overview of the demodulation stages of the vector signal analysis option The function blocks of the signal processing kernel can be found at the left in grey and their appropriate settings at the right in blue A more detailed description of the most important stages is given in the following sec tions Burst Search In this stage the capture buffer is searched for bursts that comply with the signal description The search itself can be switched on or off via the Burst Search dialog see Enabling Burst Searches on page 165 A list of the detected bursts is passed on to the next processing stage Pattern Search The Pattern Search is performed on the capture buffer This means the VSA application
252. TRIGger lt port gt OTYPe lt OutputT ype gt This command selects the type of signal generated at the trigger output Suffix lt port gt Selects the trigger port to which the output is sent 2 TRG AUX Parameters lt OutputType gt DEVice Sends a trigger signal when the R amp S FPS has triggered inter nally TARMed Sends a trigger signal when the trigger is armed and ready for an external trigger event UDEFined Sends a user defined trigger signal For more information see OUTPut TRIGger lt port gt LEVel RST DEVice Manual operation See Output Type on page 145 OUTPut TRIGger lt port gt PULSe IMMediate This command generates a pulse at the trigger output Suffix lt port gt Selects the trigger port to which the output is sent 2 TRG AUX Usage Event Manual operation See Send Trigger on page 145 OUTPut TRIGger lt port gt PULSe LENGth lt Length gt This command defines the length of the pulse generated at the trigger output Configuring VSA Suffix port Selects the trigger port to which the output is sent 2 AUX Parameters Length Pulse length in seconds Manual operation See Pulse Length on page 145 11 5 2 3 Frequency SENSe FREQuency CENTER icit rope e dE e pae e teed pee tet Me Pana 291 SENSe FREQuesncy CEN Ter STEP iieri IA XR YR FE ER XR ATE 291
253. The search includes only measurement values to the right of the current marker posi tion Usage Event CALCulate lt n gt MARKer lt m gt MAXimum PEAK This command moves a marker to the highest level If the marker is not yet active the command first activates the marker Usage Event Manual operation See Peak Search on page 198 Analysis CALCulate lt n gt MARKer lt m gt MINimum LEFT This command moves a marker to the next minimum value The search includes only measurement values to the right of the current marker posi tion Usage Event CALCulate lt n gt MARKer lt m gt MINimum NEXT This command moves a marker to the next minimum value Usage Event Manual operation See Search Next Minimum on page 198 CALCulate lt n gt MARKer lt m gt MINimum RIGHt This command moves a marker to the next minimum value The search includes only measurement values to the right of the current marker posi tion Usage Event CALCulate lt n gt MARKer lt m gt MINimum PEAK This command moves a marker to the minimum level If the marker is not yet active the command first activates the marker Usage Event Manual operation See Search Minimum on page 198 CALCulate lt n gt MARKer lt m gt SEARch lt MarkReallmag gt This command specifies whether the marker search works on the real or the imag trace for all markers Setting parameters lt MarkReallmag gt REAL IMAG RST REAL Manual operation See
254. This command has no effect on the transmit filter Setting parameters lt MeasFilterState gt ON OFF 1 0 ON SENSe DDEMod MFILter AUTO is activated OFF The input signal is not filtered SENSe DDEMod MFILter AUTO is deactivated RST 1 SENSe DDEMod FORMat lt Group gt This command selects the digital demodulation mode Setting parameters lt Group gt Example MSK PSK QAM QPSK FSK ASK APSK UQAM QPSK Quad Phase Shift Key PSK Phase Shift Key MSK Minimum Shift Key QAM Quadrature Amplitude Modulation FSK Frequency Shift Key ASK Amplitude Shift Keying APSK Amplitude Phase Shift Keying UQAM User defined modulation loaded from file see SENSe DDEMod USER NAME on page 284 RST PSK SENS DDEM FORM QAM Configuring VSA Example See chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Modulation Type on page 135 See Load User Modulation on page 136 SENSe DDEMod FSK NSTate lt FSKNstate gt This command defines the demodulation of the FSK modulation scheme Setting parameters lt FSKNstate gt 21418 2 2FSK 4 4FSK 8 8FSK RST 2 Manual operation See Modulation Order on page
255. This command selects the trace mode In case of max hold min hold or average trace mode you can set the number of single measurements with SENSe SWEep COUNt VALue Note that synchronization to the end of the measurement is possible only in single sweep mode Depending on the result display not all trace modes may be available Parameters Mode WRITe Overwrite mode the trace is overwritten by each sweep This is the default setting AVERage The average is formed over several sweeps The Sweep Aver age Count determines the number of averaging procedures MAXHold The maximum value is determined over several sweeps and dis played The R amp S FPS saves the sweep result in the trace mem ory only if the new value is greater than the previous one MINHold The minimum value is determined from several measurements and displayed The R amp S FPS saves the sweep result in the trace memory only if the new value is lower than the previous one VIEW The current contents of the trace memory are frozen and dis played BLANk Hides the selected trace RST Trace 1 WRITe Trace 2 6 BLANk 11 7 2 11 7 2 1 Analysis Example INIT CONT OFF Switching to single sweep mode SWE COUN 16 Sets the number of measurements to 16 DISP TRAC3 MODE WRIT Selects clear write mode for trace 3 INIT WAI Starts the measurement and waits for the end of the measure ment Manual operation See Trace Mode on page 191
256. V f MEAS t e e 4 5 2 2 Estimation The estimation of the distortion parameters listed previously is performed separately for the magnitude and phase frequency distortions as illustrated in figure 4 60 It is noted that the estimation of the timing offset is performed only on the frequency of the signal as the reference magnitude is assumed to be constant over the estimation range For details on the estimation range see Estimation ranges on page 101 Signal Model Estimation and Modulation Errors Compute Reference Waveform Estimate Timing Ref deviation Compute d Meas Frequency i Filter Carrier offset Carrier drift Signal Estimate Gain Amp droop Compute Magnitude Fig 4 60 FSK Estimation Strategy In figure 4 60 MEAS n denotes the sampled complex baseband measured signal waveform The magnitude samples are denoted Aye s n while the instantaneous fre quency samples of the measured and reference signals are denoted by fyyeqs n and fage n respectively The dashed outline of the Meas Filter block indicates that this operation is optionally de activated based on the corresponding user settings see Type on page 186 For the estimation of the magnitude parameters the following least squares criterion is minimized 2 Ka Auzas n Ke n with respect to the model parameters and where Tg denotes the sampling period used for
257. YPE2 NORMal DIFFerential TYPE1 NORMal Demodulation order MSK is used TYPE2 DIFFerential Demodulation order DMSK is used RST TYPE1 Manual operation See Modulation Order on page 136 SENSe DDEMod PSK FORMat PSKformat Together with DDEMod PSK NST this command defines the demodulation order for PSK see also SENSe DDEMod PSK NSTate page 281 Depending on the demodulation format and state the following orders are available NSTATe lt Name gt Order 2 any BPSK 8 NORMal 8PSK 8 DIFFerential D8PSK 8 N3Pi8 3pi 8 8PSK EDGE 8 PI8D8PSK Pi 8 D8PSK Setting parameters lt PSKformat gt NORMal DIFFerential N3Pi8 PIBD8PSK RST NORMal Manual operation See Modulation Order on page 136 Configuring VSA SENSe DDEMod PSK NSTate lt PSKNstate gt Together with DDEMod PSK FORMat this command defines the demodulation order for PSK see also SENSe DDEMod PSK FORMat on page 280 Setting parameters lt PSKNstate gt 218 RST 2 Manual operation See Modulation Order on page 136 SENSe DDEMod QAM FORMat lt QAMformat gt This command defines the specific demodulation order for QAM Setting parameters lt QAMformat gt NORMal DIFFerential NPI4 MNPI4 NORMal Demodulation order QAM is used DIFFerential Demodulation order DQAM is used 4 Demodulation order 11 4 16QAM is used MNPI4 Demodulation order 11 4 32QAM
258. a or the filter bandwidth BT The roll off factor and filter bandwidth for transmit filter is available for RC RRC Gauss and GMSK filter Remote command SENSe DDEMod TFILter ALPHa on page 283 5 4 2 Signal Structure The Signal Structure settings describe the expected input signal and determine which settings are available for configuration You can define a pattern to which the instru ment can be synchronized thus adapting the result range A visualization of the currently defined signal structure is displayed at the bottom of the dialog box The Signal Structure settings are displayed when you do one of the following Select the Signal Description button in the Overview e Select the Signal Description softkey the main VSA menu R amp S9 FPS K70 Configuration Then switch to the Signal Structure tab 148 Sig Modulation Signal Structure Known Data Signal Type Continuous Signal Burst Signal Burst 148 sym 546 462 A e U M 148 sym 546 462 ps Run In sym 11 077 ps Run Out 3 sym 11 077 ps Pattern Name EDGE_TSCO g Pattern Config Offset 58 sym 214 154 ps Description Signal e M 139 o E E A pti et 140 L Min Length Max Length cccc
259. a file A maximum of 60 characters can be displayed Remote command SENSe DDEMod STANdard COMMent on page 274 Load Standard Digital Standards Loads the selected measurement settings file Note When you load a standard the usage of a known data file if available is auto matically deactivated Remote command SENSe DDEMod PRESet STANdard page 274 Save Standard Digital Standards Saves the current measurement settings for a specific standard as a file with the defined name Remote command SENSe DDEMod STANdard SAVE on page 275 Delete Standard Digital Standards Deletes the selected standard Standards predefined by Rohde amp Schwarz can also be deleted A confirmation query is displayed to avoid unintentional deletion of the stand ard Note Restoring predefined standard files The standards predefined by Rohde amp Schwarz available at the time of delivery can be restored using the Restore Stand ards function see Restore Standard Files on page 129 Remote command SENSe DDEMod STANdard DELete on page 274 Restore Standard Files Digital Standards Restores the standards predefined by Rohde amp Schwarz available at the time of deliv ery Note that this function will overwrite customized standards that have the same name as predefined standards Remote command SENSe DDEMod FACTory VALue on 273 Configuration Overview 5 3 Configurati
260. ace data Traces External trigger Level remote eed Eye diagram Frequency result type 2 27 Imag Q result type m Real 1 result type 2 024424111 29 F Factory settings IReSIOLIFIQ icis recreo UO ete Lex oe 129 File name SeltligSt e etis eva meteo Ede Oen Ere EE ed 130 Files Format VQ data cn tc deett 439 I Q data binary XML ies parameter XML ertet 440 Filter bandwidth BT Measurement 186 Transmit filter 138 Filters De ModulatiOl 58 Customized m Customized creating 61 Customized selecting 0 4442222221 213 Formulae csset uar squad ERR 431 Measurement 58 59 420 Measurement formulae 433 Predefined Receive Reference 2 Signal tre teneris 56 Standard specific 432 58 419 Transmit formulae 432 Typcial Combinations nne en 421 MB PE 61 Fine Synchronizatlon caza 183 Folders Digital staridatds te ne 130 Formulae Analytically calculated
261. age 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 6 Equalizer on page 377 Impulse Response Real Imag The Real Imag diagram of the impulse response is a stem diagram It displays the filter characteristics in the time domain for both the and the Q branches individually Using this information the equalizer is uniquely characterized and can be recreated by other applications res User Manual 1176 8516 02 06 38 R amp S9FPS K70 Measurements and Result Displays 3 2 21 1 Real ImpRespReallmag Equalizer 1 Imag ImpRespReallmag Equalizer Available for source types Equalizer Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow on page 359 CALC FEED XTIM DDEM IMP to define the impulse response result type see CALCulate lt n gt FEED on page 365 CALC FORM RIM to define the real image result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 6 Equalizer on page 377 Magnitude Absolute Magnitude of the source signal in an individual capture buffer range max 256 000 samples If more than 256 000 samples are captured overlapping result ranges with a size of 256 000 samples each are created Only one range at a ti
262. ains all operating modes and applications currently available on your R amp S FPS 2 Select the VSA item HA VSA The R amp S FPS opens a new measurement channel for the VSA application The measurement is started immediately with the default settings It can be configured in the VSA Overview dialog box which is displayed when you select the Overview softkey from any menu see chapter 5 3 Configuration Overview on page 132 Multiple Measurement Channels and Sequencer Function When you activate an application a new measurement channel is created which deter mines the measurement settings for that application The same application can be acti vated with different measurement settings by creating several channels for the same application The number of channels that can be configured at the same time depends on the avail able memory on the instrument Only one measurement can be performed at any time namely the one in the currently active channel However in order to perform the configured measurements consecu tively a Sequencer function is provided If activated the measurements configured in the currently active channels are per formed one after the other in the order of the tabs The currently active measurement is indicated by 48 symbol in the tab label The result displays of the individual channels are updated in the tabs as well as the MultiView as the measurements are per formed Sequential operatio
263. al Sweeps RPE Maximum value of RMS EVM over several sweeps SDEV Standard deviation of EVM values over several sweeps TPE Maximum EVM over all display points over several sweeps Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic FDERror type This command queries the results of the FSK deviation error of FSK modulated sig nals Retrieving Results Query parameters type none Deviation error for current sweep Average FSK deviation error RPE Peak FSK deviation error SDEV Standard deviation of FSK deviation error PCTL 95 percentile value of FSK deviation error Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic FSK CFDRift type This command queries the results of the carrier frequency drift for FSK modulated sig nals Query parameters type none Carrier frequency drift for current sweep AVG Average FSK carrier frequency drift over several sweeps RPE Peak FSK carrier frequency drift over several sweeps SDEV Standard deviation of FSK carrier frequency drift PCTL 95 percentile value of FSK carrier frequency drift Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic FSK DERRo
264. ale Config gt Y Axis Max Value 5 Enter the upper limit in the current unit The y axis is adapted to display the specified range Probabilities of occurrence located outside the display area are applied to the bars at the left or right borders of the display 8 3 2 How to Check Limits for Modulation Accuracy The results of a modulation accuracy measurement can be checked for violation of defined limits automatically If limit check is activated and the measured values exceed the limits those values are indicated in red in the result summary table If limit check is activated and no values exceed the limits the checked values are indicated in green O ee User Manual 1176 8516 02 06 225 R amp S FPS K70 How to Perform Vector Signal Analysis B Result Summary Current Mean StdDev _95 ile 100 00 Gain Imbalance 0 00 Quadrature Error 0 00 Amplitude Droop For details on the limit check functions and settings see chapter 6 4 Modulation Accu racy Limit Lines on page 199 To define a limit check 1 Configure a measurement with Modulation Accuracy as the Source see chap ter 6 5 Display and Window Configuration on page 201 2 Press the LINES key 3 Press the ModAcc Limits Config softkey in the Limits menu 4 n the Current tab define limits that the current value should not exceed for any or all of the result types Note the limits for the current value are automatically a
265. all mag Meas amp Ref Reallmag Meas amp Ref has the unit none In this case none means the measured signal has been scaled such that it matches the ideal corresponding ref erence signal as well as possible The reference signal in turn is scaled such that max abs at symbol instants 1 0 Question How can I get the demodulated symbols of all my GSM bursts in the capture buffer in remote control Answer Use the following remote commands SENSel DDEMod PRESet GSM NB Load the GSM standard SENSel1 DDEMod RLENgth 10000 SYM Enlarge the capture buffer length such that all the bursts you want to demodulate can be seen within the capture buffer INITiatel CONTinuous OFF Go to single sweep mode User Manual 1176 8516 02 06 261 Obtaining Technical Support SENSe1 SWEep COUNCt 0 Set the Statistic Count to Auto mode INITiatel IMMediate Do single sweep SENSe1 SWEep COUNt CURRent Query the number of demodulated bursts within the capture buffer For n 1 NumberOfBursts SENSe1 DDEMod SEARCh MBURSt CALC n TRACe4 TRACel Query the result symbols in window D End Step through all bursts and query the demodulated symbols Question Why do the EVM results for my FSK modulated signal look wrong Answer For an FSK modulated signal the signal processing differs to an PSK QAM MSK modulated signal The estimation model does not minimize the EVM but the error of the instantaneo
266. als on page 235 Programming Examples Note that although this example uses the settings from a predefined digital standard the configuration is changed to demonstrate the possibilities of the VSA application A measurement that is performed strictly according to the standard requires much less programming efforts The rising and falling edges of a GSM burst are analyzed using the following result range settings Result Range Evaluation Range Length CERT IESU 200 sym 738 462 us Reference Pattern Waveform Alignment 4 gt Right Offset Symbol Number at Burst Start 10 sym Visualization RST Reset the instrument FREQ CENT 1GHz Set the center frequency DISP TRAC Y RLEV 4dBm Set the reference level INST CRE NEW DDEM VSA Create new measurement channel for vector signal analysis named VSA DDEM PRES EDGE NB Loads the GSM EDGE 8PSK standard file and the settings defined there Programming Examples DDEM RLEN 10000 sym Defining the result range DDEMod TIME 200 Defines the result length as 200 symbols CALC TRAC ADJ BURS Defines the burst as the reference for the result range CALC TRAC ADJ ALIG LEFT Aligns the result range to the left edge of the burst CALC TRAC ADJ ALIG OFFS 10 Defines an offset of 10 symbols from the burst start DISP TRAC X VOFF 10 Defines the s
267. alues to a file and load them again later This is useful if signals from the same input source are measured frequently In this case you only have to perform a calculation once and can use the same equalizer filter again and again Filter length The length of the equalizer can be defined in symbols The longer the equalizer the higher the resolution in the frequency domain is and the more distortion can be com pensated The shorter the filter length the less calculation time is required during the equalizer s tracking or averaging phase Estimation points per symbol You can define how many sample points are used for the equalizer calculation at each symbol Estimation points per symbol see chapter 4 7 Display Points vs Estimation Points per Symbol on page 121 Typically this is one point per symbol symbol rate or a factor of 2 Channel EVM The equalizer not only compensates for distortions in the measurement signal but also improves the accuracy of the estimated ideal reference signal Thus it is usually rec ommendable to enable the equalizer once you have analyzed the original input signal on the R amp S FPS By default the error results are calculated using the compensated values if the equalizer is enabled However you can disable the compensation for channel results in order to analyze the actual error values obtained from the distorted channel User Manual 1176 8516 02 06 99 Signal Model Estimation and Modu
268. am according to the mapping rule BPSK NATURAL Fig 4 7 Constellation diagram for BPSK including the symbol mapping QPSK Fig 4 8 Constellation diagram for QPSK including the symbol mapping for CDMA2000 FWD and DVB 52 Symbol Mapping Fig 4 11 Constellation diagram for QPSK including the symbol mapping for WCDMA Symbol Mapping 8PSK 2 N 3 Fig 4 14 Constellation diagram 8PSK including the symbol mapping for DVB S2 Symbol Mapping 4 3 2 Rotating PSK A rotating PSK modulation is basically a PSK modulation in which additional phase shifts occur These phase shifts depend on the symbol number e g for a 4 the third symbol has an additional phase offset of 3 1 rr 4 This offset has the same effect as a rotation of the basic system of coordinates by the offset angle after each symbol The method is highly important in practical applications because it prevents signal tran sitions through the zeros in the plane This reduces the dynamic range of the modulated signal and the linearity requirements for the amplifier In practice the method is used for 311 8 8PSK for example and in conjunction with phase differential coding for rr 4 DQPSK Symbol mapping The logical constellation diagram for 3 8 8 comprises 8 points that correspond to the modulation level see figure 4 15 A counter clockwise offset rotation of 3171 8 is inserted after each symbo
269. ample DISP FORM SPL DISPlay WINDow lt n gt SIZE Size This command maximizes the size of the selected result display window temporarily To change the size of several windows on the screen permanently use the LAY SPL command see LAYout SPLitter on page 361 Parameters Size LARGe Maximizes the selected window to full screen Other windows are still active in the background SMALI Reduces the size of the selected window to its original size If more than one measurement window was displayed originally these are visible again RST SMALI Example DISP WIND2 LARG Configuring the Result Display 11 8 2 Working with Windows in the Display The following commands are required to change the evaluation type and rearrange the screen layout for a measurement channel as you do using the SmartGrid in manual operation Since the available evaluation types depend on the selected application some parameters for the following commands also depend on the selected measure ment channel Note that the suffix n always refers to the window in the currently selected measure ment channel see INSTrument SELect on page 272 LA Y OURA DDI WINDOW e er o en E e e rc ex 359 LAYout GATalog WINDOW 5 uade vd koe Rev uL aso 360 LAYoutIDENUVIWINDONWJS 32 3 nant lances esae eaux 361
270. an Analysis Interval and Line MSRA mode 354 e Zooming into the Displays ctc et d tenet Ec i ne du ge 355 Configuring Traces The trace settings determine how the measured data is analyzed and displayed on the Screen Depending on the result display between 1 and 6 traces may be displayed Manual configuration of traces is described in chapter 6 1 Trace Settings on page 190 Commands for storing trace data are described in chapter 11 9 1 Retrieving Trace Data and Marker Values on page 371 Useful commands for trace configuration described elsewhere DISPlay WINDow lt n gt TRACe lt t gt Y SCALe on page 299 Remote commands exclusive to trace configuration CAL Gulatesn TRAGest VALus 2i ettet ool Rn en x ERE ERR 338 lt gt lt gt nenne emen memes 339 DISPlay WINDow lt n gt TRACE lt tHE STATE denda cn autos cub eei 340 CALCulate lt n gt TRACe lt t gt VALue lt TrRefType gt This commands selects the signal to be used as the data source for a trace Suffix lt t gt 1 6 Analysis Setting parameters TrRefType MEAS Measurement signal REF Reference signal RST Depends on the current measurement Usage SCPI confirmed Manual operation See Evaluation on page 192 DISPlay WINDow lt n gt TRACe lt t gt MODE Mode
271. ange 173 Demodulation SettinGS 2 ccc cccccccsssececscccccceescctsaeecescteccecesstucceceestuneaecessveeceesesdestceeses 175 Measurement Filter 95 185 Evaluation Range Configuration eese 187 Adjusting Settings Automatically esee 188 DL LI Me 190 Trace Settings 190 Trace Export 8 193 194 Modulation Accuracy Limit 1 11 nnnm 199 Display and Window Configuration eee nnn 201 ZOOM 204 Data Import 206 Imiport Export FUNCIONS 206 How to Export and Import I Q 1111 208 How to Perform Vector Signal 210 How to Perform VSA According to Digital Standards 210 How to Perform Customized VSA Measurements
272. anges button and define which of the captured data is to be demodulated see chapter 8 2 4 How to Define the Result Range on page 220 9 Select the Demodulation button to configure and optimize the synchronization process 10 Select the Meas filter button to select a different or user defined measurement fil ter to improve the accuracy of the error vector see chapter 8 2 1 How to Select User Defined Filters on page 213 11 Select the Evaluation Range button to define which part of the demodulated data is to be evaluated and displayed 12 Press the RUN SINGLE key to stop the continuous sweep and start a new sweep with the new configuration The measured data is stored in the capture buffer and can be analyzed see chap ter 8 3 How to Analyze the Measured Data on page 221 8 2 1 How to Select User Defined Filters The most frequently required measurement and TX filters required for vector signal analysis according to digital standards are provided by the R amp S FPS VSA application However you can also load user defined filters To load a user measurement filter 1 In the Overview select the Meas Filter button 2 In the Meas Filter tab of the Demodulation amp Measurement Filter dialog box select Type User 3 Select Load User Filter 4 Load your vaf file from the USB stick To load a user transmit TX filter 1 In the Overview select the Signal Description button 2 In t
273. anggs coiere incen rennen nnnm a aeo inna as AAEREN aa ka ne Esa Ra aano auus 116 4 7 Display Points vs Estimation Points per 121 4 8 Capture Buffer 05 inn tenera nnne nur 122 4 9 Known Data Files Dependencies and 123 4 10 VSA MSRA Operating nennen nennen nennen 124 NEU DI eer R 127 5 1 Default Settings for Vector Signal Analysis eene 128 5 2 Configuration According to Digital 222 20 129 5 3 Configuration Overview nuper ornare eon aea 132 5 4 Signal Descrip UON ceira repere 134 5 5 Input Output and Frontend 5 4404 4 1122 142 950 Signal Captute 4 tenete aime aides ietes 154 5 7 Burst and Pattern 164 User Manual 1176 8516 02 06 3 R amp S FPS K70 Contents 5 8 5 9 5 10 5 11 5 12 6 1 6 2 6 3 6 4 6 5 6 6 7 1 7 2 8 1 8 2 8 3 9 1 9 2 9 3 10 10 1 10 2 10 3 10 4 11 11 1 11 2 Result R
274. annel Frequency Response Group Delay on page 22 The default result type is Frequency Response Magnitude Remote command LAY ADD 1 BEL EQU see LAYout ADD WINDow on page 359 E User Manual 1176 8516 02 06 17 Result Types in VSA 3 2 Result Types in VSA The available result types for a window depend on the selected evaluation data source The SCPI parameters in the following table refer to the CALC FORM command see CALCulate lt n gt FORMat on page 366 Table 3 1 Available result types depending on data source Evaluation Data Result Type SCPI Parameter Source Capture Buffer Magnitude Absolute MAGNitude Real Imag RIMag Frequency Absolute FREQuency Vector I Q COMP Magnitude Overview Absolute MOVerview Meas amp Ref Signal Magnitude Absolute MAGNitude Magnitude Relative MAGNitude Phase Wrap PHASe Phase Unwrap UPHase Frequency Absolute FREQuency Frequency Relative FREQuency Real Imag 1 RIMag Eye Diagram Real 1 IEYE Eye Diagram Imag Q QEYE Eye Diagram Frequency FEYE Constellation CONS Constellation Rotated RCON Vector COMP Constellation Frequency CONF Vector Frequency COVF Symbols Binary Octal 5 Decimal Hexadecimal Error Vector EVM MAGNItude Real Imag 1 RIMag Result Types in Evaluation Data Result Ty
275. annelName gt STATus QUEStionable MODulation lt n gt EVM EVENt lt ChannelName gt STATus QUEStionable MODulation lt n gt FSK EVENt lt ChannelName gt STATus QUEStionable MODulation lt n gt IQRHo EVENt lt ChannelName gt STATus QUEStionable MODulation lt n gt MAGNitude EVENt lt ChannelName gt STATus QUEStionable MODulation lt n gt PHASe EVENt lt ChannelName gt User Manual 1176 8516 02 06 399 R amp S FPS K70 Remote Commands for VSA STATus QUEStionable POWer EVENt lt ChannelName gt STATus QUEStionable SYNC EVENt lt ChannelName gt This command reads out the EVENt section of the status register The command also deletes the contents of the EVENt section Query parameters lt ChannelName gt String containing the name of the channel The parameter is optional If you omit it the command works for the currently active channel Usage Query only STATus QUEStionable ACPLimit ENABle lt BitDefinition gt ChannelName STATus QUEStionable DIQ ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable FREQuency ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable LIMit lt m gt ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable LMARgin lt m gt ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt CFRequency ENABle lt BitDefinition g
276. anual 1176 8516 02 06 35 R amp S9FPS K70 Measurements and Result Displays 3 2 17 1 FreqRespMag Equalizer Start 100 MHz Stop 100 MHz Available for source types e Equalizer Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow page 359 CALC FEED XFR DDEM RAT to define the frequency response result type see CALCulate lt n gt FEED on page 365 CALC FORM MAGN to define the magnitude result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 6 Equalizer on page 377 Frequency Response Phase The frequency response phase of the equalizer is derived from the Frequency Response Magnitude Available for source types Equalizer Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow page 359 CALC FEED XFR DDEM RAT User Manual 1176 8516 02 06 36 R amp S9FPS K70 Measurements and Result Displays 3 2 18 to define the frequency response result type see CALCulate lt n gt FEED on page 365 CALC FORM UPH to define the unwrapped phase result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt
277. apter 8 2 2 3 How to Manage Pat terns on page 217 The list can be filtered using the following functions Prefix Displaying available patterns Shows only patterns that contain the specified prefix Show Compatible Show Displaying available patterns Shows only patterns that are compatible to the selected modulation mode or all pat terns regardless of the selected standard Edit Opens the Edit Pattern dialog box to edit the pattern definition See chapter 5 7 4 Pattern Definition on page 171 For details on defining a pattern see example Defining a pattern on page 216 Remote command SENSe DDEMod SEARch SYNC NAME on page 314 SENSe DDEMod SEARch SYNC COMMent on page 312 SENSe DDEMod SEARch SYNC DATA on page 313 SENSe DDEMod SEARch SYNC TEXT on page 315 Save As Saves a copy of an existing pattern under a new name Remote command SENSe DDEMod SEARch SYNC COPY on page 313 New Opens the Pattern dialog box to create a new pattern definition See chapter 5 7 4 Pattern Definition on page 171 Burst and Pattern Configuration For details on defining a pattern see example Defining a pattern on page 216 Remote command SENSe DDEMod SEARch SYNC NAME on page 314 SENSe DDEMod SEARch SYNC COMMent on page 312 SENSe DDEMod SEARch SYNC DATA on page 313 SENSe DDEMod SEARch SYNC TEXT on page 315 Delete Deletes the selected patterns
278. ata This command defines the length of the measurement if SENSe ADJust CONFigure DURation MODE is set to MANual Parameters Duration Numeric value in seconds Range 0 001 to 16000 0 RST 0 001 Default unit s Example ADJ CONF DUR MODE MAN Selects manual definition of the measurement length ADJ CONF LEV DUR 5ms Length of the measurement is 5 ms Manual operation See Changing the Automatic Measurement Time Meastime Manual on page 189 SENSe ADJust CONFigure DURation MODE Mode In order to determine the ideal reference level the R amp S FPS performs a measurement on the current input data This command selects the way the R amp S FPS determines the length of the measurement Configuring VSA Parameters Mode AUTO The R amp S FPS determines the measurement length automati cally according to the current input data MANual The R amp S FPS uses the measurement length defined by SENSe ADJust CONFigure DURation on page 330 RST AUTO Manual operation See Resetting the Automatic Measurement Time Meastime Auto on page 189 See Changing the Automatic Measurement Time Meastime Manual on page 189 SENSe ADJust CONFigure HYSTeresis LOWer Threshold When the reference level is adjusted automatically using the SENSe ADJust LEVel on page 332 command the internal attenuators and the preamplifier are also adjusted In order to avoid frequent adaptation due to small changes
279. ata has been stored in the capture buffer the results can be analyzed in numerous ways The following tasks are meant to make you familiar with the most How to Analyze the Measured Data common application features For a description of all analysis functions and set tings see chapter 6 Analysis on page 190 1 Press the MEAS CONFIG key to display the VSA menu 2 Select the Display Config button in the Overview or the Display Config softkey and select the data sources for evaluation that are of interest to you see chap ter 6 5 Display and Window Configuration on page 201 Arrange them on the display to suit your preferences For each data source a window with the default result type for that data source is displayed 3 Exit the SmartGrid mode 4 Select the Window Config softkey to change the result types and other display settings for the selected window To change the settings in other windows select a different window from the Specifics for list in the Window Config dialog box 5 Select the Overview softkey to display the Overview Enable the Specifics for option to access the analysis functions for the selected window 6 Select the Analysis button in the Overview to configure special analysis settings for the individual result displays for example e Configure markers and delta markers to determine deviations and offsets within the results e g when comparing errors or peaks e Co
280. ate see SENSe DDEMod PRATe on page 301 Setting parameters lt LinkMode gt ON OFF 1 0 RST 1 Manual operation See Estimation Points Sym on page 182 SENSe DDEMod EPRate VALue lt EstOverSmplg gt Defines how many sample points are used at each symbol to calculate modulation accuracy results For more information see Estimation points per symbol on page 121 You can also let the VSA application decide how many estimation points to use see SENSe DDEMod EPRate AUTO on page 319 Setting parameters lt EstOverSmplg gt 1 the estimation algorithm takes only the symbol time instants into account 2 two points per symbol instant are used required for Offset QPSk 4 8 16 32 the number of samples per symbol defined in the signal capture settings is used see SENSe DDEMod PRATe on page 301 i e all sample time instants are weighted equally RST 1 Manual operation See Estimation Points Sym on page 182 SENSe DDEMod EQuUalizer LENGth lt FilterLength gt This command defines the length of the equalizer in terms of symbols Setting parameters lt FilterLength gt numeric value Range 1 to 256 RST 10 Default unit SYM Example DDEM EQU LENG 101 Sets the equalizer length to 101 symbols Configuring VSA Manual operation See Filter Length on page 180 SENSe DDEMod EQUalizer LOAD Name This command selects a user defined equalizer The equalizer
281. atistics Diagrams Statistic diagrams show the distribution i e probabilities of occurrence of the values as a set of bars You can define the number of bars to be displayed i e the granularity of classifications Additionally you can specify whether absolute or percentage values are displayed For statistics measurements both the x axis and the y axis can be scaled to optimize the display The range of the displayed x axis for statistics diagrams can be defined in the following Ways manually by defining reference values and positions e automatically according to the current results The range of the displayed y axis can be defined in the following ways manually by defining the minimum and maximum values to be displayed automatically according to the current results After changing the scaling you can restore the default settings To define the number of bars 1 Focus the result window 2 Select AMPT XScale Config X Axis Quantize 3 Enter the number of bars to be displayed The diagram is adapted to display the specified number of bars To define the x axis scaling manually using a reference point and divisions With this method you define a reference value on the x axis to be displayed at the Ref Position of the y axis The reference value is determined internally according to the displayed data and cannot be changed The beginning of the diagram is at the position 096 the end is at 10096 Additional
282. average of the number of results defined by the Statistic Count Peak value e Standard deviation 95 percentile Unlike the mean value the 95 ile is a result of all measurement results since the last start of a single or continous sweep or of all measurements since the last change of a measurement parameter Retrieving Results For details on the individual parameters see chapter 3 3 Common Parameters in VSA on page 54 and chapter A 6 Formulae on page 425 GAL GulatesmsBERd le inre EID IRI 378 lt gt lt gt 378 lt gt lt gt 379 CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic 2 379 lt gt lt gt 380 CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic 2 380 gt lt gt 5 5 2 381 CALCulate n MARKer m FUNCtion DDEMod STATistic c FSK DERROr 381 CALCulate n MARKer m
283. ay WINDow5 TRACe2 MODE AVER Add second trace in average mode DISPlay WINDow5 TRACe3 MODE MAXH Add a third trace in max hold mode SWE COUN 10 Calculate an average over 10 sweeps Programming Examples INIT CONT OFF Select single sweep mode INIT WAI Initiate a new measurement and wait until the 10 sweeps have finished DISP WIND1 SIZE LARG Display the I Q Constellation result display window 1 in full screen HCOP DEST MMEM Define the destination of the screenshot as a file HCOP DEV LANG BMP Select bmp as the file format MMEM NAME C R_S INST USER IQConstellation bmp Select the file name for the printout HCOP ITEM ALL Print all screen elements HCOP Store the printout in a file called IQConstellation bmp DISP WIND5 SIZE SMAL Restore the I Q Constellation result display to one subwindow FORM DEXP HEAD ON Include a header in the trace export file FORM DEXP MODE TRAC Export the trace data not raw I Q data MMEM STOR4 TRAC 1 AverageEVM Save the detected symbol values x values are not exported with trace data Results MMEM STOR5 TRAC 1 AverageEVM Save the EVM values window 5 to an ascii file Results 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard The following example describes a scenario similar to the one for manual operation described in chapter 9 3 Measurement Example 2 Burst GSM EDGE Sign
284. ays Various different result displays for VSA measurements are available Which result types are available depends on the selected data source You can define which part of the measured signal is to be evaluated and displayed The determined result and evaluation ranges are included in the result displays where useful to visualize the basis of the displayed values and traces For background information on the result and evaluation ranges see chapter 4 6 Mea surement Ranges on page 116 e Evaluation Data Sources Im e tet e cene te bic eet to eo ta at cea eec cei ves 14 e Result Types In une cce reno e aac oco resa Haa od 18 e Common Parameters in 5 0 01 44 ne 54 3 1 Evaluation Data Sources in VSA data sources for evaluation available for VSA are displayed in the evaluation bar in SmartGrid mode The data source determines which result types are available see table 3 1 For details on selecting the data source for evaluation see chapter 6 5 Display and Win dow Configuration on page 201 In diagrams in the frequency domain Spectrum transformation see Result Type Transformation on page 202 the usable bandwidth is indicated by vertical blue lines Spectrum RealImag CapBuf usable IQ Bandwidth Start 7 68 MHz Stop 7 68 MHz 15 Measureme
285. bandwidth of the analog IF filter at very high output sample rates the curve breaks e Bandwidth Extension 65 e Relationship Between Sample Rate and Usable Bandwidth 65 e Relationship Between Sample Rate Record Length and Usable 1 0 Bandwidth 65 e R amp S FPS without additional bandwidth extension 66 e R amp S FPS with option B40 1 Bandwidth 67 e R amp S FPS with activated option B160 1 0 Bandwidth Extension 67 4 2 1 1 Bandwidth Extension Options Max usable BW Required B option 40 MHz 40 160 2 160 4 2 1 2 Relationship Between Sample Rate and Usable Bandwidth Up to the maximum bandwidth the following rule applies Usable bandwidth 0 8 Output sample rate MSRA operating mode In MSRA operating mode the MSRA Master is restricted to a sample rate of 600 MHz The figure 4 6 shows the maximum usable I Q bandwidths depending on the output sample rates 4 2 1 3 Relationship Between Sample Rate Record Length and Usable Bandwidth Up to the maximum bandwidth the following rule applies Usable I Q bandwidth 0 8 Output sample rate Regarding the record length the following rule applies Record length Measurement time sample rate Maximum record length for RF inp
286. bols over time pum PIN NDA VO UU User Manual 1176 8516 02 06 42 R amp S FPS K70 Measurements and Result Displays MAG ERR MAG yeas MAG ger 0 with and Tp the duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 1 Mag Error ei Clrw 49 sym Fig 3 15 Result display Magnitude Error Available for source types e Modulation Errors Remote commands LAY ADD 1 BEL MERR to define the required source type see LAYout ADD WINDow page 359 CALC FORM MAGN to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 3 2 25 Phase Error Displays the phase error of the measuremente signal with respect to the reference sig nal as a function of symbols over time PHASE _ERR t PHASE yras PHASE pep t with and duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 User Manual 1176 8516 02 06 43 R amp S FPS K70 Measurements and Result Displays e ____ __ ______________________________________________________________ ees 1 Phase Error Clrw Fig 3 16 Result display Phase Error
287. c Measurement Time Meastime 189 Upper Level 189 Lower Level E tct detect tci c a Hc etd 189 Auto Scale Once Auto Scale Window eee ee ecce eco 189 Aute Scalg A rab edet re ux erai ae 189 Setting the Reference Level Automatically Auto Level Automatically determines the optimal reference level for the current input data At the same time the internal attenuators are adjusted so the signal to noise ratio is opti mized while signal compression clipping and overload conditions are minimized To determine the optimal reference level a level measurement is performed on the R amp S FPS Adjusting Settings Automatically You can change the measurement time for the level measurement if necessary see Changing the Automatic Measurement Time Meastime Manual on page 189 Remote command SENSe ADJust LEVel on page 332 Resetting the Automatic Measurement Time Meastime Auto Resets the measurement duration for automatic settings to the default value Remote command SENSe ADJust CONFigure DURation MODE on page 330 Changing the Automatic Measurement Time Meastime Manual This function allows you to change the measurement duration for automatic setting adjustments Enter the value in seconds Remote command SENSe ADJust CONFigure DURation MODE on page 330
288. can stop and start a new measurement any time Furthermore you can perform a sequence of measurements using the Sequencer see Multiple Measurement Channels and Sequencer Function on page 11 ABORT 332 5 eA e ae 333 INI TIate sn CONTIDUDIS 333 rat I eerte gy e ted ee dct 334 REFM6edAS iai o E Aa 334 INI Tiate sm REFRE Shii eicit nahen oer dra dre pana de aha ves da iR URS 335 INI Tiate nSEQuencerREFResh DALL uacia ttt erect erret ente 335 INITiatesns SEQUencerABOREL erre re deerit a euer een raodo ses rase LESA a AaS 335 lt gt 5 336 lt gt 5 24 444 4 4 336 SYS Tem SEQUENCE enoni dedere eet re ree itte cdd Eia UA 337 ABORt This command aborts the measurement in the current measurement channel and resets the trigger system To prevent overlapping execution of the subsequent command before the measure ment has been aborted successfully use the OPC or command after ABOR and
289. cation whether or not the currently defined line position lies within the analysis interval of the active application remains in the window title bars Parameters lt State gt ON OFF RST ON Analysis CALCulate lt n gt MSRA ALINe VALue Position This command defines the position of the analysis line for all time based windows in all MSRA applications and the MSRA Master lt gt is irrelevant Parameters Position Position of the analysis line in seconds The position must lie within the measurement time of the MSRA measurement Default unit s CALCulate lt n gt MSRA WINDows lt n gt IVAL This command queries the analysis interval for the window specified by the WINDow suffix lt n gt the CALC suffix is irrelevant This command is only available in application measurement channels not the MSRA View or MSRA Master Return values lt IntStart gt Start value of the analysis interval in seconds Default unit s lt IntStop gt Stop value of the analysis interval in seconds Usage Query only SENSe MSRA CAPTure OFFSet Offset This setting is only available for applications in MSRA mode not for the MSRA Master It has a similar effect as the trigger offset in other measurements Parameters lt Offset gt This parameter defines the time offset between the capture buf fer start and the start of the extracted application data The off set must be a positive value as the application can onl
290. ch is indicated by the IF OVLD status display OVLD for digitial baseband input The reference level is also used to scale power diagrams the reference level is then used as the maximum on the y axis Since the hardware of the R amp S FPS is adapted according to this value it is recommen ded that you set the reference level close above the expected maximum signal level to ensure an optimum measurement no compression good signal to noise ratio Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel on page 293 Shifting the Display Offset Reference Level Defines an arithmetic level offset This offset is added to the measured level The scal ing of the y axis is changed accordingly Define an offset if the signal is attenuated or amplified before it is fed into the R amp S FPS So the application shows correct power results All displayed power level results will be shifted by this value The setting range is 200 dB in 0 01 dB steps Note however that the internal reference level used to adjust the hardware settings to the expected signal optimally ignores any Reference Level Offset Thus it is impor tant to keep in mind the actual power level the R amp S FPS must handle and not to rely on the displayed reference level internal reference level displayed reference level offset Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel OFFSet on 293 Set
291. command defines the capture length for further processing e g for burst search The record length is defined in time S default or symbols SYM Note that the maximum record length depends on the sample rate for signal capture see SENSe DDEMod PRATe on page 301 For the default value 4 the maximum is 64000 symbols For larger sample rates the maximum record length in symbols can be calculated as Recordlengthyax 256000 points per symbol Setting parameters lt RecordLength gt numeric value RST 2 083 ms Default unit s not symbols as in manual operation Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Capture Length Settings on page 156 SENSe SWAPiq State This command defines whether or not the recorded IQ pairs should be swapped I lt gt before being processed Swapping and Q inverts the sideband This is useful if the DUT interchanged the and Q parts of the signal then the R amp S FPS can do the same to compensate for it 11 5 4 Configuring VSA Parameters State ON and Q signals are interchanged Inverted sideband Q j l OFF and Q signals are not interchanged Normal sideband j Q RST OFF Manual operation See Swap 1 0 page 157 TRACe n IQ BWIDth This command queries the bandwidth in Hz of the resampling filter Usable Band
292. commands control the Positive TRansition part of a register Setting a bit causes a 0 to 1 transition in the corresponding bit of the associated regis ter The transition also writes a 1 into the associated bit of the corresponding EVENt register Parameters lt BitDefinition gt Range 0 to 65535 lt ChannelName gt String containing the name of the channel The parameter is optional If you omit it the command works for the currently active channel Commands for Compatibility The following commands are maintained for compatibility reasons with previous R amp S analyzers only Use the specified alternative commands for new remote control pro grams CALGulatesn gt F SK DEViation COMPENSATION la ee dan nud 402 SENSe IDDEMod NORMalize VALUue 2 2 22 oorr eru take densa cac 402 SENS ternera rata eec uxo ce dpa 403 CALCulate n FSK DEViation COMPensation lt RefDevComp gt This command defines whether the deviation error is compensated for when calculat ing the frequency error for FSK modulation Note that this command is maintained for compatibility reasons only For newer remote programs use SENSe DDEMod NORMalize FDERror on page 324 Setting parameters lt RefDevComp gt ON OFF 1 0 ON Scales the reference signal to the actual
293. control programs see chapter 11 8 2 Working with Win dows in the Display on page 359 Only for the Equalizer Impulse Response and Equalizer Frequency Response this command is required Configuring the Result Display Setting parameters Feed string XTIM DDEM MEAS Measured signal XTIM DDEM REF Reference signal XTIM DDEM ERR VECT Error vector XTIM DDEM ERR MPH Modulation errors XTIM DDEM MACC Modulation accuracy XTIM DDEM SYMB Symbol table Capture Buffer XTIM DDEM IMP Equalizer Impulse Response XFR DDEM RAT Equalizer Frequency Response XFR DDEM IRAT Equalizer Channel Frequency Response Group Delay CALCulate lt n gt FORMat Format This command defines the result type of the traces Which parameters are available depends on the setting for the data source see LAYout ADD WINDow on page 359 and table 3 1 Whether the result type shows absolute or relative values is defined using the DISP WIND TRAC Y MODE command see DISPlay WINDowcn TRACe t Y SCALe MODE on page 370 Configuring the Result Display Setting parameters Format MAGNitude PHASe UPHase RIMag FREQuency COMP CONS IEYE QEYE FEYE CONF RCONStellation RSUMmary BERate GDELay MOVerview NONE MAGNitude Magnitude Absolute MOVerview Magnitude Overview Absolute entire capture buffer PHASe Phase Wrap UPHase Phase Unwrap RIMag Real Imag
294. crnina eee 198 Peak Search Sets the selected marker delta marker to the maximum of the trace If no marker is active marker 1 is activated Remote command CALCulate lt n gt MARKer lt m gt MAXimum PEAK on page 346 CALCulate n DELTamarker m MAXimum PEAK on page 345 Search Next Peak Sets the selected marker delta marker to the next lower maximum of the assigned trace If no marker is active marker 1 is activated Remote command CALCulate lt n gt MARKer lt m gt MAXimum NEXT on page 346 CALCulate n DELTamarker m MAXimum NEXT on page 345 Peak Sets the active marker delta marker to the largest absolute peak value maximum minimum of the selected trace Remote command CALCulate n MARKer m MAXimum APEak on page 346 Search Minimum Sets the selected marker delta marker to the minimum of the trace If no marker is active marker 1 is activated Remote command CALCulate n MARKer m MINimum PEAK on page 347 CALCulate n DELTamarker m MINimum PEAK on 345 Search Next Minimum Sets the selected marker delta marker to the next higher minimum of the selected trace If no marker is active marker 1 is activated Remote command CALCulate lt n gt MARKer lt m gt MINimum NEXT on page 347 CALCulate n DELTamarker m MINimum NEXT on page 345 6 4 Modulation Accuracy Limit Lines M odulation Accuracy Limit Lines The results of a modulat
295. cs dda ei treten ate deua aaa Ec eme a se peus 324 I SENSe IDDEMOod NORMalize GEI ne enu Rotten 324 1 1 2 1244 ener nns 324 SENSe DDEMod NORMalize FDERT OF 2 1 2221 rtr crore er entr ne 324 325 5 00 RTE 325 SENSe DDEMod NORMalize SRE RIQF 5 ettet acabo rotation eo tere deret 325 SENSe DBEMod OPTimization 2 terreri kae e eher eva 325 SENSe DDEMod SEARCh PATTern S YNG ADTO nitet ere eco tire eet anten eR nca 326 0 5 5 326 SENSe DDEMod ECALc MODE lt EvmCalc gt This command defines the calculation formula for EVM Setting parameters lt EvmCalc gt Manual operation Configuring VSA SIGNal SYMBol MECPower MACPower SIGNal Calculation normalized to the mean power of the reference sig nal at the symbol instants SYMBol Calculation normalized to the maximum power of the reference signal at the symbol instants MECPower Calculati
296. ction of the operating parameter Alpha or BT Formulae Gauss ETSI TS 100 959 V8 3 0 Filter Type Setting Parameter Impulse Response Raised cosine RC Alpha a 2 sin T T h r PX 2 Z 1 4 n T Root raised cosine Alpha a in 1 m RRC 4a a zT Gaussian filter BT i MM 2z pT with 2 6 6 Standard Specific Filters A 6 6 1 Transmit filter EDGE Tx filter ETSI TS 300 959 V8 1 2 Linearized GMSK 3 aite S i7 for 0 lt 1 lt 5 ONS i 0 0 SE E J ae dt 0 40 si else for else t 5T 2 _ 37 2 0 0 lt lt 4 for 47 lt t lt 8T 3131 2 Formulae O t a 2 C t is the impulse response of the EDGE transmit filter A 6 6 2 Measurement Filter EDGE Measurement filters RC filter Alpha 0 25 single side band 6 dB bandwith 90 kHz Windowing by multi plying the impulse response according to the following equation 1 0 lt lt 1 57 1 0 5 1 57 2 257 1 57 lt lt 3 757 0 gt 3 75 The following figure shows the frequency response of the standard specific measure ment filters EDGE HSR Narrow Pulse Magnitude dB 4 D i 02 04 06 08 1 12 14 18 18 2 Frequency in fsymbol Formulae EDGE HSR
297. ctrum VSA Ref Level 4 00 dBm Mod Att 24dB Freq 1 0GHz ResLen SGL Stat Count 10 1 Clrw 5 To change the number of evaluations press the SWEEP key and select Statistic Count Config Select Manual and enter the desired number of evaluations e g 12 When you press RUN SINGLE the VSA application will capture data until 12 evaluations are completed 9 3 Measurement Example 2 Burst GSM EDGE Signals In this measurement example a bursted GSM EDGE signal will be measured and eval uated The goal of this section is to familiarize you with the VSA application features that are relevant specifically for the analysis of bursted signals 9 3 1 Transmitter Settings This section summarizes the necessary transmitter settings It contains a list of the parameters and step by step instructions for the R amp S SMW200A If you are interested in a more detailed description or background information refer to the user manual of the R amp S SMW200A which can be downloaded from the Rohde amp Schwarz website www rohde schwarz com downloads manuals smw200A html Frequency 1GHz Level 0 dBm Standard GSM EDGE Burst with normal symbol rate User Manual 1176 8516 02 06 235 Measurement Example 2 Burst GSM EDGE Signals To define the settings for the R amp S SMW200A 1 Press the PRESET key to start from a defined state 2 Press the FREQ key and enter 1 GHz 3 Press the LEVEL key and enter 0 dBm 4 To d
298. cy If no additional options are installed this is the only available input source Input Frontend Radio Frequency Input Coupling Digital IQ Preamplifier Preview Preview Spectrum RealImag CapBuf Rado FISGQUSINGy Staley cc eco cent edd beer ce helo dates 143 COU io 16 143 Preamplifier option B22 B231 deett n eere e tr es RR RR 143 Radio Frequency State Activates input from the RF INPUT connector Remote command INPut SELect on page 288 Input Coupling The RF input of the R amp S FPS can be coupled by alternating current AC or direct cur rent DC AC coupling blocks any DC voltage from the input signal This is the default setting to prevent damage to the instrument Very low frequencies in the input signal may be dis torted However some specifications require DC coupling In this case you must protect the instrument from damaging DC input voltages manually For details refer to the data sheet Remote command INPut COUPling on 288 Preamplifier option B22 B24 Switches the preamplifier on and off If activated the input signal is amplified by 20 dB If option R amp S FPS B22 is installed the preamplifier is only active below 7 GHz User Manual 1176 8516 02 06 143 5 5 2 Input Output and Frontend Settings If option R amp S FPS B24 is installed the preamplifier is active for all f
299. d i e how much of the signal has been evaluated Mag CapBuf Stop 8000 sym Start 0 sym 2 Press the RUN SINGLE key Since the signal you are currently analyzing is continuous as opposed to contain ing bursts the entire capture buffer is analyzed and hence will be marked with the green bar The last evaluated result range i e the currently evaluated result range at the time the measurement stopped is highlighted in blue Mag CapBuf Start 0 sym Stop 8000 sym 3 To go back to a previously evaluated result range within the same capture buffer press the SWEEP key and then the Select Result Rng softkey By selecting dif ferent result ranges for example using the rotary knob you can move the high lighted blue area through the capture buffer and choose your currently demodula ted result range me A C RV X ee 233 User Manual 1176 8516 02 06 R amp S FPS K70 Measurement Examples Select Result Range x Mag CapBuf 1 Clrw Start 0 sym Stop 8000 sym The results for this range are displayed in the Current column in the Result Sum mary in the eye diagram and in the symbol table Note Generally all Clear Write traces and the are affected by this selection 9 2 5 Averaging Several Evaluations By default all measurement windows are display
300. d prefix for each quadrant Table 4 14 Derivation of QAM mappings a In the following diagrams the symbol mappings are indicated in hexadecimal and binary form 0 41 43 2 1100 1101 1111 1110 1000 1001 1011 1010 Fig 4 30 Constellation diagram for 160 GRAY including the logical symbol mapping hexadeci mal and binary Symbol Mapping 1011 1001 0001 0011 1010 1000 0000 0010 1110 1100 0100 0110 1111 1101 0101 0111 Fig 4 31 Constellation diagram for 16QAM including the logical symbol mapping for EDGE hexa decimal and binary 1011 1001 0010 0011 1010 1000 0000 0001 1101 1100 0100 0110 1111 1110 0101 0111 Fig 4 32 Constellation diagram for 16QAM including the logical symbol mapping for DVB C hexa decimal and binary 11010 11110 01011 0111 Fig 4 33 Constellation diagram for 32QAM including the logical symbol mapping for DVB C hexa decimal and binary Symbol Mapping 001000 001001 001101 001100 e e e 001010 001011 001111 001110 000010 000011 000111 000110 000000 000001 000101 000100 Fig 4 34 Constellation diagram for 64QAM including the logical symbol mapping for DVB C hexa decimal and binary the binary form shows the upper right section of the diagram only 0011010 0011011 0001011 0001010 0011000 0011001 0001001 0001000 0010000 0010001 0010101 0010100 001110
301. d Analyzer In order to perform measurements with the R amp S FPS K70 you require a test transmit ter to emulate a DUT For Measurement Example 2 Burst GSM EDGE Signals the test transmitter needs to be GSM compatible Connect the RF output of the R amp S SMW200A with the RF input of the R amp S FPS Measurement Example 1 Continuous QPSK Signal In this measurement example a continuous QPSK Quadrature Phase Shift Keying signal will be measured and evaluated QPSK is used in several standards such as DVB S2 APCO25 WCDMA CDMA2000 etc For the description characterization of a continuous QPSK signal the following parameters are the most important Carrier Frequency e Level e Symbol Rate Transmit Filter Transmitter Settings This section summarizes the necessary transmitter settings It contains a list of the parameters and step by step instructions for the R amp S SMW200A If you are interested in a more detailed description or background information refer to the user manual of Measurement Example 1 Continuous QPSK Signal the R amp S SMW200A which be downloaded from the Rohde amp Schwarz website www rohde schwarz com downloads manuals smw200A html Frequency 1 GHz Level 0 dBm Modulation QPSK Symbol Rate 1 Msym s Filter Root Raised Cosine with Roll Off 0 35 To define the settings for the R amp S SMW200A 1 Press the PRESET key to start from a defined state N Oo a Bo N
302. d Data 5 Define the Alignment of the result range to the reference source i e whether the result starts at the beginning of the reference source ends with the reference source or is centered with the reference source 6 Optionally define an offset of the result range to the reference source e g to ignore the first few symbols of the captured data 7 Optionally define the number of the symbol which marks the beginning of the ref erence source to change the scaling of the x axis This offset is added to the one defined for the signal description Example Defining the result range In figure 8 2 a result range will be defined for the first 100 symbols of the capture buf fer starting at the second symbol which has the symbol number 1 the capture buffer starts at symbol number 1 the first symbol to be displayed is the second symbol due to the offset 1 1 2 Result Range Alignment and Evaluation Range Result Range Length Result Length 26 042 us Result Range Alignment Reference Alignment Capture Burst Pattern Waveform e Left C center Right Offset sym Symbol Number at Capture Start sym Visualization Fig 8 2 Example Defining the Result Range The result range is indicated by a green bar along the time axis in capture buffer result displays see chapter 4 6 Measurement Ranges on page 116 8 3 How to Analyze the Measured Data Once the d
303. d by a parameter To replace an existing window use the LAYout WINDow lt n gt REPLace command This command is always used as a query so that you immediately obtain the name of the new window as a result Parameters Direction LEFT RIGHt ABOVe BELow lt WindowType gt Type of measurement window you want to add See LAYout ADD WINDow on page 359 for a list of availa ble window types Return values lt NewWindowName gt When adding a new window the command returns its name by default the same as its number as a result Example LAY WIND1 ADD LEFT MTAB Result 2 Adds a new window named 2 with a marker table to the left of window 1 Usage Query only LAYout WINDow lt n gt IDENtify This command queries the name of a particular display window indicated by the lt n gt suffix in the active measurement channel Note to query the index of a particular window use the LAYout IDENtify WINDow 2 command Return values lt WindowName gt String containing the name of a window In the default state the name of the window is its index Usage Query only Configuring the Result Display LAYout WINDow lt n gt REMove This command removes the window specified by the suffix lt n gt from the display in the active measurement channel The result of this command is identical to the LAYout REMove WINDow command Usage Event LAY out WINDow lt n gt REPLace lt WindowType gt T
304. d defines the symbol rate The minimum symbol rate is 25 Hz The maximum symbol rate depends on the defined Sample Rate see chapter 4 2 Sample Rate Symbol Rate and Bandwidth on page 63 Configuring VSA Setting parameters lt SymbolRate gt numeric value Range 25 to 250e6 RST 3 84e6 Default unit Hz Example See chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Symbol Rate on page 137 SENSe DDEMod TFILter ALPHa Alpha This command determines the filter characteristic ALPHA BT The resolution is 0 01 Setting parameters Alpha numeric value Range 0 1 to 1 0 RST 0 22 Default unit NONE Example See chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Manual operation See Alpha BT on page 138 See Alpha BT on page 186 SENSe DDEMod TFILter NAME Name This command selects a transmit filter and automatically switches it on For more information on transmit filters refer to chapter A 3 1 Transmit Filters on page 419 Setting parameters Name string Name of the Transmit filter an overview of available transmit fil ters is provided in chapter A 3 1 Transmit Filters on page 419 Example See chapte
305. d distortions can result in lower EVM values The Demodulation settings are displayed when you do one of the following e Select the Demodulation button from the Overview e Select the Demod Meas Filter softkey from the main VSA menu A live preview of the constellation with the current settings is displayed in the preview area at the bottom of the dialog box The preview area is not editable directly Demodulation settings depend on the used modulation R amp S FPS K70 Configuration Demodulation amp Measurement Filter oe EE Compensate for I Q Offset Amplitude Droop Equalizer State Mode Filter Length Demodulation Advanced Meas Filter I Q Imbalance Symbol Rate Error Reset Equalizer Preview Preview Const I Q Meas amp Ref Start 0 002 Stop 0 002 Fig 5 3 Demodulation settings for PSK MSK and QAM modulation User Manual 1176 8516 02 06 177 R amp S FPS K70 Configuration Demodulation amp Measurement Filter LI E Demodulation Demodulation Advanced Meas Filter LS Compensate for Carrier Frequency Drift FSK Deviation Error Symbol Rate Error Equalizer State Mode Filter Length Reset Equalizer Preview Preview Const Freq Meas amp Ref 1M Clrw Start 21 888 MHz Stop 21 888 MHz Fig 5 4 Demodulation settings for FSK modulation EN e Compensate for PSK MSK ASK
306. d single real iq k f10at32 Data File Format iq tar fwrite fid single imag iq k f10at32 end fclose fid List of Remote Commands VSA SENSe ADJust CONFigure DURatiOn tete een entere re eh pet Rech hn 330 SENSe jADJust CONFIgure DURaltion is rh n cent cer hentai rn de he be ERR DR 330 SENSe ADJust 5 5 331 SENSe ADJust CONFigure HYS Teresis UPPBber rtr ennt reb d rn eo E eaa 331 SENS ADJUSt LEVE D N SENSe DDEMod APSK NSTate 1 SENSe DDEMod ASK NS Fate ene aaa rr en Red d e ve PR ead 5 tete en Corea dO RR CREDE DUE SENSe DDEMod ECALEE MODE iore tht etn ee nr topi to at E RR tne EX x E RS SENSe DBEMod EPRate AU TO neret tree rre eth render o ERR cave Era SENSe DDEMod EPRate VALue SENSE I DDEM d EQUalizer LENG Bice neni SENS DBDEMod EQUaliIzern LOAD ttp tt rete a Pere sb needs SENSe DBDEMod EQUaliZer MODE e ee Ok ede PROF rude iment SENSe DDEMeod EQUalizet IRESet rentrer miren er rrr c en Er SENSe DDBEMod EQUAalizer SAWE eet tate t E e eC rep ra tete SENSe DDEMod EQUalizer STATe
307. data o Note that scaling settings are window specific as opposed to the amplitude settings The scaling settings are displayed when you select the AMPT key and then the Scale Config softkey Input Output and Frontend Settings Amplitude Scale Unit YScale XScale Automatic grid scaling Automatic grid scaling Adjust Settings Scaling according to min and max values Automatic grid scaling All Axes Default Settings Max 1 0 Quantize 101 Scaling according to reference and per div Scaling according to reference and per div Ref Value Ref Value 10 0 dBm Ref Position Ref Position Per Division Per Division 4 Stat Mag CaptureBuffer Fig 5 2 Scaling settings for statistical evaluation For details on the different methods to configure the scaling see chapter 8 3 1 How to Change the Display Scaling on page 223 A visualization of the diagram scaling with the current settings is displayed at the right side of the dialog box Auto Scale Once Auto Scale Window sssssssssssssseeeneeennen en 151 Defining Min arid Max Valies c certc ceto eret o eet 152 Configuring a Reference Point and Divisions cocer ener 152 L Y Axis Reference Vale sakane nnn 152 L Y Axis Reference Position ccccccsssssssssseesessecesesesescsessseesetsnesesesese
308. data in MSRA operating mode In MSRA operating mode only the MSRA Master actually captures data the MSRA applications receive an extract of the captured data for analysis referred to as the application data For the R amp S FPS VSA application in MSRA operating mode the application data range is defined by the same settings used to define the signal cap ture in Signal and Spectrum Analyzer mode In addition a capture offset can be defined i e an offset from the start of the captured data to the start of the application data for vector signal analysis The Capture Buffer displays show the application data of the VSA application in MSRA mode Data coverage for each active application Generally if a signal contains multiple data channels for multiple standards separate applications are used to analyze each data channel Thus it is of interest to know which application is analyzing which data channel The MSRA Master display indicates User Manual 1176 8516 02 06 124 VSA in MSRA Operating Mode the data covered by each application restricted to the channel bandwidth used by the corresponding standard by vertical blue lines labeled with the application name Since the VSA application supports several standards and the standard used by the currently analyzed data is not known the Symbol Rate defined in the Signal Description set tings is used to approximate the channel bandwidth Analysis interval However the individual
309. deviation of the mea surement signal OFF Uses the entered nominal deviation for the reference signal RST 1 SENSe DDEMod NORMalize VALue lt Normalize gt This command switches the compensation of the IQ offset and the compensation of amplitude droop on or off Programming Examples Note that this command is maintained for compatibility reasons only Use the more specific SENSe DDEMod NORMalize commands for new remote control programs see chapter 11 5 8 Demodulation Settings on page 318 Setting parameters lt Normalize gt ON OFF 1 0 OFF No compensation for amplitude droop nor offset ON Compensation for amplitude droop and offset enabled RST 1 SENSe DDEMod SBANd lt SidebandPos gt This command selects the sideband for the demodulation Note that this command is maintained for compatibility reasons only Use the SENS SWAP IQ command for new remote control programs see SENSe SWAPiq on page 302 Setting parameters lt SidebandPos gt NORMal INVerse NORMal Normal non inverted position INVerse Inverted position RST NORMal 11 13 Programming Examples The following examples demonstrate how to perform vector signal analysis in a remote environment These examples are meant to demonstrate the use of the most common remote com mands for vector signal analysis Note that not all commands executed here are actually necessary as they may reflect default settings
310. diagram at any time Markers are configured in the Marker dialog box which is displayed when you do one of the following Inthe Overview select Analysis and switch to the vertical Marker tab e Press the MKR key then select the Marker Config softkey Markers Analysis Markers Marker Settings Search Range Selected State Stimulus Code Domain All Marker Off 22972191 1 Code Domain Power Marker Selected Marke M 195 Marker Stal PAM Ee NE ERAS NAA a Kanaa 195 EE 195 Markor err errr 196 Assigning the Marker to amp uc cia cert rtt xd fecit iiem xcu Ed 196 JU MARO S ODE csse peret tippen ere er et ut L 196 Couple WNdOWS M 196 Selected Marker Marker name The marker which is currently selected for editing is highlighted orange Remote command Marker selected via suffix lt m gt in remote commands Marker State Activates or deactivates the marker in the diagram Remote command CALCulate lt n gt MARKer lt m gt STATe on 341 CALCulate lt n gt DELTamarker lt m gt STATe on 342 X value Defines the position of the marker on the x axis Remote command CALCulate lt n gt DELTamarker lt m gt X 343 CALCulate lt n gt MARKer lt m gt X on page 342 6 3 2 Markers Marker Type
311. diagram show ing only a single value e g the EVM RMS value as a bargraph The same parameters are available as those for which modulation accuracy limits can be defined see Limit Value on page 200 Configuring the Result Display Parameters lt SingleValue gt ALL EVMP PERM MERM CFER RHO IQOF FERM FEP FDER ALL Complete Result Summary EVMR RMS EVM EVMP Peak EVM PERM RMS Phase error PEP Peak phase error MERM RMS Magnitude error MEP Peak magnitude error CFER Carrier frequency error RHO RHO IQOF offset FERM RMS frequency error FEP Peak frequency error FDER FSK deviation error RST ALL Manual operation See Result Summary Individual Results on page 50 DISPlay WINDow lt n gt PRATe AUTO lt DisplayPPSMode gt Defines the number of display points that are displayed per symbol automatically i e according to SENSe DDEMod PRATe on page 301 To define a different number of points per symbol for display use the MANual parameter the DISPlay WINDowcn PRATe VALue command Setting parameters lt DisplayPPSMode gt AUTO MANual RST AUTO Manual operation See Display Points Sym on page 203 Retrieving Results DISPlay WINDow lt n gt PRATe VALue lt DisplayPPS gt This command determines the number of points to be displayed per symbol if manual mode is selected see DISPlay WINDow lt n gt PRATe AUTO on page 369 Th
312. ding on the signal using the pattern can speed up your mea surement considerably and make it more robust against high carrier frequency offsets Make sure that the pattern is suitable for synchronization e g a GSM pattern Remote command SENSe DDEMod SEARCh PATTern SYNC AUTO on page 326 SENSe DDEMod SEARch PATTern SYNC STATe on page 326 Fine Synchronization In addition to the coarse synchronization used for symbol decisions a fine synchroni zation is available to calculate various results from the reference signal e g EVM However when the signal is known to have a poor transmission quality or has a high noise level false symbol decisions are more frequent which may cause spikes in the EVM results To improve these calculations the reference signal can be estimated from a smaller area that includes a known symbol sequence in the input signal In this case the results for the limited reference area are more precise at the cost of less accurate results outside this area Thus the result range should be set to the length of the refer ence area The reference area can be defined either using a pattern or using a known data sequence from a Known Data file If no predefined data sequences are available for the signal the detected data is used by default If Auto mode is selected and a Known Data file has been loaded and activated for use the known data sequences are used Otherwise the detected
313. ding to unstable equalizer impulse responses For time invariant channels the estimation length can be extended using Averaging mode In this case the statistics from all previously deter mined reference signals and measurement signals are averaged to determine the cur rent equalizer function Thus the results of previous sweeps are continuously consid ered to calculate the current equalizer values Averaging is only restarted when the R amp S FPS is switched off or when the user manually resets the equalizer Obviously this method requires a stable input signal for the entire duration of the measurement as otherwise the current equalizer is distorted by previous results This process requires extended calculation time so that the measurement update rate of the R amp S FPS decreases distinctly When the distortions are compensated suffi ciently this averaging process can be stopped The current filter is frozen that means itis no longer changed Keep in mind that in Tracking Averaging mode for sweep counts gt 1 repeated analysis of past result ranges might lead to differing readings The equalizer algorithm is limited to PSK and QAM modulation schemes as the optimi zation criterion of the algorithm is based on minimizing the mean square error vector magnitude Thus it cannot be used for FSK modulation User defined equalizers Instead of tracking equalizer values repeatedly for different input signals you can store existing v
314. e see chapter 9 2 3 Changing the Display Configuration on page 232 3 Press RUN SINGLE The rising and falling edges of the burst in the selected result range are displayed in window 4 You could now add an average trace to evaluate the rising and falling edges further mum EIN User Manual 1176 8516 02 06 240 R amp S FPS K70 Measurement Examples Spectrum VSA Ref Level 4 00 d amp m Std EDGE 8PSK SR 270 833 kHz Att 24 dB Freq 1 0GHz ResLen 200 SGL Stat Count 8 BURST PATTERN A EVM 1Clrw B Result Summary Phase Err RMS Gain Imbalance In I Q Capture Amplitude Droop Start 26 sym i 5 Stop 174 sym j Mag CapBuf D MagAbs Meas amp Ref 1 i I 1 1 1 j Pattern Search Start 0 sym Stop 10000 sym Start 26 sym 87 10 2010 13 32 07 Fig 9 9 Result range that exceeds the burst length 9 3 5 Setting the Evaluation Range In some scenarios such as in Evaluating the Rising and Falling Edges the result range contains symbols that are not supposed to be considered for the EVM or other calculated parameters that are displayed in the Result Summary Thus you would not include them in the evaluation range To change the evaluated data 1 Start from the configuration described in chapter 9 3 4 Evaluating the Rising and Falling Edges on page 240 2 Display the constellation diagram of the signal in window 1 Source Meas amp Ref Signal Result type Constellation see cha
315. e VSA application itself it can also be imported to the application provided it has the correct format Furthermore the evaluated data from the VSA application can be exported for further analysis in external applications For details on importing and exporting I Q data see chapter 7 Data Import and Export on page 206 MMEMory E OADIHIGESTATe iiit nto rae ea eye eve uae desea o 390 gt uuu stu ey net Exe E 390 MMEMBrIy STORSSned OS TATG uere aar ipee LE kel senio a Fox Ta 391 MMEMory LOAD IQ STATe 1 lt FileName gt This command restores data from file The file extension is iq tar Parameters lt FileName gt String containing the path and name of the source file Example MMEM LOAD IQ STAT 1 R_S Instr user data ig tar Loads IQ data from the specified file Usage Setting only Manual operation See Q Import on page 207 MMEMory STORe n IQ COMMent Comment This command adds a comment to a file that contains data The suffix n is irrelevant Parameters Comment String containing the comment 11 11 Status Reporting System Example MMEM STOR IQ COMM Device test 15 Creates a description for the export file MMEM STOR IQ STAT 1 C R_S Instr user data ig tar Stores data and the comment to the specified file
316. e also called ISI free points ISI intersymbol interference If the trans mitter does not provide an ISI free signal after the transmit filter TX filter this condi tion can be fulfilled by signal specific filtering of the analyzer input signal receive filter or Rx filter If an RRC root raised cosine filter is used in the transmitter an RRC fil ter is also required in the analyzer to obtain ISI free points In many PSK systems RRC filters used as transmit and measurement filters To determine the modulation error the measurement signal must be compared with the corresponding ideal signal For this purpose a reference filter is required which is calculated by the analyzer by convolving the coefficient of the transmit filter Tx filter and the meas filter see figure 4 2 If unfiltered signals have to be measured as well e g to determine nonlinear signal distortions no measurement filter is switched into the signal path and the reference filter is identical to the Transmit filter see figure 4 2 In the baseband block diagrams see figure 4 2 the system theoretical transmitter and analyzer filters are shown for PSK and QAM demodulation For the sake of clearness RF stages IF filters and the filter stages of the digital hardware section are not shown For a correct demodulation the following filters have to be accurately specified for the analyzer e Transmit filter filter characteristic of transmitter
317. e complex source signal without inter symbol interference as an X Y plot only the de rotated symbol decision instants are drawn and not connected Available for source types e Meas amp Ref Signal User Manual 1176 8516 02 06 24 R amp S9FPS K70 Measurements and Result Displays 3 2 6 1 Const I Q Meas amp Ref 1M Clrw Fig 3 3 Constellation diagram for QPSK modulated signal Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM CONS to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 3 Polar Diagrams on page 376 Constellation Rotated The complex source signal as an X Y plot As opposed to the common Constellation display the symbol decision instants including the rotated ones are drawn and not connected Available for source types e Meas amp Ref Signal This result type is only available for signals with a rotating modulation User Manual 1176 8516 02 06 25 R amp S FPS K70 Measurements and Result Displays 1 ConstRot I Q Meas amp Ref IMG 2 Const I Q Meas amp Ref Fig 3 4 Result display Constellation Rotated vs common Constellation for 377 4 QPSK modulation Remote commands LAY ADD 1 BEL MEAS to define the
318. e for FSK modulation only Setting parameters lt LimitValue gt numeric value the value x x gt 0 defines the interval x x Range 0 0 to 100 RST 1 5 mean 1 0 Default unit Hz User Manual 1176 8516 02 06 352 R amp S FPS K70 Remote Commands for VSA ss a CALCulate lt n gt LIMit MACCuracy MERRor PCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy MERRor PMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy MERRor PPEak VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy MERRor RCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy MERRor RMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy MERRor RPEak VALue lt LimitValue gt This command defines the value for the current peak or mean magnitude error peak or RMS limit Note that the limits for the current and the peak value are always kept identical Setting parameters lt LimitValue gt numeric value the value x x gt 0 defines the interval x x Range 0 0 to 100 RST 1 5 Default unit CALCulate n LIMit MACCuracy OOFFset CURRent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy OOFFset MEAN VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy OOFFset PEAK VALue lt LimitValue gt This command defines the upper limit for the current peak or mean offset Note that the limits for the current and the peak value are always kept identical
319. e measurement channel are stored upon exiting and restored upon re entering the channel Thus you can switch between applications quickly and easily Apart from these settings the following default settings are activated directly after a measurement channel has been set to or after a Preset Channel Table 5 1 Default settings for VSA channels Parameter Value Digital standard 3G_WCDMA Sweep mode CONTINUOUS Trigger settings FREE RUN Trigger offset 0 Modulation QPSK WCDMA mapping Transmit filter RRC a 0 22 Measurement filter Transmit filter Signal type Continuous no pattern Symbol rate 3 84 MHz Sample rate 4 Symbol rate 15 36 MHz Capture length 8000 symbols Usable Bandwidth 12 228 MHz Result length 800 symbols Result Range alignment Left at capture buffer start Configuration According to Digital Standards Parameter Value Evaluation range Entire result range Demodulation Compensation for offset and amplitude droop Estimation points per symbol auto 1 Evaluations Window 1 Constellation 1 Meas amp Ref Window 2 Result Summary Window 3 Magnitude absolute Capture buffer Window 4 Symbol table hexadecimal Display points per symbol Sample rate 4 Apart from the Preset Channel function see Preset Channel on page 133 the fol lowing functions are available to restore factory settings to
320. e minimum burst length to 50 and the maximum burst length to 5000 For more information see Burst Settings on page 140 Burst Configuration on page 166 e The signal is highly distorted and or has modulation noise One possibility to enhance the robustness of the burst search is to increase the minimum gap length If the bursts within your capture buffer are not closely spaced it makes sense to increase the value of this parameter Burst amp Pattem Search Burst amp Pattern Search Scarch S N Auto according to Signal Description Burst found Auto according to Signal Description Burst found Meas only if Burst was found Meas only if Burst was found Auto Configurabon Auto Configurabon Search Tolerance 4 sym 14 769 ys Search Tolerance 4 sym 14 769 us Min Length 3 692 us Min Length 10 sym 3 36 923 us Related Settings Related Settings Signal Description Signal Description Trace Mag CapBuf 1 Cir Mag CapBuf Fig 10 6 Example for adjusting the minimum gap length For more information see Min Gap Length on page 166 The pattern search is switched on fails and the alignment is with reference to the pattern In case the pattern search is switched on and the reference for the alignment is the pattern and not the burst a non detected pattern causes the result range to be positioned at the beginning of the capture buffer Hence if a the burst does not start
321. e parameter is optional If you omit it the command works for the currently active channel STATus QUEStionable ACPLimit PTRansition lt BitDefinition gt ChannelName STATus QUEStionable DIQ PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable FREQuency PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable LIMit lt m gt PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable LMARgin lt m gt PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt CFRequency PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt EVM PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt FSK PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt IQRHo PTRansition BitDefinition lt ChannelName gt STATus QUEStionable MODulation lt n gt MAGNitude PTRansition BitDefinition lt ChannelName gt User Manual 1176 8516 02 06 401 11 12 Commands for Compatibility STATus QUEStionable MODulation lt n gt PHASe PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable POWer PTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable SYNC PTRansition lt BitDefinition gt lt ChannelName gt These
322. e threshold Auto option is enabled the default value of 9096 is used As long as the pattern is found there is no need to change this parameter However if the pattern is very short approximately 10 symbols or if the signal is highly distorted tuning this parameter helps the pattern search to succeed To define a threshold manually dis able the Auto option Remote command SENSe DDEMod SEARch SYNC IQCThreshold on page 311 SENSe DDEMod SEARch PATTern CONFigure AUTO on page 310 Meas only if Pattern Symbols Correct If enabled measurement results are only displayed and are only averaged if a valid pattern has been found When measuring signals that contain a pattern and are aver aged over several measurements it is recommended that you enable this option so that erroneous measurements do not affect the result of averaging Remote command SENSe DDEMod SEARch SYNC MODE on page 311 Selected Pattern for Search Indicates which of the patterns that are assigned to the current standard is selected and will be searched for The selected pattern is indicated for information only and cannot be edited here only in the Signal Structure settings see Name on page 140 Remote command SENSe DDEMod SEARch SYNC SELect on page 312 Pattern Found Indicates whether a pattern was found in the currently captured data 5 7 3 Pattern Configuration For common signal standards the patterns to be searched fo
323. e trigger settings define the beginning of a measurement The Trigger settings are displayed when you do one of the following Select the Signal Capture button from the Overview Select the Signal Capture softkey from the main VSA menu Then switch to the Trigger tab R amp S9FPS K70 Configuration Capture VSA Data Acquisition Trigger Level i Offset 0 0 sym Hysteresis Drop Out Time Slope Tu Fano Holdoff Time Preview Preview Mag CapBuf Start 0 sym The TRIGGER INPUT OUTPUT connectors on the R amp S FPS can only be used for input in the VSA application for use as external triggers No configuration settings are available for trigger input For step by step instructions on configuring triggered measurements see the R amp S FPS User Manual MSRA operating mode 2 In MSRA operating mode only the MSRA Master channel actually captures data from the input signal Thus no trigger settings are available in the VSA application in MSRA operating mode However a capture offset can be defined with a similar effect as a trigger offset It defines an offset from the start of the captured data from the MSRA Master to the start of the application data for vector signal analysis See Capture Off set For details on the MSRA operating mode see the R amp S FPS MSRA User Manual 7 159 2 2 159 L External
324. ear Write and View are available For the Magnitude Absolute result display the trace modes Average MinHold MaxHold are applied to the individual result ranges and thus may not provide useful results Clear Write Overwrite mode the trace is overwritten by each measurement This is the default setting Trace Settings Max Hold The maximum value is determined over several measurements and displayed The R amp S FPS saves each trace point in the trace memory only if the new value is greater than the previous one Min Hold The minimum value is determined from several measurements and displayed The R amp S FPS saves each trace point in the trace memory only if the new value is lower than the previous one Average The average is formed over several measurements The Statistic Count determines the number of averaging procedures View The current contents of the trace memory are frozen and displayed Blank Removes the selected trace from the display Remote command DISPlay WINDow lt n gt TRACe lt t gt MODE on page 339 Evaluation Defines whether the trace displays the evaluation of the measured signal or the refer ence signal if Meas amp Ref Signal is used as the evaluation data source see Signal Source on page 202 Remote command CALCulate lt n gt TRACe lt t gt VALue on page 338 Predefined Trace Settings Quick Config Commonly required trace settings have been predefined and can be applied ver
325. earched for an pattern by trying different time and frequency hypotheses The pattern is generated inter nally based on the specified symbol number of the pattern and the signal description R amp S FPS K70 Measurement Basics i e modulation scheme and transmit filter The pattern search can also be refer red to as the I Q waveform An 1 pattern is considered detected if the correlation met ric i e the correlation value between the ideal pattern and capture buffer exceeds a specified I Q Correlation Threshold see Correlation Threshold on page 167 If the burst search is switched on the pattern search only searches the pattern in bursts previously detected by the burst search Furthermore it only finds the first pattern within each burst If the burst search is switched off the pattern search searches for the pattern in the entire capture buffer The first detected pattern in the capture buffer for the current pattern search settings is indicated by a green line in the preview area of the Pattern Search configuration dia log box see chapter 5 7 2 Pattern Search on page 166 Information Selected pattern for Search GSM_TSCO Pattern Found X Preview Preview Mag CapBuf 1 Clrw Start 0 sym Stop 1500 sym Predefined Patterns Common standards usually have predefined pattern lists with standard specific pat terns Patterns required for the current
326. easurement values to the right of the current marker posi tion Usage Event CALCulate lt n gt DELTamarker lt m gt MINimum NEXT This command moves a marker to the next higher minimum value Usage Event Manual operation See Search Next Minimum on page 198 CALCulate lt n gt DELTamarker lt m gt MINimum PEAK This command moves a delta marker to the minimum level If the marker is not yet active the command first activates the marker Usage Event Manual operation See Search Minimum on page 198 Analysis CALCulate lt n gt DELTamarker lt m gt MINimum RIGHt This command moves a delta marker to the next higher minimum value The search includes only measurement values to the right of the current marker posi tion Usage Event CALCulate lt n gt MARKer lt m gt MAXimum APEak sets the marker to the largest absolute peak value maximum or minimum of the selected trace Usage Event Manual operation See Max on page 198 CALCulate lt n gt MARKer lt m gt MAXimum LEFT This command moves a marker to the next lower peak The search includes only measurement values to the left of the current marker posi tion Usage Event CALCulate lt n gt MARKer lt m gt MAXimum NEXT This command moves a marker to the next lower peak Usage Event Manual operation See Search Next Peak on page 198 CALCulate lt n gt MARKer lt m gt MAXimum RIGHt This command moves a marker to the next lower peak
327. ed Any referen ces to the known data in the Demodulation dialog box are replaced by the default parameter values see chapter 5 9 2 Advanced Demodulation Synchronization on page 180 Note When a standard is loaded the use of a Known Data file is automatically deacti vated Remote command SENSe DDEMod KDATa STATe on page 323 Load Data File If Known Data is activated this function displays a file selection dialog box to select the xml file that contains the known data Once a file has been selected any additional information provided by the file is displayed at the bottom of the dialog box Remote command SENSe DDEMod KDATa NAME on page 324 5 5 Input Output and Frontend Settings The R amp S FPS can evaluate signals from different input sources The frequency and amplitude settings represent the frontend of the measurement setup Lulu CRIMES 142 OUPO SENGS Ep eie Oe ese 144 e Frequency 146 e Amplitude and Vertical Axis 147 5 5 1 Input Settings Input settings can be configured via the INPUT OUTPUT key in the Input dialog box Some settings are also available in the Amplitude tab of the Amplitude dialog box e Rado Frequency ont perra 1 143 R amp S FPS K70 Configuration SSS eS ee 5 5 1 1 Radio Frequency Input The default input source for the R amp S FPS is the radio frequen
328. ed see chapter 5 2 Configuration According to Digital Standards on page 129 The most common measurements are predefined as standard settings for a large num ber of mobile radio networks The instrument comes prepared with the following set tings for those standards Capture length and result length Signal description e Modulation e Transmit filter and measurement filter e Burst Pattern search configuration Result range alignment Evaluation range settings Display configuration The standard settings are grouped in folders to facilitate selecting a standard s WIO ous e Jo pJepueis sJeyllp si 104 425 991 x Predefined Standards and Settings _ 451 3903 WvoO9L 7 YSN 3903 2 0081 ASNS 3904 Wy GLivvl e weyed Srl 3903 WVO9L pezueeur ZHM 228 022 9 99 3903 13snqjeuu 3983 251 2008 YSN 39d3 aN 3933 _ 7 3983 E N GLivvl e weyed 871 0061 3903 7 pezueeur 2 228 022 548 8 548 3903 cav WSS 8v Ws9 7 ANON ZH WSS ysungss 98 8 weed 98 WSS 0 MSND 22228 022 MSIAG WS9 84 WS9 jsung 191095 Logs ISO 3NON ZH INSO vvL S9 J 0 MSND lt 80 2 314 159 ZIENS aS 159 m jsunguon
329. ed with a single trace which is the Clear Write trace This trace displays the result of the current evaluation i e the high lighted blue area from the example in chapter 9 2 4 Navigating Through the Capture Buffer on page 233 However for most real world measurement tasks you need to obtain a result that is averaged over a certain number of evaluations or a worst case result of a certain number of evaluations This section explains how to achieve this To evaluate EVM vs Time 1 Configure window 1 such that it displays the EVM versus time measurement Source Error Vector Result Type EVM see chapter 9 2 3 Changing the Dis play Configuration on page 232 Select the window to set the focus on it 2 To display the trace averaged over several measurements or the maximum hold trace over several measurements press the TRACE key 3 Add further traces by pressing the TRACE key and then either using the Trace 2 3 or the Trace Config softkeys Set the second trace to Average and the third trace to Max Hold Note that the configured traces appear in the window title pum EIN User Manual 1176 8516 02 06 234 R amp S FPS K70 Measurement Examples Start 0 sym i Stop 800 sym Fig 9 4 Several traces in one window 4 Press RUN SINGLE again The current capture buffer is evaluated for this trace setup In the channel informa tion bar you can see the number of completed evaluations Stat Count Spe
330. eeaes 152 C Range ata 152 AAKS 152 E I pc o NENNEN PE 153 Eau SEND s casas ot cnn no 153 o 153 L X Axis Reference ValUe ssccssssesssssescscscsessessesseeseseseseseseseecesseenetsceneesenes 153 L X Axis Reference 24 0141 153 L Range per DIVISION rnit teta aceti dto end add prd 153 Auto Scale Once Auto Scale Window If enabled both the x axis and y axis are automatically adapted to the current mea surement results only once not dynamically in the selected window adapt the range of all screens together use the Auto Scale All function Remote command DISPlay WINDowcn TRACe t Y SCALe AUTO ONCE on page 330 Input Output and Frontend Settings Defining Min and Max Values Indicates the current range borders according to the current settings for information only For statistical evaluations only defines the displayed range using minimum and maximum values Values in the range 1e value 0 1 are allowed The y axis unit is defined via the Y Axis Unit on page 154 setting The distance between max and min value must be at least one decade Remote command CALCulate lt n gt STATistics SCALe Y UPPer page 297 CALCulate n STATistics SCALe Y LOWer on
331. eference level This corresponds approximately to the peak envelope power of the signal Start the VSA application by pressing the MODE key and then selecting VSA Select the Overview softkey to display the Overview for VSA Press the MEAS key then select the Digital Standards softkey 209 Gr X From the file selection list select the GSM folder and then the file EDGE 8PSK Select Load Predefined settings corresponding to the selected standard are loaded The VSA application should show good measurement results Spectrum VSA Ref Level 4 00 dBm Std EDGE 8PSK SR 270 833 kHz m el Att 20 4dB Freq 1 0GHz Cap Len 1500 BURST PATTERN 1 Clrw Result Summary Phase Err RMS Carrier Freq Err Gain Imbalance V Power MN Start 0 sym Stop 148 sym C Mag CapBuf 1 Clrw D Symbol Table H Start 0 sym Fig 9 6 Default display configuration for GSM 8PSK EDGE 8 In window 3 you see the currently evaluated burst marked with a green bar To include more bursts in the display you need to increase the capture length a Press the MEAS CONFIG key and then the Overview softkey b Select Signal Capture C Increase the Capture Length e g to 10000 symbols In the preview area of the dialog box you see that more bursts are now contained in the capture buffer They are all marked with a green bar meaning that they are all evaluated User Manual 1176 8516 02 06 238
332. efine the standard Select the Baseband A block b Under TSMA standards select GSM EDGE 5 To configure the burst type in the GSM EDGE A dialog box a In the Framed Single Configuration tab highlight the first slot in the frame diagram Frame Select Slot To Configure Fig 9 5 R amp S SMW200A GSM EDGE frame configuration settings Measurement Example 2 Burst GSM EDGE Signals b In the GSM EDGE A Burst Slot0 dialog box select the Burst Type Nor mal 8PSK EDGE GSM EDGE A Burst Slot0 e Save Recall Slots Slot Level Full Slot Attenuation dB A1 Multislot Configuration Number Of Slots 174 174 C Close the GSM EDGE Burst Slot0 dialog box 6 Inthe General tab toggle the State to On to switch the modulation on 7 Close the GSM EDGE dialog box 8 Select the RF A signal output to switch the RF transmission on 9 3 2 Analyzer Settings This section helps you get your first valid measurement with a bursted signal It starts with step by step instructions and continues with a more detailed description of further functionality Frequency 1 GHz Ref Level 4dBm Standard GSM 8PSK EDGE To define the settings on the R amp S FPS 1 Press the PRESET key to start from a defined state 2 Press the FREQ key and enter 7 GHz R amp S FPS K70 Measurement Examples 3 Press the AMPT key and enter 4 dBm as the r
333. efined for each result type Depending on the modulation type different result types are available Result type Remote command PSK MSK QAM EVM RMS CALCulate n LIMit MACCuracy EVM RCURrent VALue on page 352 EVM Peak CALCulate n LIMit MACCuracy EVM PCURrent VALue on page 352 Phase Err Rms CALCulate n LIMit MACCuracy PERRor RCURrent VALue on page 353 Phase Err Peak CALCulate lt n gt LIMit MACCuracy PERRor PCURrent VALue on page 353 Magnitude Err Rms CALCulate n LIMit MACCuracy MERRor RCURrent VALue on page 353 Magnitude Err Peak CALCulate n LIMit MACCuracy MERRor PCURrent VALue on page 353 Carr Freq Err CALCulate n LIMit MACCuracy CFERror CURRent VALue on page 351 Rho CALCulate n LIMit MACCuracy RHO CURRent VALue on page 354 IQ Offset CALCulate n LIMit MACCuracy OOFFset CURRent VALue on page 353 FSK modulation only Freq Err Rms CALCulate n LIMit MACCuracy FERRor RCURrent VALue on page 352 Freq Err Peak CALCulate n LIMit MACCuracy FERRor PCURrent VALue on page 352 6 5 Display and Window Configuration Result type Remote command Magnitude Err Rms CALCulate lt n gt LIMit MACCuracy MERRor RCURrent VALue on page 353 Magnitude Err Peak CALCulate lt n gt LIMit MACCuracy MERRor PCURrent VALue on page 353 FSK Dev Err CALCulate lt n gt LIMit MACCuracy FERRor PCU
334. em nennen rennen nnne nnne 399 STATus QUEStionable DIQ ENABle S TATUs QUEStionable DIQ NTRATSITOE coa er crore x eo 400 STATus QUEStionable DIQ P T RansitlOh iar tu torrenti EAEE nix eua un PEE pr n 401 STATUus QUEStiornable DIQ EVENI ctci rere need utes vio D tpe te d 399 STATus QUEStionable FREQuency CONDition STATus QUEStionable EREQu ency ENABIe rt ton rrt pete ER HER EXT STATus QUEStionable FREQuency NTRansition 1 ttt tern rnt tere err nn 400 STATus QUEStionable FREQuency P TRansitioh oen ttn intr tenete nta tini ao cars 401 STATus QUEStionable FREQuency EVENItJ esses enne nennen nnne nnne nennen enne 399 STATUs QUEStionable LIMitsm EEMENI J estera e ettet cig teen 399 lt gt 399 STATus QUEStionable LIMit lt m gt ENABle STATus QUEStionable LIMit lt m gt NTRansition lt gt nennen nnne nenne 401 5 lt gt 2 20 0 399 5 lt lt gt
335. ement mode to continuous measurement Manual operation See Continuous Sweep RUN CONT on page 161 INITiate lt n gt IMMediate This command starts a single new measurement For a statistics count gt 0 this means a restart of the corresponding number of mea surements With trace mode MAXHold MINHold and AVERage the previous results are reset on restarting the measurement You can synchronize to the end of the measurement with OPC OPC WAI For details on synchronization see the Remote Basics chapter in the R amp S FPS User Manual Suffix n irrelevant Usage Event Manual operation See Single Sweep RUN SINGLE on page 162 INITiate REFMeas Repeats the evaluation of the data currently in the capture buffer without capturing new data This is useful after changing settings for example filters patterns or evaluation ranges Usage Event Manual operation See Refresh non Multistandard mode on page 162 Performing a Measurement INITiate lt n gt REFResh This function is only available if the Sequencer is deactivated SySTem SEQuencer SYST SEQ OFF and only for applications in MSRA mode not the MSRA Master The data in the capture buffer is re evaluated by the currently active application only The results for any other applications remain unchanged The suffix lt n gt is irrelevant Example SYST SEQ OFF Deactivates the scheduler INIT CONT OFF Switches to single sweep mode
336. emote command DISPlay WINDowcn TRACe SYMBol on page 370 Display Points Sym Defines the number of display points that are displayed per symbol If more points per symbol are selected than the defined Sample Rate the additional points are interpola ted for the display The more points are displayed per symbol the more detailed the trace becomes For more information see chapter 4 7 Display Points vs Estimation Points per Sym bol on page 121 Note If the capture buffer is used as the signal source the Sample Rate defines the number of displayed points per symbol the Display Points Sym parameter is not available If Auto is enabled the Sample Rate value is used Alternatively select the number of points to be displayed per symbol manually The available values depend on the source type 17 only the symbol time instants are displayed 2 4 8 16 more points are displayed than symbols 32 Capture Oversampling the number of samples per symbol defined in the signal capture set tings are displayed see Sample Rate on 156 Remote command DISPlay WINDow lt n gt PRATe VALue on page 370 DISPlay WINDow lt n gt PRATe AUTO on page 369 Oversampling Defines the sample basis for statistical evaluation This setting is only available for the result type transformation Statistics 6 6 Zoom Functions Ref Level 10 00 Std GSM NormalBurst SR 270 833 kHz Att 30 dB Freq 15 0 GHz Re
337. ences i e lt Data gt elements can be defined in total lt RS_VSA_KNOWN_DATA_FILE gt as specified File End the exact number also depends on available memory space Sample xml file for known data lt RS VSA KNOWN DATA FILE Version 01 00 gt Comment Standard EDGE 8PSK Base 16 lt ModulationOrder gt 8 lt ResultLength gt 148 lt Data gt 777 511 727 242 206 Data Data Data 7 Data 77 770 173 705 631 011 177 177 171 117 777 527 046 104 004 106 241 264 773 1 337 231 35 770 17 177 17 527 04 241 26 727 242 206 705 631 011 171 117 777 104 004 106 773 1 337 4 0 1 7 511 727 242 206 770 173 705 631 011 177 177 171 117 777 527 046 104 004 106 241 264 773 1 331 777 511 727 242 206 770 173 705 631 011 177 177 171 117 777 527 046 104 004 106 241 264 773 1 331 777 511 727 242 206 lt Comment gt lt Base gt lt ModulationOrder gt lt ResultLength gt 341 366 632 073 607 235 507 476 330 522 177 717 717 111 615 047 125 415 723 344 446 514 600 677 7 lt Data gt 341 366 632 073 607 235 507 476 330 522 177 717 717 111 615 047 125 415 723 344 446 514 600 677 7 7 Data 341 366 632 073 607 235 507 476 330 522 177 717 717 111 615 047 125 415 723 344 446 514 600 677 7 77 Data 341 366 632 073 607 235 507 476 330 522 177 717 717 111 615 047 125 415 723 344 446 514 600 677 Data 341 366 632 073 607 A 6
338. ency phase and timing synchronization have been achieved e the reference signal i e the symbols that have been determined in the demodu lator and have already been filtered with the Transmit filter For FSK the measurement filter filters the instantaneous frequency of the signal not the signal For MSK PSK QAM and User QAM the measurement filter filters the real part and imaginary part of these signals i e not the instantaneous frequency or magnitude of the signal The application defines the error signal as the difference between the reference signal and the measurement signal Thus the measurement filter also shapes the spectrum of the error signal which is used to calculate the EVM for example In many applications the measurement filter is the same as the RX filter However unlike the measurement filter the RX filter is not relevant for the measurement but is only required to create the reference signal optimally The RX filter and the transmit filter are usually chosen such that their combination results an Inter Symbol Interference ISI free system see figure 4 2 and figure 4 3 Set by user 7777 Symbols 4 DUT Transmitter Filters and Bandwidths During Signal Processing Auto Auto Function of TX Filter fct CaptureOV sph symbol rate Symbols bits Demodulation filter of IQ capture 8 symbol with Dp decision
339. er 02 015 Phase ae amp o 3 915 925 38 34 42 X 4 2 0 Power 029 Phase Tianster F unetoe Anayzer 02 015 Phase I e b e m o ee e 9 amp 14 2 0 6 5 4 3 Input Power A logarithmic display of the phase transfer functions is shown in table 4 20 The ana lyzer trace is shifted by the phase described above as against the transmitter trace Signal Model Estimation and Modulation Errors Mele uw EA fia 5p mua ges t Logs 1 P gj Imaginary Fig 4 58 Additive noise A 64QAM signal with additive noise is shown in figure 4 58 only the first quadrant is shown The symbol decision thresholds are also shown The noise signal forms a cloud around the ideal symbol point in the constellation dia gram Exceeding the symbol decision boundaries leads to wrong symbol decisions and increases the bit error rate Similar displays are obtained in case of incorrect transmitter filter settings When an incorrect filter is selected crosstalk occurs between neighbouring symbol decision points instead of the ISI free points The effect increases the more the filtering deviates from actual requirements The two effects described cannot be distinguished in the Constellation I Q diagram but in statistical and spectral analyses of the error signal Channel transmission distortion
340. er vsa Standards Note Saving instrument settings in secure user mode In secure user mode all data is stored to volatile memory and is only available during the current instrument session As soon as the power is switched off on the R amp S FPS the data is cleared To store settings permanently select an external storage location such as a USB memory device For details see Protecting Data Using the Secure User Mode in the Data Manage ment section of the R amp S FPS User Manual New Folder Digital Standards Creates a new folder in the file system in which you can save the settings file File Name Digital Standards Contains the name of the data file without the path or extension By default the name of a settings file consists of a base name followed by an under score Multiple files with the same base name are extended by three numbers e g limit lines 005 Configuration According to Digital Standards For details on the file name and location see the Data Management topic in the R amp S FPS User Manual Note Secure user mode In secure user mode settings that are to be stored on the instrument are stored to volatile memory To store data permanently select an external storage location such as a USB memory device For details see Protecting Data Using the Secure User Mode in the Data Manage ment section of the R amp S FPS User Manual Comment Digital Standards An optional description for the dat
341. erence for result range 174 Result Ype 15 Capture Buffer DI ry 121 Capture length Data acquisitiOhi occurrant erre en ren aunt 156 Ir 12 Capture offset MSRA applications coo snes d Capture oversampling 6 63 Capture ranges erre rere 122 Carrier frequency drift eror eir d 179 Definition Formula Carrier frequency error el nN al Ga tle yeh Center frequency Softkey Step SIZE Channel bandwidth MSRAUMOdG ioni tees gd 124 Channel Frequency Response Group Delay Result type eret te rtr 22 Channel Frequency Response Magnitude PRESUME type cnet ert trente eae 22 Closing Channels remote eerte edges Windows remote Coarse Synchronization Compatible o repel eset a esie d tz 170 Compensation Dermodulatiom Modulation errors REMOTE em Constellation Frequency result type 23 Constellation I Q Result type nere merenti 24 Rotated Resulttype 25 Constellation points Symbol MAPPING rere ee breeds 67 Continue single sweep Softkey Continuous signal Continuous sweep S
342. ern Search on page 92 4 4 5 Overview of the Demodulation Process Patter Symbol Check Settings 1213 0 0 1 32 213101011312 101313127911 61211111312 0 270 Fig 4 46 Pattern Symbol Check algorithm The Equalizer A possible source of high modulation errors of the DUT with PSK and QAM signals is a non flat frequency response or ripple in frequency response within the modulation bandwidth This could be caused by the DUT s Analog filter sections Digital filter sections if a shortened filter length is used e Digital arithmetic sections if a shortened bit length is used R amp S FPS K70 Measurement Basics Analyzer DUT Meas Demodulation TX Analog MEAS IQ Meas Filter Filter Filter Signal Error of Transfer Function Fig 4 47 General processing in the modulation and demodulation stages An equalizer filter with a reverse frequency response characteristic is able to compen sate less distorted frequency responses in order to improve the modulation analysis results see figure 4 48 Analyzer BUT Meas Demodulation TX E Analog N m MEAS b IQ Meas Filter Filter Filter Signal Compensation Function Error of Transfer Function Fig 4 48 Compensation of the transfer function s error by inserting an equalizer in the receive path For small distortions the reference signal can be determined correctly without pre equalization The equalizer can be calculated by compar
343. ern Symbol Check This stage performs a bit by bit comparison between the selected pattern and the demodulated bits It is important to note that this comparison is only performed at posi tions that have been identified by the pattern search as possible pattern positions The algorithm and a simple example are illustrated in figure 4 46 First the pattern candidate bits are extracted from the whole bitstream calculated by the Demodulation amp Symbol Decisions stage This means that the symbol stream is cut at the position that has been detected by the 1 0 Pattern Search as the start of the pattern The extracted sequence is then compared to the selected pattern If the demodulation has been ambiguous with respect to the absolute phase position the extracted sequence needs to be compared to all possible rotated versions of the selected pattern For example in the case of QPSK modulation the rotational symme try has the order four i e there are four pattern hypotheses If the extracted sequence coincides with one of the hypotheses the pattern is declared as found and the abso lute phase corresponding to the appropriate hypothesis is passed on Both the symbol decisions and the measurement signal are then rotated with this pattern phase for the whole result range thus resolving the phase ambiguity For more information refer to chapter 4 4 3 Demodulation and Symbol Decisions on page 93 chapter 4 4 2 I Q Patt
344. es information about limit violations in Carrier Frequency evalua tion It can be queried with commands STATus QUEStionable MODulation lt n gt CFREQuency CONDition and STATus QUEStionable MODulation lt n gt CFREQuency EVENt Bit No Meaning 0 Error in current value 1 Error in mean value 2 Error in peak value 3 15 These bits are not used 11 11 7 STATus QUESTionable MODulation n IQRHO Register This register comprises information about limit violations in offset or RHO evalua tion It can be queried with commands STATus QUEStionable MODulation lt n gt IQRHO CONDition and STATus QUEStionable MODulation lt n gt IQRHO EVENt Bit No Meaning 0 Error in current RHO value 1 Error in mean RHO value 2 Error in peak RHO value 3 4 These bits are not used 5 Error in current 1 offset value 6 Error in mean 1 offset value Status Reporting System Bit No Meaning 7 Error peak 1 offset value 8 15 These bits are not used 11 11 8 STATus QUESTionable MODulation n FSK Register This register comprises information about limit violations in FSK evaluation It can be queried with commands STATus QUEStionable MODulation lt n gt FSK CONDition and STATus QUEStionable MODulation lt n gt FSK EVENt Bit No Meaning 0 Error in current Fre
345. es the search limit function on CALC MARK X SLIM RIGH 20MHz Sets the right limit of the search range to 20 MHz Manual operation See Search Limits Left Right on page 197 CALCulate lt n gt MARKer lt m gt X SLIMits STATe State This command turns marker search limits on and off for all markers in all windows lt gt n are irrelevant If you perform a measurement in the time domain this command limits the range of the trace to be analyzed Analysis Parameters State RST OFF Example CALC MARK X SLIM ON Switches on search limitation Manual operation See Search Limits Left Right on page 197 11 7 3 Configuring Modulation Accuracy Limit Lines The results of a modulation accuracy measurement can be checked for violation of defined limits automatically Manual configuration of limit lines is described in chapter 6 4 Modulation Accuracy Limit Lines on page 199 General Commiands ed eee 349 e Defining se eee e e I 350 11 7 31 General Commands The following commands determine the general behaviour of the limit line check lt gt 11 1 1 1 1 4 ainsi nnn nnn nnn 349 lt gt _1 349 CAL
346. escription of general functions to import and export raw measurement data How to Perform Measurements in VSA The basic procedure to perform each measurement and step by step instructions for more complex tasks or alternative methods e Measurement Examples Detailed measurement examples to guide you through typical measurement sce narios and allow you to try out the application immediately Optimizing and Troubleshooting the Measurement Hints and tips on how to handle errors and optimize the test setup Remote Commands for VSA Remote commands required to configure and perform VSA measurements in a remote environment sorted by tasks Commands required to set up the environment or to perform common tasks on the instrument are provided in the main R amp S FPS User Manual Programming examples demonstrate the use of many commands and can usually be executed directly for test purposes Annex Reference material List of remote commands Alpahabetical list of all remote commands described in the manual Documentation Overview Index 1 2 Documentation Overview The user documentation for the R amp S FPS consists of the following parts Printed Getting Started manual Online Help system on the instrument Documentation CD ROM with Getting Started User Manuals for base unit and firmware applications Service Manual Release Notes Data sheet and product brochures Online Help The Online He
347. eshold Specify the expected position of the pattern within the burst by adjusting the Offset parameter Message Sync Prefers More Valid Symbols Note Note that this message does not necessarily indicate a problem Its purpose is to inform you that you might have the opportunity to get a more stable demodulation and or better measurement results by improving your setup Synchronization in the VSA application is performed in two stages coarse synchroni zation that precedes the reference signal generation and fine synchronization based on the reference signal coarse synchronization stage can work data aided i e based a known pat tern or non data aided i e based on the unknown data symbols The default is a non data aided coarse synchronization In the case that a pattern is part of signal the user can switch to data aided synchronization The fine synchronization stage always works data aided Sync Prefers More Valid Symbols indicates that one of the synchronization stages has too few symbols to ensure that the synchronization is robust The message is given if e Coarse Synchronization Non Data Aided User Pattern for Sync Off Estimation range shorter than 40 symbols see chapter 4 5 1 2 Estimation on page 101 e Fine Synchronization Estimation range shorter than 10 symbols User Manual 1176 8516 02 06 253 R amp S FPS K70 Optimizing and Troubleshooting the Measurement E see
348. ess data such as the Analyzer or optional applications RST IMMediate 11 5 5 Configuring VSA Example TRIG SOUR EXT Selects the external trigger input as source of the trigger signal Manual operation See Trigger Source on page 159 See Free Run on page 159 See External Trigger 1 2 on page 159 See IF Power on page 159 See Power on page 160 Configuring Sweeps The sweep commands define how often data from the input signal is acquired and then evaluated Manual configuration of the sweeps is described in chapter 5 6 3 Sweep Settings on page 161 SENSe DDEMod SEARGh MBURSEGALOG 552 307 SENSe SWEep COUNIt VALue cessisse nnne rnnt ennt nennen nnns 307 SENSe SWEep CODNEGCBIRGDLE ete 308 SENSe DDEMod SEARch MBURSt CALC lt SelResRangeNr gt Sets the result range to be displayed after a single sweep e g a burst number Setting parameters lt SelResRangeNr gt numeric value Range 1 to 1000000 RST 1 Default unit NONE Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Select Result Rng on page 163 SENSe SWEep COUNt VALue lt SweepCount gt This command sets the statistics count For more informati
349. estore Original Display on page 205 See Deactivating Zoom Selection mode on page 205 Using the Multiple Zoom DISPlay WINDow n ZOOM MULTiple zoom AREA eese 356 0 lt gt 2400 lt 2 gt 5 357 DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt AREA lt 1 gt lt 1 gt lt 2 gt lt 2 gt This command defines the zoom area for a multiple zoom To define a zoom area you first have to turn the zoom on RACER UTER RU WU IA _______________________ User Manual 1176 8516 02 06 356 R amp S9FPS K70 11 8 Remote Commands for VSA 1 Frequency Sweep 1 origin of coordinate system x1 0 y1 0 2 end point of system x2 100 2 100 3 zoom area e g x1 60 y1 30 x2 80 2 75 Suffix zoom 1 4 Selects the zoom window Parameters lt 1 gt lt 1 gt Diagram coordinates in 96 of the complete diagram that define lt 2 gt lt 2 gt the zoom area The lower left corner is the origin of coordinate system The upper right corner is the end point of the system Range 0 to 100 Default unit PCT Manual operation See Multiple Zoom on 205 DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt STATe State This command turns the mutliple zoom on and off Suffix zoom 1 4 Selects the zoom window If you turn off one
350. esult range of the capture buf fer is exported For the Magnitude Absolute Overview result display the trace contains a maximum of 25 000 points Note Secure user mode In secure user mode settings that are to be stored on the instrument are stored to vol atile memory which is restricted to 256 MB Thus a Memory full error may occur although the hard disk indicates that storage space is still available To store data permanently select an external storage location such as a USB memory device For details see Protecting Data Using the Secure User Mode in the Data ment section of the R amp S FPS User Manual Remote command MMEMory STORe lt n gt TRACe on page 373 Export Export Opens file selection dialog box to select an export file to which the IQ data will be stored This function is only available in single sweep mode and only in applications that process data such as the Analyzer or optional applications Note Secure user mode In secure user mode settings that are to be stored on the instrument are stored to vol atile memory which is restricted to 256 MB Thus a Memory full error may occur although the hard disk indicates that storage space is still available To store data permanently select an external storage location such as a USB memory device How to Export and Import Data For details see Protecting Data Using the Secure User Mode in the Data Manage
351. et enn 368 CAL Culate n STA istics MODE iie atu Loretta een eo te eati 368 DISPlay WINDow n ITEM LINE VALue eene 368 DISPlay WINDowsn PRATe AU TO nonii iirinn niyada tanii 369 bpISPlayDWINDowens PRATe ton cer noeh ntt narret tenente 370 DISPlay WINDow ens TRAGe SYMBOL 370 DISPlay WINDow n TRACe t Y SCALe MODE eese 370 CALCulate lt n gt DDEM SPECtrum STATe lt AddEvaluation gt This command switches the result type transformation to spectrum mode Spectral evaluation is available for the following result types e MAGNitude e PHASe UPHase e FREQuency Real Imag RIMAG The result types are defined using the CALC FORM command see CALCulate lt n gt FORMat on page 366 Setting parameters lt AddEvaluation gt ON OFF 1 0 RST 0 Example CALC FEED XTIM DDEM MEAS Selects the meas signal CALC FORM PHAS Selects the phase measurement CALC 5 ON Selects the spectral display of the phase Manual operation See Result Type Transformation on page 202 CALCulate lt n gt FEED Feed Selects the signal source and for the equalizer also the result type for evaluation Note that this command is maintained for compatibility reasons only Use the LAYout commands for new remote
352. eters lt MinGapLength gt numeric value Range 1 to 15000 RST 1 Default unit SYM Manual operation See Min Gap Length on page 166 SENSe DDEMod SEARch BURSt MODE lt MeasOnlyOnBurst gt This command sets the vector analyzer so that a measurement is performed only if a burst is found The command is available only if the burst search is activated see SENSe DDEMod SEARch BURSt STATe on page 310 11 5 6 2 Configuring VSA Setting parameters lt MeasOnlyOnBurst gt MEAS BURS MEAS Measurement is always performed BURS Measurement is performed only if a burst is found RST MEAS Manual operation See Measuring only if burst was found on 165 SENSe DDEMod SEARch BURSt STATe lt SearchState gt This command switches the search for a signal burst on or off Setting parameters lt SearchState gt ON OFF 1 0 RST 0 SENSe DDEMod SEARch BURSt TOLerance lt SearchTolerance gt This command controls burst search tolerance Setting parameters lt SearchTolerance gt numeric value Range 0 to 100000 RST 4 Default unit SYM Manual operation See Search Tolerance on page 166 Pattern Searches The pattern search commands define when a pattern is detected in the analyzed sig nal 5 2 2 100000 0000 310 SENS amp TDDEMed SEARGICS YNGOAU T 2 ciun
353. etween 1 and 6 traces may be displayed The Trace settings are displayed when you do one of the following e Select the Analysis button from the Overview then select the vertical Traces tab e Select the TRACE key Trace data can also be exported to an ASCII file for further analysis For details see chapter 6 2 Trace Export Settings on page 193 R amp S FPS KTO CE dl Analysis Mode Evaluation Clear Write View Blank Quick Config Set Trace Mode Set Trace Mode 275741 l Const I Q Meas amp Ref Trace 1 Trace 2 Trace 3 Trace 4 5 Trace 6 191 I 191 IU iuo MM 192 Predefined Trace Settings Quick 0 222 2 2 020 121444 0 nente 192 Trace 1 Trace 2 Trace 3 Ttace 4 Softkeys sees aia 192 Trace 1 2 Trace 3 Trace 4 5 Trace 6 Selects the corresponding trace for configuration The currently selected trace is high lighted orange Remote command DISPlay WINDowcn TRACe t STATe on page 340 Selected via numeric suffix of TRACe t commands Trace Mode Defines the update mode for subsequent traces The available trace modes depend on the selected result display Not all evaluations support all trace modes For the Magnitude Overview Absolute result display only the trace modes Cl
354. ew are available See also chapter 6 1 Trace Settings on page 190 Remote commands LAY ADD 1 BEL CBUF to define the required source type see LAYout ADD WINDow on page 359 CALC FORM MOV to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 1 Capture Buffer Results on page 375 E User Manual 1176 8516 02 06 41 R amp S9FPS K70 Measurements and Result Displays 3 2 23 3 2 24 Magnitude Relative Magnitude of the source signal the signal amplitude is scaled to the ideal reference signal Available for source types e Meas amp Ref Signal 2 MagRel Meas amp Ref 1M Clrw 49 sym Fig 3 14 Result display Magnitude Relative Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM MAGN to define the result type see CALCulate lt n gt FORMat on page 366 DISP TRAC Y MODE REL to define relative values see DISPlay WINDow lt n gt TRACe lt t gt Y SCALe MODE on page 370 TRAC DATA TRACE1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 Magnitude Error Displays the magnitude error of the measurement signal with respect to the reference signal as a function of sym
355. existing window By default the name of a window is the same as its index To determine the name and index of all active windows in the active measurement channel use the LAYout CATalog WINDow 2 query lt WindowType gt Type of result display you want to use in the existing window See LAYout ADD WINDow 2 on page 359 for a list of availa ble window types Example LAY REPL WIND 1 MTAB Replaces the result display in window 1 with a marker table LAYout SPLitter lt Index1 gt lt Index2 gt lt Position gt This command changes the position of a splitter and thus controls the size of the win dows on each side of the splitter R amp S FPS K70 Remote Commands for VSA Compared to the DISPlay WINDow lt n gt SIZE page 358 command the LAYout SPLitter changes the size of all windows to either side of the splitter per manently it does not just maximize a single window temporarily Note that windows must have a certain minimum size If the position you define con flicts with the minimum size of any of the affected windows the command will not work but does not return an error y 100 x 100 y 100 1 01 GHz 102 12 dim 0 y 0 x 100 Fig 11 1 SmartGrid coordinates for remote control of the splitters Parameters lt Index1 gt The index of one window the splitter controls lt Index2 gt The index of a window on the other side of the splitter lt Position gt New vertical or horizontal p
356. ey and select the VSA application 2 Select the Overview softkey to display the Overview for VSA 3 Select the Signal Description button and configure the expected signal character istics If the input data is largely known in advance define files with the known data to compare the measured data to see chapter 8 2 3 How to Manage Known Data Files on page 218 This can improve demodulation significantly 4 Select the Input Frontend button to define the input signal s center frequency amplitude and other basic settings 5 Select the Signal Capture button and define how much and which data to cap ture In MSRA mode define the application data instead see chapter 4 10 VSA in MSRA Operating Mode on page 124 e Capture length the duration or number of symbols to be captured e Sample rate how many points are to be captured for each symbol 6 Optionally select the Trigger tab and define a trigger for data acquisition for example an external trigger to start capturing data only when a useful signal is transmitted In MSRA mode define a Capture Offset instead see chapter 4 10 VSA in MSRA Operating Mode on page 124 7 For bursted signals select the Burst Pattern button and define the criteria to detect the individual bursts within the input signal see chapter 8 2 2 How to Per form Pattern Searches on page 214 How to Perform Customized Measurements 8 Select the Cut Result R
357. f enabled a header with scaling information etc is included in the file Remote command FORMat DEXPort HEADer on page 373 m A A M YOOC U User Manual 1176 851 6 02 06 193 Markers Decimal Separator Defines the decimal separator for floating point numerals for the data export files Eval uation programs require different separators in different languages Remote command FORMat DEXPort DSEParator on page 373 Trace ASCII Export Opens file selection dialog box and saves the traces of the captured data in ASCII format to the specified file and directory Either the traces for the selected window only see Specifics for on page 133 are exported or the traces of all windows are exported one after the other For details on the file format see chapter A 4 ASCII File Export Format for VSA Data on page 421 Remote command MMEMory STORe lt n gt TRACe on 373 6 3 Markers Markers help you analyze your measurement results by determining particular values in the diagram Thus you can extract numeric values from a graphical display e Individual Marker Sells cnt t creer t bcr aenea 194 Marker Search Setllhigs t rt a de e n 196 e Marker Positioning Functions essssesessssseeeeeneneenen nennen 198 6 3 1 Individual Marker Settings In VSA evaluations up to 5 markers can be activated in each
358. filters 431 rediit aes 425 Measurement filters 433 Paramelers acess e del eet t ete 425 Result Summary parameters 428 Result Summary parameters FSK 429 Standard specific filters 432 ijuod S 430 Trace averagihg erret entes 431 Transmit filters eiie E edt 432 Free Run Ii ES 159 Frequency Absolute result type eene 29 itr 146 Configuration remote 291 Formula Offset iate Relative result type Frequency error Absolute result type eene 32 425 Relative result type 33 RMS peak formulae 429 Frequency response Channel result type EDGE filters Low ISl filters Magnitude result type Phase result 2 nee tees Frequency Response Group Delay Channel result type 22 Result type niet t Here Pene 34 Frequency shift keying FSK Symbol mappihg 77 Frontend Config latiOti seriais iere etti ena 142 Configuration remote
359. fore using SENSe DDEMod SEARch SYNC NAME on page 314 Setting parameters Comment string Configuring VSA Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Edit on page 170 See New on page 170 See Comment on page 173 SENSe DDEMod SEARch SYNC COPY Pattern This command copies a pattern file The pattern to be copied must have been selected before using SENSe DDEMod SEARch SYNC NAME on page 314 Tip In manual operation a pattern can be copied in the editor by storing it under a new name Setting parameters Pattern string Example DDEM SEAR SYNC NAME GSM TSCO Selects the pattern DDEM SEAR SYNC COPY GSM PATT Copies GSM TSCO to GSM PATT Usage Setting only Manual operation See Save As on page 170 SENSe DDEMod SEARch SYNC DELete This command deletes a sync sequence The sync sequence to be deleted must have been selected before using SENSe DDEMod SEARch SYNC NAME on page 314 Usage Event Manual operation See Delete on page 171 SENSe DDEMod SEARch SYNC DATA lt Data gt This command defines the sync sequence of a sync pattern The pattern must have been selected before using SENSe DDEMod SEARch SYNC NAME on page 314 Important The value range of a symbol depends on the degree of modulation e g for an 8PSK
360. ge 296 You can query the x value that relates to the first value of the y axis using DISPlay WINDow lt n gt TRACe lt t gt X SCALe STARt on page 372 The eye diagram result displays are the same as the real imag result display the results for eye diagrams are merely superimposed in the display 11 9 2 3 Polar Diagrams For polar diagrams the command returns a pair of values for each trace point The first value is the real part the second value the imaginary part The number of returned value pairs depends on the result type e Vector I Q evaluation range length display points per symbol Constellation evaluation range length Constellation Frequency and Vector Frequency one value for each trace point on the y axis 11 9 2 4 Symbols For the symbol table result diagrams the command returns one value for each num ber in the table The command always returns the values in the decimal format The number of returned values depends on the modulation scheme you have selected 11 9 2 5 Result Summary For the Result Summary the command returns all values listed in the result table from top to bottom i e lt EVM_RMS gt lt EVM_Peak gt lt MER_RMS gt lt MER_Peak gt lt Phase Error RMS gt lt Phase Error Peak gt lt MagError_RMS gt lt MagError_Peak gt lt Carrier Frequency 11 9 2 6 11 9 3 Retrieving Results Error Rho I Q gt lt 1 Imbalance gt lt Gain Imbalance
361. ge 412 For detailed instructions see chapter 8 1 How to Perform VSA According to Digital Standards on page 210 Digital standard settings are available via the Digital Standards button in the Over view or the Digital Standards softkey in the MEAS menu ENG Welll Ste re ode oce urere toe 130 L Selecting the Storage Location Drive Path 130 M MONT 130 NE 130 ere Tt RARRRRRRRRRRRRRRRRRRRRRRRRMMMMMMMMMMMMAEKHFPPSHE ENMAEMMME 131 L Load 131 L Save Standard ertt otn Dra lc aac need 131 L Delete Staridard ttti tk tna ti khai 131 L Restore Standard Files eese 22 tentat ttt tnnt don 131 Digital Standards Opens file selection dialog to manage predefined measurement settings for conven tional mobile radio standards Selecting the Storage Location Drive Path Files Digital Standards Select the storage location of the settings file on the instrument or an external drive The Drive indicates the internal C or any connected external drives e g a USB storage device The Path contains the drive and the complete file path to the currently selected folder The Files list contains all subfolders and files of the currently selected path The default storage location for the standards files is C R_S Instr us
362. ge space is still available To store data permanently select an external storage location such as a USB memory device For details see Protecting Data Using the Secure User Mode in the Data Manage ment section of the R amp S FPS User Manual Parameters Trace Number of the trace to be stored lt FileName gt String containing the path and name of the target file Example MMEM STOR1 TRAC 3 C TEST ASC Stores trace from window 1 in the file TEST ASC Usage SCPI confirmed Manual operation See Trace ASCII Export on page 194 See Export Trace to ASCII File on page 207 SENSe DDEMod SEARch MBURSt STARt This command queries the start of the current result range within the capture buffer Return values lt StartValue gt Symbol or time at which x axis starts Example INIT CONT OFF switch to single sweep mode INIT WAI perform single sweep SENS DDEM SEAR MBUR CALC 1 switch to first result range SENS DDEM SEAR MBUR START query start of current first result range in the capture buffer SENS DDEM SEAR MBUR CALC 2 switch to second result range SENS DDEM SEAR MBUR START query start of current result range in the capture buffer Usage Query only TRACe lt n gt DATA Trace This command queries the trace data Which data is returned depends on the result display in the window specified by the suffix n Retrieving Results Fo
363. gnal Burst Signal Burst Min Length 148 sym 546 462 us Max Length 148 sym 546 462 us Run In 8 sym 11 077 us Run Out 8 sym 11 077 us W Pattern Oo l _____ Start 13 sym Name 1 M Mag CapBuf w Offset 58 sym 214 154 us Description K Burst Length Run In GES Offset Start 0 sym Stup 1900 Syiti Fig 10 9 The red circle shows the place where you can specify a pattern Solution Select an existing pattern or create a new pattern that you expect to be within the signal For more information see e Pattern Settings on page 140 chapter 8 2 2 How to Perform Pattern Searches on page 214 Message Pattern Not Entirely Within Result Range A pattern can only be found if it is entirely within the result range Therefore this error message always occurs with a Pattern Not Found error Solution Choose the pattern as reference of your result range alignment Then the pattern will be forcefully part of your result range and the pattern search can succeed For more information see chapter 5 8 Result Range Configuration on page 173 e chapter 8 2 4 How to Define the Result Range on page 220 Message Short Pattern Pattern Search Might Fail The R amp S FPS performs the pattern search in two stages e Stage 1 involves the generation of an pattern waveform by modulating the pat tern symbol se
364. gnal and calculation of the signal parameters becomes quicker For details on burst and patterns see chapter 4 4 Overview of the Demodulation Proc ess on page 88 Burst Search The Burst Search settings define when a burst is detected in the evaluated signal A live preview of the capture buffer with the current settings is displayed in the preview area at the bottom of the dialog box The blue lines below the trace indicate the detec ted bursts The preview area is not editable directly The Burst Search settings are displayed when you do one of the following Select the Burst Pattern button from the Overview e Select the Burst Pattern Search softkey from the main VSA menu R amp S FPS K70 Configuration Burst Search Pattern Search Auto according to Signal Structure Advanced Meas only if Burst found Auto Configuration Search Tolerance 14 769 Minimum Gap Length 3 692 us Information Expected Burst Length 148 4 sym Burst Found Preview Preview Mag CapBuf Start 0 sym Stop 1500 sym E I 165 MT 165 deci E MI I IM 166 L Search prre ce dd ka ed Dn Re n ek cr eda 166 L 166 Enabling Burst Searches Enables or disables burst searches If Auto is selected burst search is enabled only if the signal structure defines a bursted signal in the Signal Structure tab of the Modu lation amp Signal Description dialog box see on page 139
365. gnals are referred to as signals signals are useful because the specific RF or IF frequencies are not needed The complete modulation information and even distortion that originates from the RF IF or baseband domains can be ana lyzed in the baseband Importing and exporting signals is useful for various applications e Generating and saving signals in an RF or baseband signal generator or in external software tools to analyze them with the R amp S FPS later e Capturing and saving I Q signals with an RF or baseband signal analyzer to ana lyze them with the R amp S FPS or an external software tool later As opposed to storing trace data which may be averaged or restricted to peak values data is stored as it was captured without further processing data is stored as complex values in 32 bit floating point format Multi channel data is not supported The data is stored in a format with the file extension For a detailed description see the R amp S FPS Analyzer and Input User Manual Export only in MSRA mode In MSRA mode data only be exported to other applications data cannot be imported to the MSRA Master or any MSRA applications e lmporU Export FUIQUOLIS 206 e Howto Export and lmport VQ 2 rtt i tet hee d t tren tns 208 Import Export Functions The following import and export functions are available via softkeys
366. gt lt Quadratue Error Amplitude Droop gt lt Power gt lt Symbol Rate Error Note that the Symbol Rate Error was appended at the end to provide compatibility to previous versions and instruments For each result type both the current and statistical values are provided The order of the results is as follows result1 current result mean result1 peak lt result1_stddev gt result1 95 gt result2 current result2 gt Empty cells in the table return nothing The number of returned values depends on the modulation scheme you have selected PSK MSK and QAM modulation returns 85 values FSK modulation returns 55 values The unit of each value depends on the par ticular result For more details on the Result Summary see chapter 3 2 29 Result Summary on page 47 Equalizer For Equalizer diagrams the command returns the y axis values of the equalizer trace The number of returned values depends on the result type Forimpulse response diagrams filter length sample rate 1 For frequency response channel and group delay diagrams 4096 values You can query the x value that relates to the first value of the y axis using DISPlay WINDow lt n gt TRACe lt t gt X SCALe STARt on page 372 Retrieving Parameter Values For each parameter the VSA application calculates and shows various statistical val ues Current value Mean value Calculated as the
367. gt next to the keyword If you don t quote a suffix for keywords that support one a 1 is assumed Example DISPlay WINDow lt 1 4 gt ZOOM STATe enables the zoom in a particular mea surement window selected by the suffix at WINDow DISPlay WINDow4 ZOOM STATe ON refers to window 4 11 1 4 Optional Keywords Some keywords are optional and are only part of the syntax because of SCPI compli ance You can include them in the header or not Note that if an optional keyword has a numeric suffix and you need to use the suffix you have to include the optional keyword Otherwise the suffix of the missing keyword is assumed to be the value 1 Optional keywords are emphasized with square brackets Example Without a numeric suffix in the optional keyword SENSe FREQuency CENTer is the same as FREQuency CENTer With a numeric suffix in the optional keyword DISPlay WINDow lt 1 4 gt ZOOM STATe DISPlay ZOOM STATe ON enables the zoom in window 1 no suffix DISPlay WINDow4 ZOOM STATe ON enables the zoom in window 4 Introduction 11 1 5 Alternative Keywords A vertical stroke indicates alternatives for a specific keyword You can use both key words to the same effect Example SENSe BANDwidth BWIDth RESolution In the short form without optional keywords BAND 1MHZ would have the same effect as BWID 1MHZ 11 1 6 SCPI Parameters Many commands feature one or more parameters If
368. h SYNC TEXT ttt ttt ttt ttt ttt s sod 315 5 51 9 286 5 286 5 5 5 282 5 5 274 SENSe DDEMod STANdard DELete 274 SENSe DDEMod STANdard PREset VALue ettet ttt ntis 275 5 5 0 9 9 275 5 5 5 2 2 11 ttt ttt 287 5 5 8 287 5 283 SENS amp DDEMOodQ TFILter NAME eonun nennen eerta RES eH saa CERES E SE TERN E ERR es 283 SENSe DDEMod TFILter USER SENSe DDEMod TFlLter STATe SENSe DD EMO ESEE EEE SENS amp DBEMOG USER NAME eer regt conta e PA PY EORR o Lew EVERY
369. hapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Edit on page 170 See New on page 170 See Description on page 172 11 5 7 Defining the Result Range The result range determines which part of the capture buffer burst or pattern is dis played Manual configuration of the result range is described in chapter 5 8 Result Range Configuration on page 173 Useful commands for result ranges described elsewhere SENSe DDEMod SEARCh MBURst STARt on page 374 DISPlay WINDow lt n gt TRACe lt t gt X SCALe STOP on page 372 Configuring VSA Remote commands exclusive to defining result ranges CALOCulate n TRACe t ADJust ALIGnment DEFault ccce eene 316 gt lt gt 2 316 gt lt gt 317 lt gt lt gt 5 2 0000 0 317 SENSeHDDEMOGTIME 2 crea ob eee eade taste dude ceu er Le sed ena n 317 CALCulate lt n gt TRACe lt t gt ADJust ALIGnment DEFault Alignment This command defines where the reference point is to appear in the result range Suffix lt gt 1 6 Setting parameters
370. have a constant phase offset of 0 11 2 or 317 2 This offset can only be detected and elimi nated if a pattern was successfully detected at symbol level see also chapter 4 4 4 Pattern Symbol Check on page 96 If modulation types are used where the information is represented by the phase transi tion e g differential PSK or MSK the absolute phase position is not an issue Thus the ambiguity of the starting phase does not have an influence on the symbol deci sions If the measurement signal contains a known pattern it is also possible to use a data aided DA estimator at this stage This means that the estimator operates on a known data sequence i e the pattern If the signal contains a pattern it is possible to choose between the above described non data aided estimator and the data aided estimator with the setting Coarse Synchronization Pattern If the data aided estimator is employed the phase ambiguitiy can be resolved at this stage Overview of the Demodulation Process Demodulation amp Symbol Decision Setings IQ Samples From Result Range Extract Result Range IQ Meas with corrected timing IQ Meas with corrected timing phase frequency offset scaling Symbol Decision IQ Meas corrected IQ Symbols Passed on to Pattern Symbol Check Fig 4 45 Demodulation and Symbol Decision algorithm Overview of the Demodulation Process 4 4 A Patt
371. he Modulation tab of the Signal Description dialog box select Transmit Fil ter Type User 3 Select Load User Filter 4 Load your vaf file from the USB stick How to Perform Customized Measurements 8 2 2 How to Perform Pattern Searches To configure a pattern search 1 In the Overview select Signal Description 2 Select the Signal Structure tab 3 Select the Burst Signal signal type 4 Enable the Pattern option 5 From the Name selection list select a pattern that is assigned to the currently defined standard 6 Ifthe pattern you require is not available continue with To add a predefined pat tern to a standard on page 214 or chapter 8 2 2 2 How to Define a New Pat tern on page 215 7 Optionally select the Offset option and enter the number of symbols in the signal to be ignored during the pattern search 8 Close the Signal Description dialog box 9 In the Overview dialog box select Burst Pattern and switch to the Pattern Search tab 10 Select On to enable the search To enable a search only if a pattern is part of the signal description enable the Auto option The results of the pattern search with the selected pattern on the current measure ment data is displayed in the Preview area of the dialog box Whether a pattern was detected or not is indicated in the Information area 11 If necessary adapt the correlation threshold If bursts
372. he Signal Structure tab Select Pattern Config to display the Advanced Pattern Settings dialog box Select the pattern from the list of All Patterns Press Edit Pattern o Change the settings as required as described in chapter 8 2 2 2 How to Define New Pattern on page 215 To delete a predefined pattern 1 In the Overview select Signal Description and switch to the Signal Structure tab 2 Select Pattern Config to display the Advanced Pattern Settings dialog box 3 Select the pattern from the list of All Patterns 4 Press Delete Pattern The pattern is removed from the lists of available and assigned patterns and can no longer be assigned to any standard Any existing assignments to other stand ards are removed as well To restore predefined patterns Default patterns provided by Rohde amp Schwarz can be restored 1 Press the MEAS key 2 Select Restore Factory Settings softkey 3 Select the Restore Pattern Files softkey The patterns as defined by Rohde amp Schwarz at the time of delivery are restored How to Perform Customized Measurements 8 2 3 8 2 3 1 Restoring user defined patterns User defined patterns can only be restored if you have a copy of the pattern file cre ated during creation In this case copy the file named Patternname xml back to the installation directory of the VSA application under vsa standards After a preset or af
373. he sample rate leads to a sufficient data bandwidth The whole spectrum of the input signal is captured but most adjacent channels and interferers are effectively suppressed Only for very wide signals FSK no TX filter used it can be necessary to try higher values for the sample rate see chapter 4 2 Sample Rate Symbol Rate and Bandwidth on page 63 increasing the bandwidth The data delivered to the DSP section has no considerable amplitude or phase distor tion and a suitable bandwidth the usable bandwidth achieved for the current settings see Usable 1 0 Bandwidth o The Signal Capture dialog box Data Acquisition tab shows the sample rate and on page 156 After the optional measurement filter The measurement signal and the reference signal can be filtered by various mea surement filters which have different bandwidths The filters described above are the ones that directly affect the bandwidth of the cap tured data and the final measurement signal and reference signal Note however that several other filters are also involved in the DSP section but are not mentioned above e Receive filter to prevent ISI intersymbol interference e filters necessary for various estimators others 4 1 4 I Q Bandwidth The bandwidth of the data used as input for the vector signal analysis is filtered as described in chapter 4 1 Filters and Bandwidths During Signal Processing on page
374. he Known Data file Setting parameters lt FileName gt string Manual operation See Load Data File on page 142 SENSe DDEMod NORMalize ADRoop lt CompAmptDroop gt This command switches the compensation of the amplitude droop on or off Setting parameters lt CompAmptDroop gt OFF 110 RST 1 Manual operation See Compensate for PSK ASK QAM on page 178 SENSe DDEMod NORMalize CFDRift lt CarrFreqDrift gt This command defines whether the carrier frequency drift is compensated for FSK modulation Setting parameters lt CarrFreqDrift gt ON OFF 1 0 RST 0 Manual operation See Compensate for FSK on page 179 SENSe DDEMod NORMalize CHANnel lt TransmitChannel gt This command switches the channel compensation on or off With equalizer only Setting parameters lt TransmitChannel gt OFF 1 0 RST 1 Manual operation See Compensate for PSK MSK ASK QAM on page 178 SENSe DDEMod NORMalize FDERror lt RefDevComp gt This command defines whether the deviation error is compensated for when calculat ing the frequency error for FSK modulation Configuring VSA Setting parameters lt RefDevComp gt ON OFF 1 0 ON Scales the reference signal to the actual deviation of the mea surement signal OFF Uses the entered nominal deviation for the reference signal RST 1 Manual operation See Compensate for FSK on page 179 SENSe DDEMod NO
375. he estimation points per symbol or display points per symbol see chapter 4 7 Display Points vs Estimation Points per Symbol on page 121 The resulting sample rate depending on the Sym bol Rate is indicated behind the parameter The number of samples to capture per symbol was referred to as the Capture Over sampling value in previous R amp S signal and spectrum analyzers The resulting sample rate also referred to as the user or output sample rate is the rate at which the data is demodulated and analyzed The sample rate also affects the demodulation measurement bandwidth If the bandwidth is too narrow the signal is not displayed completely If the bandwidth is too wide interference from outside the actual signal to be measured can distort the result Thus for signals with a large fre quency spectrum e g FSK modulated signals a higher sample rate may be neces For further details see chapter 4 1 Filters and Bandwidths During Signal Process ing on page 56 For an indication of the required sample rate view the Real Imag I Q display of the capture buffer with a Spectrum transformation If the complete signal is displayed within the usable bandwidth the selected value is suitable 5 1 Clrw usable I Q Bandwidth 7 68 MHz 7 68 MHz Fig 4 5 Determining the I Q bandwidth Real Imag I Q display of the capture buffer with a
376. he vector analyzer so that the measurement is performed only if the measurement was synchronous to the selected sync pattern The command is available only if the pattern search is activated see SENSe DDEMod SEARch SYNC STATe on 312 Setting parameters lt MeasOnlyOnPatt gt MEAS SYNC MEAS The measurement is performed independently of successful synchronization SYNC The measured values are displayed and considered in the error evaluation only if the set sync pattern was found Bursts with a wrong sync pattern sync not found are ignored If an invalid or no sync pattern is found the measurement waits and resumes running only when a valid sync pattern is found RST 0 Manual operation See Meas only if Pattern Symbols Correct on page 168 11 5 6 3 Configuring VSA SENSe DDEMod SEARch SYNC SELect Select This command selects a predefined sync pattern file Setting parameters Select string Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Selected Pattern for Search on page 168 See Standard Patterns selecting an assigned pattern on page 169 SENSe DDEMod SEARch SYNC STATe lt PatternSearch gt This command switches the search for a sync sequence on or off Setting parameters lt PatternSearch gt ON OFF 1 0 RST 0 Manual operation
377. highlighted The running measurement can be aborted by selecting the highlighted softkey or key again The results are not deleted until a new measurement is started Signal Capture Note Sequencer If the Sequencer is active the Continuous Sweep softkey only controls the sweep mode for the currently selected channel however the sweep mode only has an effect the next time the Sequencer activates that channel and only for a channel defined sequence In this case a channel in continuous sweep mode is swept repeatedly Furthermore the RUN CONT key controls the Sequencer not individual sweeps RUN CONT starts the Sequencer in continuous mode For details on the Sequencer see the R amp S FPS User Manual Remote command INITiate lt n gt CONTinuous on page 333 Single Sweep RUN SINGLE After triggering starts the number of evaluations set in Statistics Count The mea surement stops after the defined number of evaluations has been performed While the measurement is running the Single Sweep softkey and the RUN SINGLE key are highlighted The running measurement can be aborted by selecting the high lighted softkey or key again Remote command INITiate n IMMediate on page 334 Continue Single Sweep After triggering repeats the number of evaluations set in Statistics Count without deleting the trace of the last measurement While the measurement is running the Continue Single Sweep softkey and the RUN SINGLE key
378. his command changes the window type of an existing window specified by the suffix lt n gt in the active measurement channel The result of this command is identical to the LAYout REPLace WINDow com mand To add a new window use the LAYout WINDow lt n gt ADD command Parameters lt WindowType gt Type of measurement window you want to replace another one with See LAYout ADD WINDow on page 359 for a list of availa ble window types LAY out WINDow lt n gt TYPe Queries the window type of the window specified by the index lt n gt For a list of possi ble window types see LAYout ADD WINDow 2 on page 359 Example LAY WIND2 TYPE Response MACC Modulation accuracy Usage Query only 11 8 3 VSA Window Configuration For each window you can select a different evaluation method result type based on the data source selected in the Display Configuration Further window settings are available for some result types Manual configuration of VSA windows is described in chapter 6 5 1 Window Configu ration on page 202 Useful commands for configuring the window described elsewhere LAYout ADD WINDow 2 on page 359 Configuring the Result Display Remote commands exclusive to configuring VSA windows CALCulatesmsDDEM SPECtFUl STAT itat erbe 365 e ECT ll 365 lt FOR Malte EET 366 CALOCulate n STATistics CCDF STATe essere ner
379. ific status registers e STATus QUEStionable SYNC lt n gt Register esee 394 e STATus QUEStionable MODulation lt n gt 394 e STATus QUESTionable MODulation lt n gt EVM 394 e STATus QUESTionable MODulation lt n gt PHASe 395 e STATus QUESTionable MODulation lt n gt MAGnitude Register 395 e STATus QUESTionable MODulation lt n gt CFRequency 396 e STATus QUESTionable MODulation lt n gt IQRHO 396 e STATus QUESTionable MODulation lt n gt FSK 397 e Querying the Status rd nece ans 397 Status Reporting System 11 11 1 STATus QUEStionable SYNC n Register This register contains application specific information about synchronization errors or errors during burst detection for each window in each VSA channel It can be queried with commands STATus QUEStionable SYNC CONDition on page 399 and STATus QUEStionable SYNC EVENt on page 400 Table 11 4 Status error bits in STATus QUEStionable SYNC register for R amp S FPS K70 Bit Definition 0 Burst not found This bit is set if a burst could not be detected 1 Sync not found This bit is
380. igure at the same time depends on available memory Parameters lt ChannelType gt Channel type of the new channel For a list of available channel types see INSTrument LIST on page 271 lt ChannelName gt String containing the name of the channel The channel name is displayed as the tab label for the measurement channel Note If the specified name for a new channel already exists the default name extended by a sequential number is used for the new channel see INSTrument LIST on page 271 Example INST CRE SAN Spectrum 2 Adds an additional spectrum display named Spectrum 2 INSTrument CREate REPLace lt ChannelName1 gt lt ChannelType gt lt ChannelName2 gt This command replaces a measurement channel with another one Setting parameters lt ChannelName1 gt String containing the name of the measurement channel you want to replace lt ChannelType gt Channel type of the new channel For a list of available channel types see INSTrument LIST on page 271 Activating Vector Signal Analysis lt ChannelName2 gt String containing the name of the new channel Note If the specified name for a new channel already exists the default name extended by a sequential number is used for the new channel see INSTrument LIST on page 271 Example INST CRE REPL Spectrum2 IQ IQAnalyzer Replaces the channel named Spectrum2 by a new measure ment channel of type IQ Analyzer named IQAnalyzer
381. importing and exporting data see the R amp S FPS User Manual e Default Settings for Vector Signal Analysis essen 128 e Configuration According to Digital 129 e odd err tre dt bdo trt c tre e rd o tu me dte c pt 132 LEE Ie Beige M n 134 e Input Output and Frontend 8 142 Default Settings for Vector Signal Analysis P 154 e Burstand Pattern Configuratio ss tr ERREUR 164 e Result Range Configuration nre EE kn nara kn dita 173 LDetmod lator Songs ri aed e 175 e Measurement Filter Settings ciere LE EUER YE REPRE 185 Evaluation Range Conflgurallon treten t etre ide 187 e Adjusting Settings Automatically eese 188 5 1 Default Settings for Vector Signal Analysis When you switch the application of a measurement channel to the first time a set of parameters is passed on from the currently active application center frequency and frequency offset reference level and reference level offset attenuation signal source and digital I Q input settings input coupling After initial setup the parameters for th
382. in ing can start again using the command DDEM EQU MODE TRA see SENSe DDEMod EQUalizer MODE on page 321 Usage Event Manual operation See Reset Equalizer on page 180 SENSe DDEMod EQUalizer SAVE Name This command saves the current equalizer results to a file Setting parameters Name string File name Example DDEM EQU SAVE D MMyEqualizer Saves the current equalizer results to D MyEqualizer vae Manual operation See Store Load Current Equalizer on page 180 SENSe DDEMod EQUalizer STATe State This command activates or deactivates the equalizer For more information on the equalizer see chapter 4 4 5 The Equalizer on page 97 Setting parameters State ON OFF 1 0 RST OFF Example DDEM EQU OFF Manual operation See State on page 179 SENSe DDEMod FSYNc AUTO lt FineSyncAuto gt This command selects manual or automatic Fine Sync Setting parameters lt FineSyncAuto gt ON OFF 1 0 RST 1 Manual operation See Fine Synchronization on page 183 SENSe DDEMod FSYNc LEVel lt SERLevel gt This command sets the Fine Sync Level if fine sync works on Known Data Configuring VSA Setting parameters SERLevel numeric value Range 0 0 to 100 0 RST 10 0 Default unit PCT Manual operation See If SER lt on page 184 SENSe DDEMod FSYNc RESult The result of this query is O if the fine sync with kn
383. in the Save Recall menu which is displayed when you select the Save or Open icon in the tool bar Some functions for particular data types are also available via softkeys or dialog boxes in the corresponding menus e g trace data or marker peak lists For a description of the other functions in the Save Recall menu see the R amp S FPS User Manual uso M 207 TRE TENET 207 jos MM M ES 207 L Export Trace to ASCII File 207 i 207 Import Export Functions Import Provides functions to import data Import Import Opens file selection dialog box to select an import file that contains IQ data This function is only available in single sweep mode and only in applications that process data such as the Analyzer or optional applications Note that the data must have a specific format as described in the R amp S FPS I Q Analyzer Input User Manual Remote command MMEMory LOAD IQ STATe on page 390 Export Opens a submenu to configure data export Export Trace to ASCII File Export Opens file selection dialog box and saves the selected trace in ASCII format dat to the specified file and directory The results are output in the same order as they are displayed on the screen window by window trace by trace and table row by table row Note that only the trace data in the currently displayed r
384. ined by Statistics Count cannot be edited directly SGL The sweep is set to single sweep mode In addition the channel bar also displays information on instrument settings that affect the measurement results even though this is not immediately apparent from the display of the measured values e g transducer or trigger settings This information is dis played only when applicable for the current measurement For details see the R amp S FPS Getting Started manual Window title bar information For each diagram the header provides the following information 1 Const I Q Meas amp Ref 1M Clrw Fig 2 1 Window title bar information in VSA application 1 Window name 2 Result type 3 Data source type 4 Trace color 5 Displayed signal for Meas amp Ref data source M Meas or R Ref 6 Trace mode Diagram area The diagram area displays the results according to the selected result displays see chapter 3 Measurements and Result Displays on page 14 Diagram footer information The diagram footer beneath the diagram contains the start and stop symbols or time of the evaluation range Status bar information Global instrument settings the instrument status and any irregularities are indicated in the status bar beneath the diagram Furthermore the progress of the current operation is displayed in the status bar R amp S FPS K70 Measurements and Result Displays 3 Measurements and Result Displ
385. ing is relative to the current reference level for RF input e Scaling is relative to the full scale level for I Q input Real RealImag CaptureBuffer 4 Imag RealImag CaptureBuffer ei Clrw 8000 sym Fig 3 19 Result display Real Imag Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM RIMag to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 3 2 29 Result Summary The Modulation Accuracy results in a table For details on the parameters see chap ter 3 3 Common Parameters in VSA on page 54 Basis of evaluation The majority of the values that are displayed in the Result Summary are calculated over the Evaluation Range see chapter 5 11 Evaluation Range Configuration on page 187 They are evaluated according to the setting of the Display Points Sym parameter For example if Display Points Symbol is 1 only the symbol instants contribute to the result displayed in the result summary Table 3 2 Results calculated over the evaluation range PSK MSK QAM FSK EVM Frequency Error MER Magnitude Error Phase Error Power User Manual 1176 8516 02 06 47 Result Types in VSA PSK MSK QAM Magnitude Error FSK
386. ing option is selected in the demodulation settings In this case the imbalance does not affect the EVM Note that the imbalance is not estimated and cannot be compensated for in a BPSK signal Amplitude Droop The decrease of the signal power over time in the transmitter is referred to amplitude droop E Magnitude of Meas Signal relative T N 0 50 100 150 200 Time Symbols Fig 4 57 Effect of amplitude droop Signal Model Estimation and Modulation Errors Gain Distortion Table 4 17 Effect of nonlinear amplitude distortions Nonlinear distortions amplitude distortion transmit ter Amplitude distortion analyzer Gain Distortion Transmitter 0 02 03 04 05 06 07 06 Real Gain Distortion Analyzer 0 01 02 03 04 Rew 05 06 07 08 The effect of nonlinear amplitude distortions a 64QAM signal are illustrated in table 4 17 only the first quadrant is shown The transfer function is level dependent the highest effects occur at high input levels while low signal levels are hardly affected The signal is scaled in the analyzer so that the average square magnitude of the error vector is minimized The second column shows the signal after scaling Table 4 18 Amplitude transfer functions Amplitude transfer function transmitter Amplitude transfer function analyzer Mtglbute Tiatster function Tars meien 08 05 04 02
387. ing the reference signal and the measured signal and is only applied to the measured signal This is referred to as normal equalizer mode Note that the resulting equalizer function is not simply the inverted distortion function For more complex distortions the reference signal might not be determined correctly due to wrong symbol decisions Despite the resulting imperfect equalizer calculation the estimated equalizer is often good enough to improve the reference signal creation in the succeeding sweep Thus the new equalizer is improved successively This pro cessing mode of the equalizer is called tracking mode After only few sweeps the results are sufficiently accurate and the learning phase is completed Then the equal izer can be used without additional calculations as long as the input signal remains sta ble If an unstable input has led to an unusable equalizer filter reset the equalizer with the Reset button REF Filter IQ Input ISI Signal Filter IQ Reference Equalizer Compensate for Averaging Control MEAS Filter IQ Measure ment Signal Fig 4 49 An equalizer filter can be activated in the reference and measurement signal path The filter coefficients are determined in such a way that the error vector magnitude EVM is minimized User Manual 1176 8516 02 06 98 R amp S FPS K70 Measurement Basics The result range used for equalizer calculation might be quite short lea
388. ings er rrr rk Source Configuration Source Configuration Softkey 142 Input sample rate ISR cecinerunt c ed 64 Input sources erre esee ete ton 143 Input Frontend 142 instalation terrent 10 Intersymbol interference ISI 58 Filter ISI free system K Keys BW notused eee et et t toes ll c c MKR FUNCT not used Peak Se8EOlT dee qe merita e cc RUN SINGLE SPAN not used Known data Creating files Dependencies restrictions Pm 142 ei sre ti ee eben ences eine ick On eua 423 lice 218 Fine synchronization 183 184 Loading niacino e 142 Recording tool 219 Symbol decisions i rien neri ena top oe te 94 WOTKINO neci ect 218 L Limit lines Current mean peak values 200 Default toe tte e s dax 200 me oerte a mt ma eoa 200 Modulation aCCUracy iiss isnt E tee 199 Peak Search sonoris em e sae 197 Values Values checking noire 201 Limits CONGU ra
389. ion REFerence VALue 1th nnn rnnt CALOCulate n LIMit MACCuracy ResultType LimitType STATe seen CALCulate lt n gt LIMit MACCuracy lt ResultType gt lt LimitType gt RESUIt lt gt 11 5 lt gt 11 1 lt gt 11 5 388 CALCulate lt n gt LIMit MACCuracy CFERror MEAN STATe CALCulate lt n gt LIMit MACCuracy CFERror MEAN VALue CALCulate lt n gt LIMit MACCuracy CFERror MEAN RESUlt eese 388 lt gt 11 5 350 lt gt 11 351 lt gt 11 5 0 0 388 CALCulatesn LIMIEMAGGuracy DEEatull coreano coy eene rtr pner Fate ba n CALCulate lt n gt LIMit MACCuracy EVM PCURrent STATe nz lt gt 11 1 lt gt 11
390. ion See chapter 5 7 Burst and Pattern Configuration on page 164 Result Range Definition See chapter 5 8 Result Range Configuration on page 173 Demodulation Settings See chapter 5 9 Demodulation Settings on page 175 Configuration Overview 7 Measurement Filter Settings See chapter 5 10 Measurement Filter Settings on page 185 8 Evaluation Range Definition See chapter 5 11 Evaluation Range Configuration on page 187 9 Display Configuration The Display Config button is only available in the general overview not in the window specific overview see Specifics for on page 133 See chapter 6 5 Display and Window Configuration on page 201 10 Analysis See chapter 6 Analysis on page 190 To configure settings Select any button in the Overview to open the corresponding dialog box Select a setting in the channel bar at the top of the measurement channel tab to change a specific setting For step by step instructions on configuring measurements see chapter 8 How to Perform Vector Signal Analysis on page 210 Preset Channel Select the Preset Channel button in the lower lefthand corner of the Overview to restore all measurement settings in the current channel to their default values Note that the PRESET key restores the entire instrument to its default values and thus closes all measurement channels on the R amp S FPS except for the default Spectrum application channel See
391. ion accuracy measurement can be checked for violation of defined limits automatically see Modulation Accuracy on page 17 Limits and the limit check are configured in the Limits dialog box that is displayed when you press the ModAcc Limits Config softkey in the Lines menu Limit Checking On off Set to Default Current Mean Peak Limit Value Check Magnitude Error Peak Carrier Frequency Error Rho 0 999 1 Offset 40 0 Note Limits for Current and Peak are always equal For details on working with limits see chapter 8 3 2 How to Check Limits for Modula tion Accuracy on page 225 Checking Modulation Accuracy rre EP rct eere ciim EX Modulation Accuracy Limit Lines Checking Modulation Accuracy Limits Activates or deactivates evaluation of modulation accuracy limits in the result sum mary Remote command CALCulate n LIMit MACCuracy STATe on page 349 Set to Default Restores the default limits and deactivates all checks Remote command CALCulate n LIMit MACCuracy DEFault on page 349 Current Mean Peak Defines and activates the limits for the currently measured value the mean and the peak value on separate tabs Note that the limits for the current and peak values are always the same Limit Value Current Mean Peak Define the limit with which the currently measured mean or peak value is to be com pared A different limit value can be d
392. is command is not available for result displays based on the capture buffer in this case the displayed points per symbol are defined by the sample rate SENSe DDEMod PRATe command Setting parameters lt DisplayPPS gt 1 2 4 8 16 or 32 1 only the symbol time instants are displayed 2 4 8 16 32 more points are displayed than symbols RST 4 Manual operation See Display Points Sym on page 203 DISPlay WINDow lt n gt TRACe SYMBol This command enables the display of the decision instants time when the signals occurred as dots on the trace Manual operation See Highlight Symbols on page 203 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe MODE Mode This command selects the type of scaling of the y axis for all traces t is irrelevant When the display update during remote control is off this command has no immediate effect Parameters Mode ABSolute absolute scaling of the y axis RELative relative scaling of the y axis RST ABSolute Example DISP TRAC Y MODE REL 11 9 Retrieving Results The following commands are required to retrieve the calculated VSA parameters Retrieving Results 11 9 1 results that are not based on the capture buffer data are calculated for a single result range only see chapter 4 6 1 Result Range on page 117 To retrieve the results for several result ranges use the SENSe DDEMod SEARch MBURst CALC on page 307 co
393. is of equalizer group delay measurements Setting parameters lt Unit gt S SYM 5 SYM Manual operation See Y Axis Unit page 154 Configuring VSA DISPlay WINDow lt n gt TRACe lt t gt X SCALe PDIVision lt PDiv gt This command defines the scaling of the x axis for statistical result displays For all other result displays this command is only available as a query Setting parameters lt PDiv gt numeric value Defines the range per division total range 10 lt PDiv gt Manual operation See Range per Division on page 153 DISPlay WINDow lt n gt TRACe lt t gt X SCALe RPOSition lt RPos gt This command defines the position of the reference value for the X axis Setting the position of the reference value is possible only for statistical result displays All other result displays support the query only Setting parameters lt RPos gt numeric value lt numeric_value gt Example DISP TRAC X RPOS 30 PCT The reference value is shifted by 30 towards the left Manual operation See X Axis Reference Position on page 153 DISPlay WINDow lt n gt TRACe lt t gt X SCALe RVALue lt RVal gt This command defines the reference value for the x axis for statistical result displays For all other result displays this command is only available as a query Setting parameters lt RVal gt numeric value Reference value for the x axis Manual operation See X Axis Reference Value on page
394. ise you would never be able to find the pattern within the result range Remote command CALCulate n TRACe t ADJust ALIGnment OFFSet on page 316 Symbol Number at Reference Start Defines the number of the symbol which marks the beginning of the alignment refer ence source burst capture buffer or pattern The result of the current setting is dis played in the visualization area of the dialog box In effect this setting defines an offset of the x axis in addition to the one defined for the signal structure see Offset on page 141 Note When you define the Symbol Number at Reference Start remember to take the offset defined for the signal structure into consideration see Offset on page 141 The Symbol Number at Pattern Start refers to the first symbol of the pattern offset not the first symbol of the pattern Remote command DISPlay WINDow n TRACe t X SCALe VOFFset on page 317 5 9 Demodulation Settings During demodulation of the vector signal some undesired effects that may occur during transmission can be compensated for Furthermore you can influence the synchroni zation process e Demodulation ComperiSation e iced tete to ella sre Pales 176 e Advanced Demodulation 0 180 Demodulation Settings 5 9 1 Demodulation Compensation o Note that compensation for all the liste
395. it The data section starts with the keyword Trace lt gt n number of stored trace followed by the measured data in one or several columns depending on the result type which are also separated by a semico lon If several traces in several windows are exported to one file the data for each window is listed subsequently Within the data for a single window the data for the individual traces is listed subsequently User Manual 1176 8516 02 06 421 ASCII File Export Format for VSA Data For details on which data is stored for which result display see TRACe lt n gt DATA on page 374 Table 1 5 ASCII file format for VSA trace data export File contents Description Header Type FPS Instrument model Version 1 40 Firmware version Date 01 Apr 2012 Date of data set storage Header section for individual window Screen 1 Window name Points per Symbol 4 x Axis Start 13 sym Points per symbol Start value of the x axis x Axis Stop 135 sym Stop value of the x axis y per div 0 22000000000000003 Y axis range per division Ref value y axis 10 00 dBm Y axis reference value Ref value position 100 96 Y axis reference position Start of ResultRange in Capture Buffer 6400 sym Number of symbol at which exported capture buffer range begins Header section for individual trace Trace 1 First trace Meas
396. l transition Fig 4 15 Constellation diagram for 37 8 8PSK before rotation including the symbol mapping for EDGE Symbol Mapping Fig 4 16 I Q symbol stream after 3778 rotation in I Q plane if the symbol number 7 is transmitted six times in a row Fig 4 18 Constellation diagram for 74 QPSK Natural including the symbol mapping Symbol Mapping 4 3 3 Differential PSK With differential PSK the information is represented in the phase shift between two consecutive decision points The absolute position of the complex sample value at the decision point does not carry information In the physical constellation diagram the constellation points at the symbol decision points obtained after ISI free demodulation are shown as with common PSK meth ods This diagram corresponds to the display on the analyzer The position of the con stellation points is standard specific For example some QPSK standards define the constellation points on the diagonals while other standards define the coordinate axes In table 4 3 the symbols are assigned to phase shifts The QPSK INMARSAT map ping corresponds to simple QPSK with phase differential coding Tables table 4 4 and table 4 5 show two types of differential BPSK modulation Differential coding according to VDL is shown in table 4 6 It can be used for modula tion types with 3 bits symbol e g 8PSK Other types of modulation using differential coding method are described
397. late n STATistics SCALe Y UNIT sseesssssssssseseseseeenne rnt 298 CALCulatesn STATistics SCALe Y UPPOrF eerte a tct epo cer ee ete uero 297 CALCulate n TRACe t ADJust ALIGnment OFFSet essen CALCulate lt n gt TRACe lt t gt ADJust ALIGnment DEFault CALCulate lt n gt TRAGest gt ADJUStE VALUe 2 rtr netter ratur tr eh tr eorr ter tla ra eh CALC latesnz M GAL Gulate lt n gt UNITZANGL 6 et trot then Ce tern d eee en TERRE ER CALEGulatesm X UNIT TIM E perra ei be t ere eoa coe bata nig DEC I De ERR ERR ET RS GAL Gulate sina aoi SR DISPlay WINDow n ITEM LINE VALue BISPlay WINDowsri PRATe JALU TO scias enata top oS Kore thee bra ete conet sir ena aeui DISPlayEWINDowsriz PRATe DISPlayEWINDOW SnP SIZE itr erae trt tenente BISPlay WINDowsn TRACE SYMBOL tutae Y FOE nt FE tnter DISPlayEWINDowsri7 TRACe t MODE tuere rte tener nth e Ron neri rere DISPlay WINDow lt n gt TRACe lt t gt X SCALe PDIVision DISPlay WINDow lt n gt TRACe lt t gt X SCALe RPOSition DISPlay WINDow n lt gt 5 2 2
398. lated based on their absolute values User Manual 1176 8516 02 06 49 Result Types in VSA Again the Rho value is handled differently Here the 5 Percentile is displayed since the lowest Rho value represents the worst case Remote commands LAY ADD 1 BEL MACC to define the required source type see LAYout ADD WINDow page 359 CALC FORM RSUM to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA on 374 and chapter 11 9 2 5 Result Summary on page 376 CALC MARK FUNC DDEM STAT lt parameter gt to query individual parameter values see chapter 11 9 3 Retrieving Parameter Val ues on page 377 Result Summary Individual Results The Result Summary can display either all or only a single modulation accuracy parameter Only the most important parameters can be displayed individually namely those for which modulation accuracy limits can be defined see Limit Value on page 200 Individual results are selected for display by clicking in the Result Summary table header A Table Configuration dialog box is displayed in which you can select the parameter to be displayed Result Summa Results to be displayed EVM RMS Phase Errors RMS Phase Error Peak Magnitude Error RMS Magnitude Error Peak Carrier Frequency Error IQ Offset
399. lation Errors 4 5 Signal Model Estimation and Modulation Errors This section describes the signal and error models used within the VSA application The estimation algorithms used to quantify specific modulation errors are then outlined The descriptions vary depending on the modulation type e PSK QAM and c toe ehe th reete remet cree nes 100 e Pea te Ex tese ve E 110 4 5 1 PSK QAM and MSK Modulation 4 5 1 4 Error Model Modelling Modulation Errors Modulated RF Signal Amplitude Quadrature Inbalance Offset VQ Offset Distorsion Fig 4 50 Modelling Modulation Errors The measured signal model for PSK QAM and MSK modulation is shown in fig ure 4 50 and can be expressed as MEAS 5 REF C j Qo REF C c 07970 where t and REF t the and quadrature component of the reference signal g and the effects of the gain imbalance c and the effects of an offset 9 the quadrature error a the amplitude droop Signal Model Estimation and Modulation Errors fo the carrier frequency offset the carrier phase offset C the timing offset n t a disturbing additive noise process of unknown power 4 5 1 2 Estimation The VSA application includes two synchronization stages The first s
400. le Reference Signal Generation The ideal reference signal is generated based on the detected symbols and the specifi cations of the signal model i e the modulation scheme and the transmit filter Tx filter Measurement Filtering Both the measurement signal and the reference signal are filtered with the specified measurement filter Synchronization In this stage the measurement signal and the reference signal are correlated For PSK QAM and MSK modulated signals an estimation algorithm is used in order to obtain estimates for the signal amplitude signal timing carrier frequency error phase error offset gain imbalance quadrature error and the amplitude droop Alterna tively it is possible to disable the estimation algorithm For FSK modulated signals estimates for the signal amplitude signal timing carrier frequency error FSK deviation error and the carrier frequency drift are calculated The measurement signal is subsequently corrected with these estimates Compensation for FSK deviation error and carrier frequency drift can be enabled or disabled For more information on synchronization see chapter 4 5 1 2 Estimation on page 101 chapter 5 9 2 Advanced Demodulation Synchronization on page 180 Result Display The selected measurement results are displayed in the window s Configuration of the windows can be performed via the Window Configuration dialog see chapter 6 5 Display and Window Configuratio
401. les are captured overlapping capture ranges with a size of 256 000 samples each are created ber of samples per symbol for example for the default sample rate of 4 symbol rate the maximum number of symbols to be captured is 50 000 000 see also chapter 4 2 Sample Rate Symbol Rate and Bandwidth on page 63 2 maximum number of symbols that be captured depends on the specified num Only one capture range at a time can be displayed in the result displays based on the capture buffer except for the Magnitude Overview Absolute You can scroll through the different ranges using the Select Result Rng function When the selected result range moves outside the current capture range the right edge of the current result range is displayed in the center of the next capture range Overview vs details While the Magnitude Absolute and other result displays based on the capture buffer Real Imag I Q Vector chapter 3 2 11 Frequency Absolute on page 29 can only display a single capture range at a time the Magnitude Overview Absolute dis plays the entire capture buffer at once However the overview trace is restricted to 25 000 points If necessary the captured samples are mapped to 25 000 display points using an autopeak detector for display in the Magnitude Overview Absolute diagram Thus this result display is not suitable to detect transient effects or analyze individual symbols closely For these purposes the
402. lp is embedded in the instrument s firmware It offers quick context sen sitive access to the complete information needed for operation and programming Online help is available using the icon on the toolbar of the R amp S FPS Getting Started This manual is delivered with the instrument in printed form and in PDF format on the CD ROM It provides the information needed to set up and start working with the instrument Basic operations and handling are described Safety information is also included The Getting Started manual in various languages is also available for download from the Rohde amp Schwarz website on the R amp S FPS product page at http www rohde schwarz com product FPS html User Manuals User manuals are provided for the base unit and each additional firmware application The user manuals are available in PDF format in printable form on the Documenta tion CD ROM delivered with the instrument In the user manuals all instrument func tions are described in detail Furthermore they provide a complete description of the remote control commands with programming examples The user manual for the base unit provides basic information on operating the R amp S FPS in general and the Spectrum application in particular Furthermore the soft ware functions that enhance the basic functionality for various applications are descri bed here An introduction to remote control is provided as well as information on main
403. lso defined for the peak value and vice versa However the limit check can be enabled individually for cur rent or peak values 5 Enable the Check option for each result type to be included in the limit check 6 If necessary define limits and enable the limit check for the mean values of the dif ferent result types on the Mean tab 7 f necessary enable the limit check for the peak values of the different result types on the Peak tab 8 Toreset the limits to their default values press Set to Default 9 Enable the Limit Checking On option or press the ModAcc Limits On softkey in the Limits menu The limit check is performed immediately on the current modulation accuracy mea surement results and for all subsequent measurements until it is disabled The results of the limit check are indicated by red or green values in the result sum mary 8 3 3 How to Export the Trace Data to a File The measured data can be stored to an ASCII file either as raw data directly from the capture buffer or as displayed in the diagrams evaluated trace data Optionally a header can be included with additional information on the used measurement settings User Manual 1176 8516 02 06 226 How to Analyze the Measured Data 1 Press the TRACE key and select the Trace Export Config softkey 2 Define which type of data to export raw or trace By default trace data is expor ted 3 Optionally enable the header infor
404. lt n gt TRACe lt t gt Y SPACing on page 300 For phase diagrams CALCulate lt n gt UNIT ANGLe on page 298 For statistics CALCulate n STATistics SCALe Y UNIT on page 298 For equalizer group delay diagrams CALCulate lt n gt Y UNIT TIME on page 298 Signal Capture The Signal Capture settings define how much how and when data is captured from the input signal R amp S FPS K70 Configuration The Signal Capture settings are displayed when you do one of the following e Select the Signal Capture button from the Overview e Select the Signal Capture softkey from the main VSA menu Data RT H 155 M S 157 noe 161 5 6 1 Data Acquisition The Data Acquisition settings define how much and how data is captured from the input signal A live preview of the signal in the capture buffer with the current settings is displayed in the preview area at the bottom of the dialog box The preview area is not editable directly The Data Acquisition settings are displayed when you do one of the following e Select the Signal Capture button from the Overview e Select the Signal Capture softkey from the main VSA menu gt Data Acquisition Trigger f Capture Length GUCE 8000 0 sym sym 2 083 ms Sample Rate 4 Symbol Rate 15 36 MHz Maximum Bandwidth Auto Usable I Q Bandwidth 12 288 M
405. lt n gt TRACe lt t gt Y SCALe AUTO 330 DISPlay WINDow n TRACe t Y SCALe AUTO ALL esee 330 SENSe ADJust CONFigure DURatioh 2 2 ccrte iaia 330 5 0 nennen 330 Configuring VSA _ 331 5 331 SENSeTABJUsEEEWel c gente ta 332 SENSETIDDEMod PRESSERLIVe Fea aea nei rre educ eoe 332 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO ONCE Automatic scaling of the y axis is performed once then switched off again for all traces lt t gt is irrelevant Usage SCPI confirmed Manual operation See Auto Scale Once Auto Scale Window on page 151 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO ALL Automatic scaling of the y axis is performed once in all windows then switched off again Usage Event Manual operation See Auto Scale All on page 189 SENSe ADJust CONFigure DURation Duration In order to determine the ideal reference level the R amp S FPS performs a measurement on the current input d
406. luation Range The evaluation range defines the symbols from the result range that to be included in the evaluation of specific parameters e g error vectors For example while you may want to display the ramps of a burst and thus include them in the result range they do not contribute to the error vectors or power levels Thus you would not include them in the evaluation range Capture Length Fig 4 63 Schematic overview of Capture Length Result Range and Evaluation Range The determined result and evaluation ranges are included in the result displays where useful to visualize the basis of the displayed values and traces Result Range The result range defines the symbols from the capture buffer that are to be demodula ted and analyzed together In some cases the data in the capture buffer contains parts that are not relevant for the evaluation task at hand Thus you can exclude them from the result range see chapter 5 8 Result Range Configuration on page 173 Result range display The result ranges are indicated by green bars along the time axis of the capture buffer result diagrams R amp S FPS K70 Measurement Basics Mag CapBuf 20 dBm 40 d amp m aiid iM a ui G Start 0 sym Fig 4 64 Result ranges for a burst signal Result displays whose source is not the capture buffer are based on a single result range such as the EVM vs Time display or the data in the Current c
407. ly you define the range to be displayed in each of the 10 divisions of the display which determines the total range to be displayed on the x axis 1 Focus the result window 2 Select AMPT gt Scale Config gt Reference Value 3 Enter a reference value on the x axis in the current unit 4 Define the range to be displayed per division total range 10 The x axis is adapted so that it displays the defined range with the reference value at the specified position R amp S FPS K70 How to Perform Vector Signal Analysis Example If you want to analyze the probabilities of occurrence for errors greater than 95 enter the reference value 95 Start 95 0 Stop 100 0 Fig 8 4 Defining the x axis scaling using a reference point To define the x axis scaling automatically 1 Focus the result window 2 Select AMPT gt XScale Config gt Auto Scale The x axis is adapted to display the current results optimally only once not dynamically To define the y axis range manually With this method you define the upper and lower limits of the displayed probability range Values on the y axis are normalized which means that the maximum value is 1 0 If the y axis has logarithmic scale the distance between max and min value must be at least one decade 1 Focus the result window 2 Select AMPT gt YScale Config gt Y Axis Min Value 3 Enter the lower limit in the current unit 4 Select AMPT gt YSc
408. m minimum to the left of the current peak Absolute Determines the next maximum minimum to either side of the current peak Right Determines the next maximum minimum to the right of the current peak Remote command chapter 11 7 2 2 Marker Search and Positioning Settings on page 344 Real Imag Plot Defines whether marker search functions are performed on the real or imaginary trace of the Real Imag measurement Remote command CALCulate lt n gt MARKer lt m gt SEARch on page 347 Search Limits Left Right If activated limit lines are defined and displayed for the search Only results within the limited search range are considered Remote command CALCulate lt n gt MARKer lt m gt X SLIMits STATe on page 348 CALCulate lt n gt MARKer lt m gt X SLIMits LEFT on page 347 CALCulate n MARKer m X SLIMits RIGHT on page 348 Markers 6 3 3 Marker Positioning Functions The following functions set the currently selected marker to the result of a peak search These functions are available as softkeys in the Marker To menu which is displayed when you press the gt key sace te eicere a veretur Se ooo d t Dex Dad ea enu ele alt ca et 198 Search PER EC 198 Max Peak eL EEEE 198 Searc anaiai aaa aD aa daai eaei arpaan di anini 198 Search Next
409. matical expression Calculation in R amp S FPS Mean idx arg max x m 1 E M 1 x n Xy a ty Hes with Xo 0 m Su xy if Burl with Xy xy aif lt lul with 0 Formulae Mathematical expression Calculation in R amp S FPS StdDev oy Bum I with E oy Dirt M with 0 95 ile X95 M lt 0 95 Pr denotes the probability Sorting the values and giving the 95 ile A 6 4 Trace Averaging The index m represents the current evaluation M is the total number of evaluations In single sweep mode M coresponds to the statistics count The index s represents the st sample within the trace If the measurement results are represented in logarithmic domain the average opera tion is performed on the linear values The result is then subsequently converted back into logarithmic domain Measurements Calculation in R amp S FPS RMS Average s M Error Vector Magnitude EVM Meas Ref magnitude Capture Buffer magnitude _ EET a a Linear Average s M measurements where trace averaging is possible except for the measurements listed for RMS averaging 1 Xs M M Xs M A 6 5 Analytically Calculated Filters The following filters are calculated during runtime of the unit and as a fun
410. mation points per symbol 182 Known data 124 Normalization 2 181 Offset EVM 184 lip cc 88 REMOTE 318 Synchronization 180 183 Diagram footer information 13 Differential PSK DPSK Symbol MAPPING ott etas 73 Digital standards Assigned patterns 169 Assigning patterns 170 Configuration 129 Performing measurement according to 210 Predefined teet 412 keen 2 273 Removing assigned patterns 170 Selecting ee 130 Softkey 130 VSA measurermlerils 5 129 Display c ront tritt rennen 201 InfOrmatior eee ertet erm 11 Points per symbol 121 203 425 427 Drop out time BI 161 Duplicating Measurement channel remote 270 E EDGE Filters frequency response 433 Measurement example Electronic input attenuation Equalizer P estate Data SOUL CB eot ro et tinis qian Loading zu eit an MSRA mode iss Result types an estre no peter eene eitis EI
411. mation to be included 4 To export the traces in all windows select Export Trace to ASCII File for all Win dows To export the traces only for the currently selected window select Export Trace to ASCII File for Specific Window To export the data from another window select it from the Specifics for list then export again In either case all traces of the selected window s are exported 5 Define a name and storage location and select OK The data is stored in a file and can be analyzed in an external application g 9 1 9 2 9 2 1 Connecting the Transmitter and Analyzer Measurement Examples Some sample measurements for the digital GSM and EDGE standards provide a quick introduction to typical vector analyzer measurements The individual measurements are in logical order and are meant to familiarize you gradually with the measurements required of general vector signal analysis The following equipment is required in addition to the R amp S FPS with option R amp S FPS K70 e 1 test transmitter GSM compatible for Measurement 2 preferably R amp S SMW200A 1412 0000 02 with the digital standard option GSM EDGE order number 1413 3684 02 1 RF cable with 2 male N connectors 2 power cables Transmitter operation is only described as far as required for performing the measure ments For more details on the measurements refer to the test transmitter documenta tion Connecting the Transmitter an
412. me can be displayed in the Magnitude Absolute result display To scroll through the samples in different ranges use the Sweep Select Result Rng function or directly after a sweep turn the rotary knob When you scroll in the dia gram the right edge of the current range or the selected result range is displayed in the center of the next range if possible To display the entire capture buffer with all ranges in one diagram use the Magnitude Overview Absolute result display Note that trace modes that calculate results for several sweeps Average MinHold MaxHold are applied to the individual ranges and thus may not provide useful results in this result display For more information on result ranges see chapter 4 8 Capture Buffer Display on page 122 In the Magnitude Absolute result display the actual signal amplitude is displayed User Manual 1176 8516 02 06 39 R amp S9FPS K70 Measurements and Result Displays 3 2 22 Mag 8 9 with tzn Tp the duration of one sampling period at the defined sample rate defined by the dis play points per symbol parameter see Display Points Sym on page 203 Available for source types e Capture Buffer e Meas amp Ref Signal Displays the actual signal amplitude for the selected evaluation range 3 Mag CaptureBuffer 8000 sym Fig 3 12 Result display Magnitude Absolute for capture buffer data Remote commands LAY ADD 1
413. measurement is started immediately with the default settings INS Trament OREate DUPLIGal a iere rne etra vue taxed e tnra dax mede 270 INSTrument CREate NEW 2 riore nanen lauren 270 INSTrument GREate REPLace iiiter annt EMO n danak NR DR 270 2 ee tat ecu 271 INS froment US T RETE 271 Activating Vector Signal Analysis INST BRE SE GTI 2 2 oderint cera du daban ea 272 272 5 273 INSTrument CREate DUPLicate This command duplicates the currently selected measurement channel i e creates a new measurement channel of the same type and with the identical measurement set tings The name of the new channel is the same as the copied channel extended by a consecutive number e g Spectrum gt Spectrum 2 The channel to be duplicated must be selected first using the INST SEL command Example INST SEL Spectrum INST CRE DUPL Duplicates the channel named Spectrum and creates a new measurement channel named Spectrum 27 Usage Event INSTrument CREate NEW lt ChannelType gt lt ChannelName gt This command adds an additional measurement channel The number of measurement channels you can conf
414. measurement can be selected from this list This list can be extended by patterns that are already available in the R amp S FPS Newly created patterns can also be added to the list 4 4 3 Demodulation and Symbol Decisions This stage operates on the result range and aims to make the correct symbol deci sions The algorithm is illustrated in figure 4 45 using the example of a QPSK modula tion After timing and scaling recovery a frequency offset and phase offset estimator is employed After this coarse synchronization the VSA application makes symbol decisions i e recovers which symbols were transmitted by the device under test DUT Typically the employed estimators are non data aided NDA estimators This means that they operate on an unknown data sequence Since the local oscillators LO of the transmitter device under test and the receiver R amp S FPS are normally not coupled User Manual 1176 8516 02 06 93 Overview of the Demodulation Process their phase offset with respect to each other is unknown The unknown transmission delay between DUT and R amp S FPS adds a further unknown phase offset Due to this unknown phase offset the result of the demodulation can be ambiguous with respect to the absolute phase position because of the rotational symmetry of e g a PSK constellation For example in the case of non differential QPSK modulation the measurement signal the reference signal and the decided I Q symbols may
415. ment Filter Auto setting is not enabled Predefined An overview of available measurement filters is provided in chapter A Filter gt 3 2 Measurement Filters on page 420 User User defined filter Define the filter using the Load User Filter function or the SENSe DDEMod MFILter USER command For more information on user defined filters see chapter 4 1 5 Cus tomized Filters on page 61 None No measurement filter is used Remote command SENSe DDEMod MFILter STATe on page 327 To turn off the measurement filter SENSe DDEMod MFILter USER on page 328 To use a user defined filter SENSe DDEMod MFILter NAME on page 327 To define the name of the measurement filter Load User Filter Type Opens file selection dialog box to select the user defined measurement filter to be used This setting is only available if User is selected as the Filter Type For detailed instructions on working with user defined filters see chapter 8 2 1 How to Select User Defined Filters on page 213 Remote command SENSe DDEMod MFILter USER on page 328 Alpha BT Type Defines the roll off factor Alpha or the filter bandwidth BT The roll off factor or filter bandwidth are available for RC RRC and Gauss filters 5 11 Evaluation Range Configuration If the measurement mode is automatically selected according to the transmit filter this setting is identical to the Alpha BT
416. ment section of the R amp S FPS User Manual Remote command MMEMory STORe lt n gt 10 STATe on page 391 MMEMory STORe lt n gt 1IQ COMMent on page 390 7 2 How to Export and Import Data data can only be exported in applications that process 1 0 data such as the Analyzer or optional applications Capturing and exporting data 1 Press the PRESET key 2 Press the MODE key and select the IQ Analyzer or any other application that supports data Configure the data acquisition Press the RUN SINGLE key to perform a single sweep measurement Select the Save icon in the toolbar Select the Export softkey In the file selection dialog box select a storage location and enter a file name o o Select Save The captured data is stored to a file with the extension iq tar Importing 1 data 1 Press the MODE key and select the IQ Analyzer or any other application that supports data If necessary switch to single sweep mode by pressing the RUN SINGLE key Select Open icon in the toolbar Select the I Q Import softkey Select the storage location and the file name with the iq tar file extension BR Select Open The stored data is loaded from the file and displayed in the current application Previewing the data in a web browser How to Export and Import I Q Data The iq tar file format allows you to previe
417. mmand defines the power offset value assigned to the reference position Parameters Value RST 0 dBm coupled to reference level Example DISP TRAC Y RVAL 20dBm Sets the power value assigned to the reference position to 20 dBm Manual operation See Reference Value on page 152 DISPlay WINDow lt n gt TRACe lt t gt Y SPACing lt ScalingType gt This command selects the scaling of the y axis for all traces lt t gt is irrelevant Configuring VSA Parameters lt ScalingType gt LOGarithmic Logarithmic scaling LiNear Linear scaling in LDB Linear scaling in the specified unit PERCent Linear scaling in RST LOGarithmic Example DISP TRAC Y SPAC LIN Selects linear scaling in 96 Usage SCPI confirmed Manual operation See Y Axis Unit page 154 11 5 3 Signal Capture The signal capture commands define how much how and when data is captured from the input signal MSRA operating mode In MSRA operating mode only the MSRA Master channel actually captures data from the input signal The data acquisition settings for the VSA application in MSRA mode define the application data extract and analysis interval For details on the MSRA operating mode see the R amp S FPS MSRA User Manual The tasks for manual operation are described in chapter 5 6 Signal Capture on page 154 ISENSe TDDEMGod PRATE a aee eec E 301 I SENSe DDEMod RPENGIthAD TO
418. mmand queries the results of the reference deviation of FSK modulated signals Query parameters lt type gt lt none gt Measurement deviation for current sweep AVG Average FSK measurement deviation over several sweeps RPE Peak FSK measurement deviation over several sweeps SDEV Standard deviation of FSK measurement deviation PCTL 95 percentile value of FSK measurement deviation Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic GIMBalance lt type gt This command queries the results of the Gain Imbalance error measurement of digital demodulation The output values are the same as those provided in the Modulation Accuracy table Query parameters lt type gt lt none gt Gain imbalance error for current sweep AVG Average gain imbalance error over several sweeps RPE Peak gain imbalance error over several sweeps SDEV Standard deviation of gain imbalance error PCTL 95 percentile value of gain imbalance error Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic QIMbalance type This command queries the results of the imbalance error measurement of digital demodulation Retrieving Results Query parameters type none imbalance error for current sweep Average imbalance error over several sweeps RPE Peak imbalance error over several sweeps SDEV Standard deviation of imbalance error PCTL 95 percentile value of
419. mmand to move from one result range to the next e Retrieving Trace Data and Marker 371 e Measurement Results for TRACe lt n gt DATA lt gt 375 e IRetreving Parameter Values cento crt ce tite eben te edd 377 e Retrieving Limit Check Results dene ei nete e 388 Retrieving Trace Data and Marker Values In order to retrieve the trace and marker results in a remote environment use the fol lowing commands gt lt gt 371 lt gt lt gt 371 GALOGulate n MARKersmo Y uelis sende Re ARR 372 lt gt lt gt 5 5 372 lt gt lt gt 372 FORMatDEXPortDSEPUaLralor 1 2 ea a A e RID A RT iR 373 FORMat 220 hot e pred ad ae 373 cav oe oou b ca 373 MMEMory STORe sn TRAQGS eue 373 ISE
420. modulates the selected pattern according to the transmit filter Tx filter and the modulation scheme Subsequently it searches the capture buffer for this pat tern i e the waveform of the pattern It is assumed that patterns can only appear within bursts i e the pattern search range is limited to the bursts detected by the burst search stage If the burst search is switched off the whole capture buffer is searched for the pattern A list of all detected patterns is passed on to the next processing stage It is important to note that the VSA application can only search for one pattern at a time The pattern search can be switched on or off via the Pattern Search dialog see Enabling Pattern Searches on page 167 Detected patterns are indicated by a green background in the symbol table If during demodulation individual symbols do not match the pattern after all these symbols are indicated by a red frame Extraction of Result Range The result range can be aligned to a burst a pattern or simply the start of the capture buffer see Reference on page 174 Within this stage the result range is cut from the capture buffer starting at a point that is specified by the user e g the start of a detected burst The VSA application automatically takes into account filter settling times by making the internal buffers sufficiently longer than the selected result range Demodulation amp Symbol Decisions This
421. modulation the value range is from 0 to 7 The degree of modulation belongs to the pattern and is set using the DDEM SEAR SYNC NST command see SENSe DDEMod SEARch SYNC NSTate on page 314 Configuring VSA Setting parameters Data string Four values represent a symbol hexadecimal format The value range of a symbol depends on the degree of modulation With a degree of modulation of 4 all symbols have a value range of 0000 0001 0002 0003 With a degree of modulation of 8 0000 0001 0002 0003 0004 0005 0006 0007 Example DDEM SEAR SYNC DATA 00010000FFFF Defines the pattern data Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Edit on page 170 See New on page 170 See Symbols on page 173 SENSe DDEMod SEARch SYNC NAME Name This command selects a sync pattern for editing or for a new entry Setting parameters Name string Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Edit on page 170 See New on page 170 See Name on page 172 SENSe DDEMod SEARch SYNC NSTate lt NState gt This command selects the degree of modulation number of permitted states The pat tern must have been selected before using using SENSe DDEMod SEARch SYNC NAME on page 314 The n
422. mple Rate Symbol Rate and Bandwidth on page 63 Remote command SENSe DDEMod SRATe on page 282 Signal Description Transmit Filter Type Defines the type of transmit filter An overview of available transmit filters is provided in chapter A 3 1 Transmit Filters on page 419 For more information on transmit filters see chapter 4 1 3 Modulation and Demodula tion Filters on page 58 Remote command SENSe DDEMod TFILter NAME on page 283 To define the name of the transmit filter to be used 5 5 DDEMod TFILter STATe on page 283 To switch off the transmit filter SENSe DDEMod TFILter USER on page 284 To select a user defined filter Load User Filter Transmit Filter Type Opens file selection dialog box to select the user defined transmit filter to be used Note If a user defined transmit filter is selected and the measurement filter is defined automatically see Using the Transmit Filter as a Measurement Filter Auto on page 186 a Low ISI measurement filter according to the selected user filter is cal culated and used For details see chapter 4 1 5 Customized Filters on page 61 For detailed instructions on working with user defined filters see chapter 8 2 1 How to Select User Defined Filters on page 213 Remote command SENSe DDEMod TFILter USER on page 284 SENSe DDEMod TFILter NAME on page 283 Alpha BT Defines the roll off factor Alph
423. mum EVM over all display points over several sweeps Query only R amp S FPS K70 Remote Commands for VSA CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic SRERror lt type gt This command queries the symbol rate error Query parameters lt type gt PEAK AVG SDEV PCTL TPEak RPEak PAVG PSDev PPCTI lt none gt Symbol rate error for current sweep AVG Average symbol rate error over several sweeps RPE Peak symbol rate error over several sweeps SDEV Standard deviation of symbol rate error PCTL 95 percentile value of symbol rate error Usage Query only 11 9 4 Retrieving Limit Check Results The modulation accuracy parameters can be checked against defined limits The fol lowing commands are required to query the results of these limit checks CALCulate lt n gt LIMit MAC Curacy CFERror CURRent RESult CALCulate lt n gt LIMit MACCuracy CFERror MEAN RESult CALCulate lt n gt LIMit MAC Curacy CFERror PEAK RESult CALCulate lt n gt LIMit MAC Curacy EVM PCURrent RESult CALCulate lt n gt LIMit MAC Curacy EVM PMEan RESult CALCulate lt n gt LIMit MACCuracy EVM PPEak RESUIt CALCulate lt n gt LIMit MACCuracy EVM RCURrent RESult CALCulate lt n gt LIMit MACCuracy EVM RMEan RESult CALCulate lt n gt LIMit MAC Curacy EVM RPEak RESult CALCulate lt n gt LIMit MAC Curacy FDERror CURRent RESult CALCulate lt n gt LIMit MACCuracy FDERror MEAN RESult CALCulate lt n gt LIMi
424. n on page 201 Burst Search The burst search is performed only if it is switched on Otherwise this stage is skipped It is recommended that you switch the burst search on if the signal is bursted This R amp S FPS K70 Measurement Basics ensures that all internal estimators are operated in time ranges where the burst power ramping is up In order to eliminate amplitude variations caused by noise or the modulation itself the instantaneous power of the whole capture buffer is computed and then a moving aver age filter is applied The length of this filter is automatically determined with the help of the user settings The filtered power of the capture buffer is subsequently compared to an automatically chosen threshold and the rising and falling edges of bursts are identified With the help of the detected edges and some further processing it is possible to decide whether the burst candidates comply with the user settings All bursts must have a length between Min Burst Length Search Tolerance and Max Burst Length Search Tolerance to be accepted See Burst Settings on page 140 and chapter 5 7 1 Burst Search on page 164 for a more detailed description of these parameters gt Min Burst Length Min Gap Length Max Burst Length Fig 4 43 Burst Search parameters You can influence the robustness of the burst search directly by entering the correct minimum
425. n R amp S FPS K70 identical to the FSK DEV ERROR in R amp S FSQ K70 Solution The FSK deviation error in the R amp S FPS K70 is calculated as the difference between the measured frequency deviation and the reference frequency deviation as entered by the user see FSK Ref Deviation FSK only on page 137 What is referred to as the FSK DEV ERROR in the R amp S FSQ K70 is calculated differently see the R amp S FSQ K70 Software Manual and is comparable to the Freq Err RMS in the R amp S FPS K70 However while the FSK DEV ERROR in the R amp S FSQ K70 is given in Hz the Freq Err RMS in the R amp S FPS K70 is given in percent i e relative to the FSK Meas Devi ation User Manual 1176 8516 02 06 260 R amp S FPS K70 Optimizing and Troubleshooting the Measurement Problem The PSK QAM Signal shows spikes in the Frequency Error result dis play Spectrum VSA Ref Level 22 00 dBm Mod QPSK SR 270 833 kHz m el Att 10 0 dB Freq 1 0 GHz ResLen 200 SGL TRG EXT A Freq Error Abs 1Clrw Phase Error Start 3 sym Stop 203 sym Start 3 sym Stop 203 sym D Vector I Q Meas amp Ref 1M Clrw Stop 5 13 did 09 30 16 Solution These spikes are usually uncritical are caused by zero transitions in the Plane Question The y axis unit for the spectrum of the measurement signal can be chosen to be dB What level is this relative to Answer Spectrum Reallmag Meas amp Ref calculates the FFT of the result Re
426. n STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy PERRor PPEak STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy PERRor RCURrent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy PERRor RMEan STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy PERRor RPEak STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy RHO CURRent STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy RHO MEAN STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy RHO PEAK STATe lt LimitState gt CALCulate lt n gt LIMit MACCuracy lt ResultType gt lt LimitType gt STATe lt LimitState gt This command switches the limit check for the selected result type and limit type on or off User Manual 1176 8516 02 06 350 Suffix lt ResultType gt lt LimitType gt Setting parameters lt LimitState gt Example Manual operation Analysis CFERror Carrier Frequency Error EVM Error Vector Magnitude FERRor Frequency error FSK only FDERror Frequency deviation error FSK only MERRor Magnitude Error OOFFset Offset PERRor Phase Error RHO Rho For CFERor OOFFset RHO CURRent MEAN PEAK For EVM FERRor MERRor PERRor PCURRent Peak current value PMEan Peak mean value PPEak Peak peak value RCURRent RMS current value RMEan RMS mean value RPEak RMS peak value ON OFF Activates a limit check for the selected result and limit type RST OFF CALC2 FEED
427. n be defined in the following ways e manually by defining the range size reference values and positions e automatically according to the current results To define the scaling manually using a reference point With this method you define a reference value and a position at which this value is to be displayed on the y axis 1 Focus the result window Select AMPT YScale Config Y Axis Reference Value 2 3 Enter a reference value for the y axis in the current unit 4 Select AMPT gt YScale Config gt Y Axis Reference Position 5 Enter the position at which this value is to be displayed on the y axis The position is a percentage of the entire length where 100 refers to the top edge 6 Select AMPT gt YScale Config gt Y Axis Range Example If you want the to analyze errors greater than 95 you can define the y axis range as 5 and position the y axis to start at 9596 To do so enter the reference value 95 96 and the reference position 096 1 Clrw 2 Clrw Start 151 0 sym Stop 299 0 sym Fig 8 3 Defining the y axis scaling using a reference point To define the scaling automatically 1 Focus the result window pnmum EIN E NM NUUS S User Manual 1176 8516 02 06 223 How to Analyze the Measured Data 2 Select AMPT gt Y Axis Auto Scale The y axis is adapted to display the current results optimally only once not dynamically 8 3 1 2 How to Scale St
428. n itself is independent of the currently displayed tab For details on the Sequencer function see the R amp S FPS User Manual Understanding the Display Information The following figure shows a measurement diagram during analyzer operation All dif ferent information areas are labeled They are explained in more detail in the following sections R amp S FPS K70 Welcome to the Vector Signal Analysis Application MultiView 33 Spectrum VSA 2 Ref Level 0 m Std 3 WCDMA SR 4 MHz SGL Att 108 Frs 1325 GHz ResLen 20 Stat Count 10 1 Const 1 0 D 2 1 2 Result Summary Current ec EVM RMS 100 00 Peak 100 00 MER NMS 0 00 Peak 0 00 Phase Frror RMS 103 95 Peak 179 82 Magnitude Frror RMS 100 00 Peak 100 00 Carrier Frequency Frror 445021 50 Rho 0 000 008 1 0 Offset 36 57 1 0 Tmbalance 0 08 Gain Tmbalance 46 60 Quadrature Error 159 53 5 Stop 3 LIII 0 000 000 Buffer Hexadecimal yog og qure 0 16 32 18 64 80 47796 128 160 176 19 208 Start 0 sym Stop 8000 sym 224 1 Channel bar for firmware and measurement settings 2 3 Window title bar with diagram specific trace information 4 Diagram area 5 Diagram footer with diagram specific information depending on measurement application 6 Instrument status bar with error messages progress bar and date time display MSRA operating mode In MSRA opera
429. n page 376 3 2 12 Frequency Relative The instantaneous frequency of the signal source The results are normalized to the symbol rate PSK and QAM modulated signals the estimated FSK deviation FSK modulated signals or one quarter of the symbol rate MSK modulated signals FREQ lt ZMEAS 2 z dt with and duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 can also be used for the PSK QAM modulations See also the note for chapter 3 2 11 CD This measurement is mainly of interest when using the MSK or FSK modulation but Frequency Absolute on page 29 Available for source types e Meas amp Ref Signal 3 FreqRel Meas amp Ref 1M 49 sym Fig 3 9 Result display Frequency Relative pum EIN NDA EN V UU User Manual 1176 8516 02 06 31 Result Types in VSA Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow on page 359 CALC FORM to define the result type see CALCulate lt n gt FORMat on 366 DISP TRAC Y MODE REL to define relative values see DISPlay WINDowc n TRACe t Y SCALe MODE on page 370 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 3 2 13 Freq
430. nce deviation error is corrected in the reference frequency trace This ensures that the frequency deviation in the measured frequency trace corresponds to that of the originally measured signal With respect to the reconstruction the mea sured magnitude is timing compensated using the timing offset estimated from the measured instantaneous frequency This ensures that the measured magnitude and frequency remain synchronized in the reconstructed waveform A 6 2 Result Summary Evaluations The evaluations for the result summary take place at the sample rate defined by the Display Points Per Symbol parameter see Display Points Sym on page 203 This value can be one of the following e 1 only the symbol instant contributes to the result e 2 two samples per symbol instant contribute to the result required for offset QPSK e the Sample rate defined for data acquisition see Sample Rate page 156 all samples contribute to the result equally The results are determined by the evaluation range The sampling instants at this rate are referred to as t here i e t n Tp where equals the duration of one sampling period at the sample rate defined by the Display Points Per Symbol parameter 6 2 1 Formulae PSK QAM and MSK Modulation For PSK QAM and MSK modulation the estimation model is described in detail in chapter chapter 4 5 1 PSK QAM and MSK Modulation on page 100 The parame ters of the P
431. nd the alignment RST TRIGger Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Reference on page 174 DISPlay WINDow lt n gt TRACe lt t gt X SCALe VOFFset lt VOffset gt This command defines an offset to numbering of the symbols Except capture buffer Setting parameters lt VOffset gt numeric value Range 100000 to 100000 RST 0 Default unit NONE Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Symbol Number at Reference Start on page 175 SENSe DDEMod TIME lt ResultLength gt The command determines the number of displayed symbols result length Setting parameters lt gt numeric value Range 10 to 64000 RST 800 Default unit SYM Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Result Length on page 174 Configuring VSA 11 5 8 Demodulation Settings During demodulation of the vector signal some undesired effects that may occur during transmission can be compensated for Furthermore you can influence the synchroni zation process Manual configuration of the demodulation process is described in chapter 5 9 Demod ulation Settings on page 175 SENSe DDEMod ECALC
432. nes D on dp dB Start 26 sym Stop 174 sym Fig 4 66 Evaluation lines in absolute magnitude diagram In symbol tables the evaluated symbols are indicated by red square brackets D Symbol Table Hexadecimal EMR E sr oec ez er OE os 15 1E 15 0 In other result displays that are based on the evaluation range only two red vertical lines are displayed in the diagram header to indicate a limited evaluation basis Result Summary User Manual 1176 8516 02 06 120 Display Points vs Estimation Points per Symbol 4 7 Display Points vs Estimation Points per Symbol Estimation points per symbol During synchronization the measurement signal is matched to the reference signal and various signal parameters are calculated as well as the optional equalizer You can define how many sample points are used for this calculation at each symbol Typi cally this is one point per symbol symbol rate or a factor of 4 sample rate Display points per symbol The number of points per symbol used for calculation may vary from the number of points used to display the results of the calculation If more points per symbol are selected than the defined sample rate the additional points are interpolated for the dis play The more points are displayed per symbol the more detailed the trace becomes as illustrated in figure 4 67 I Q Vector Mea
433. nfigure the trace to display the average over a series of measurements If necessary increase the Statistics Count defined in the Sweep menu 7 Press the SWEEP key and select the Selected Result Rng softkey to select a specific burst to be evaluated The result displays are updated to show the results for the selected burst Tip You can use a capture buffer display to navigate through the available result ranges and analyze the individual result ranges in another window The currently displayed result range is indicated by a blue bar in the capture buffer display 8 Optionally zoom into a diagram to enlarge an area of the displayed data 9 Optionally change the display scaling for diagrams see chapter 8 3 1 How to Change the Display Scaling on page 223 10 Optionally check the modulation accuracy against specified limits see chap ter 8 3 2 How to Check Limits for Modulation Accuracy on page 225 11 Optionally export the trace data of the measured signal to a file see chapter 8 3 3 How to Export the Trace Data to a File on page 226 R amp S9FPS K70 How to Perform Vector Signal Analysis 8 3 1 8 3 1 1 How to Change the Display Scaling Depending on the type of display time spectrum or statistics various scaling func tions are available to adapt the result display to the current data How to Scale Time and Spectrum Diagrams The range of the displayed y axis for time and spectral diagrams ca
434. ng a low ISI measurment fil ter and the Transmit filter indicated in the title of each diagram Formulae APCO25 CAFM 4 4 20 N N i aaa D 7 1 D D D 1 1 Sm e eq ioo einn m uim mm m quen m mi 1 1 1 D D D D 1 D 1 1 1 D D 1 1 i D 1 D ee 4 e 4 e 1 D 1 D D i 1 i D 1 D D D 1 rr 1 D 1 0 A D i D zi io BELA x 4 4 H D E 1 1 io NC D ta 1 c D D 1 D meme Jae L 4 gt Ve 1 1 i Q 1 D 1 D D 1 D i 1 D o I D i i D D 5 i 1 oz AL e T 2 4 B Rp 4 r i i D D D D D 1 1 1 lt 1 1 D D 2 4 2 4 d D D e i D e 1 1 1 D 1 D 1 D 1 1 1 1 D D M E i D e 1 1 1 D 1 D 1 D D D D L 4 IN IN 4 d 4
435. ngs the ratio of the outer circle radius to the inner circle radius y R2 R1 depends on the utilized code rate and complies with figure 4 41 4 3 11 Symbol Mapping Table 4 15 Optimum constellation radius ratio y linear channel for 16 Code Rate Modulation coding spectral Y efficiency 2 3 2 66 3 15 3 4 2 99 2 85 4 5 3 19 2 75 5 6 3 32 2 70 8 9 3 55 2 60 9 10 3 59 2 57 32APSK For DVB S2 32APSK mappings the ratio of the middle circle radius to the inner circle radius R2 R1 and the ratio of the outer circle radius to the inner circle radius y2 depend on the utilized code rate and comply with table 4 16 Table 4 16 Optimum constellation radius ratios y and linear channel 32APSK Code Rate Modulation coding Y1 spectral efficiency 2 3 3 74 2 84 5 27 3 4 3 99 2 72 4 87 4 5 4 15 2 64 4 64 5 6 4 43 2 54 4 33 8 9 4 49 2 53 4 30 User defined Modulation In addition to the modulation types defined by the standards modulation including symbol mappings can also be defined according to user requirements In this case the mapping is defined and stored in a specific format vam file format and then loa ded to the VSA application Modulation files in vam format can be defined using a mapping wizard mapwiz an auxiliary tool provided by R amp S via Internet free of charge This tool is a precompiled MATLABO file MA
436. nnels in continuous sweep mode INIT CONT ON are repeated RST CONTinuous Example SYST SEQ ON Activates the Sequencer INIT SEQ MODE SING Sets single sequence mode so each active measurement will be performed once INIT SEQ IMM Starts the sequential measurements SYSTem SEQuencer State This command turns the Sequencer on and off The Sequencer must be active before any other Sequencer commands INIT SEQ are executed otherwise an error will occur A detailed programming example is provided in the Operating Modes chapter in the R amp S FPS User Manual Parameters lt State gt OFF 0 1 ON 1 The Sequencer is activated and a sequential measurement is started immediately OFF 0 The Sequencer is deactivated Any running sequential measure ments are stopped Further Sequencer commands INIT SEQ are not available RST 0 11 7 1 Analysis Example SYST SEQ ON Activates the Sequencer INIT SEQ MODE SING Sets single Sequencer mode so each active measurement will be performed once INIT SEQ IMM Starts the sequential measurements SYST SEQ OFF Analysis General result analysis settings concerning the trace markers windows etc can be configured e Configuring Traces entente trn itn entree snnt nn 338 e Working with trn vane et dee Yet a adt e 340 e Configuring Modulation Accuracy Limit 0000 349 e Configuring
437. nt amp Reference Signal oci seis tt iod dietas 15 STO ecd hx rine eer Cent da ue bi M cpu aded o fe otis rx ma ete 16 Error VEGON PH 16 User Manual 1176 8516 02 06 14 R amp S FPS K70 Measurements and Result Displays Modulation SEDES eate tee 16 ACCURACY creto 17 zs lvii P 17 Capture Buffer The captured data In capture buffer result diagrams the result ranges are indicated by green bars along the time axis The currently displayed result range is indicated by a blue bar 3 Mag CaptureBuffer ei CIW 8000 sym Fig 3 1 Result ranges for a burst signal Note You can use the capture buffer display to navigate through the available result ranges using Select Result Rng function and analyze the individual result ranges in separate windows You can change the position of the result range quickly and easily by dragging the blue bar representing the result range to a different position in the capture buffer The default result type is Magnitude Absolute The following result types are available chapter 3 2 21 Magnitude Absolute on page 39 chapter 3 2 22 Magnitude Overview Absolute on page 40 chapter 3 2 28 Real Imag on page 46 chapter 3 2 11 Frequency Absolute on page 29 chapter 3 2 32 Vector I Q on page 53 Remote command LAY
438. ntaneous frequency of zero in the baseband corresponds to the input frequency of the analyzer 2FSK NATURAL With 2FSK the symbol decision is made by a simple frequency discriminator Symbol Numbers Fig 4 23 Constellation diagram for 2FSK NATURAL including the logical symbol mapping 4FSK With the symbol decision is made by a frequency discriminator with 3 decision thresholds 2 3 0 2 3 normalized to the FSK reference deviation Symbol Mapping 1 3 1 3 Fig 4 24 Constellation diagram for 4FSK NATURAL including the logical symbol mapping Symbol Numbers 1 3 1 3 Fig 4 25 Constellation diagram for GRAY including the logical symbol mapping Symbol Numbers x Lue 1 3 Fig 4 26 Constellation diagram for for APCO C4FM and APCO Phase 2 including the logical symbol mapping Symbol Mapping 8FSK NATURAL Symbol Numbers Fig 4 27 Constellation diagram for 8FSK NATURAL including the logical symbol mapping 4 3 7 Minimum Shift Keying MSK MSK modulation causes modulation dependent phase shifts of 90 which be shown in an Constellation diagram As with PSK demodulation is performed by evaluation of the phase positions Table 4 12 MSK NATURAL Logical symbol mapping Modulation symbol binary indication MSB LSB 0 1 Phase shift 90 90 Table 4 13 MSK G
439. nuation hardware is installed on the R amp S FPS you can also activate an electronic attenuator In Auto mode the settings are defined automatically in Manual mode you can define the mechanical and electronic attenuation separately Note Electronic attenuation is not available for stop frequencies or center frequencies in zero span gt 7 GHz In Auto mode RF attenuation is provided by the electronic attenuator as much as possible to reduce the amount of mechanical switching required Mechanical attenua tion may provide a better signal to noise ratio however When you switch off electronic attenuation the RF attenuation is automatically set to the same mode auto manual as the electronic attenuation was set to Thus the RF attenuation may be set to automatic mode and the full attenuation is provided by the mechanical attenuator if possible Both the electronic and the mechanical attenuation can be varied in 1 dB steps Other entries are rounded to the next lower integer value If the defined reference level cannot be set for the given attenuation the reference level is adjusted accordingly and the warning Limit reached is displayed in the status bar Remote command INPut EATT STATe on page 296 INPut EATT AUTO on page 295 INPut EATT on page 295 5 5 4 2 Scaling Depending on the type of display time spectrum or statistics various scaling func tions are available to adapt the result display to the current
440. o also transfer a user receive filter If you upload a customized transmit filter and leave the measurement filter set to auto matic the internally calculated receive filter will be used as measurement filter Note that this filter is not necessarily suitable for your specific signal The filter is optimized such that the intersymbol interference is low Hence you will probably be able to see a clear eye diagram and an Vector diagram with a recognizable constellation How ever a filter that has low intersymbol interference might lead to noise enhancement which is commonly undesirable for a measurement filter In order to avoid noise enhancement it is recommended that you a design your own measurement filter and upload it as a user filter e b select a suitable measurement filter from the list R amp S FPS K70 Measurement Basics Transferring filter files to the R amp S FPS You can transfer the va filter files to the R amp S FPS using a USB memory device 4 2 Sample Rate Symbol Rate and Bandwidth The Symbol Rate defined in the Signal Description settings determines how many symbols are captured and demodulated during a certain measurement time However for each symbol more than one sample may be captured so that the sample rate may be higher than the symbol rate The Sample Rate parameter in the Data Acquisition settings defines the number of samples to capture per symbol not to be confused with t
441. o the Known Data may increase the measure ment duration as each detected symbol must be compared to each possible sequence in the data file Result Length The Result Length specified in the Result Range dialog box in the VSA application must be identical to the length of the specified symbol sequences in the xml file lt ResultLength gt element Result Range Alignment Bursted signals When you align the result range to a bursted signal due to the uncertainty of the burst search the determined result range might start up to 2 symbols before or after the actual burst However an offset of only one symbol has the effect that none of the predefined symbol sequences in the Known Data file will be found To avoid this try one of the following Align the result range to a pattern instead of the burst Use a precise external trigger and align the result range to the capture buffer This requires a very precise trigger timing otherwise the result range start may be incorrect again Continuous signals For continuous signals without a pattern the result range is aligned randomly Thus a very large number of possible sequences must be predefined Use precise external trigger and align the result range to the capture buffer This requires a very precise trigger timing otherwise the result range start may be incor rect again 4 10 VSA in MSRA Operating Mode The R amp S FPS VSA application can also be used to analyze
442. od against the component in the time domain The symbol time instants of the and the Q component therefore do not coincide The offset EVM controls the calculation of all results that are based on the error vector It affects the EVM Real Imag and Vector I Q result displays as well as the EVM results in the Result Summary EVM and MER You can configure the way the VSA application calculates the error vector results If Offset EVM is disabled the VSA application substracts the measured signal from the reference signal to calculate the error vector This method results in the fact that the error vector contains two symbol instants per symbol period one that corresponds to the component and one that corresponds to the Q component If Offset EVM is enabled however the VSA application compensates the delay of the Q component with respect to the component in the measurement signal as well as the reference signal before calculating the error vector That means that the error vector contains only one symbol instant per symbol period Remote command SENSe DDEMod ECALc OFFSet on 319 R amp S FPS K70 Configuration 5 10 Measurement Filter Settings The measurement filter can be used to filter both the measured signal and the refer ence signal and thus the error vector You can configure the measurement filter to be used For more information on measurement filters see chapter 4 1 4 Measurement
443. odulated difference between the complex measurement signal and the complex reference signal Modulation measurement signal reference signal For example EVM Mag meas ref The default result type is EVM The following result types are available chapter 3 2 7 Error Vector Magnitude on page 26 e chapter 3 2 28 on page 46 chapter 3 2 32 Vector on page 53 Remote command LAY ADD 1 BEL EVEC see LAYout ADD WINDow on page 359 Modulation Errors The difference between the modulated complex samples in the measurement and the modulated reference signal Modulation measurement signal Modulation reference signal For example Magnitude Error Mag meas Mag ref The default result type is Magnitude Error The following result types are available chapter 3 2 21 Magnitude Absolute on page 39 chapter 3 2 25 Phase Error on page 43 chapter 3 2 13 Frequency Error Absolute on page 32 chapter 3 2 14 Frequency Error Relative on page 33 Remote command LAY ADD 1 BEL MERR see LAYout ADD WINDow on page 359 R amp S9FPS K70 Measurements and Result Displays _ lt ___________________________________________________________________________________________ ____ Modulation Accuracy Paraeters that characterize the accuracy of modulation The default result type is Result Summary The following res
444. of the zoom windows all subsequent zoom windows move up one position Parameters State OFF RST OFF Manual operation See Multiple Zoom on 205 See Restore Original Display on page 205 See Deactivating Zoom Selection mode on page 205 Configuring the Result Display The following commands are required to configure the result display in a remote envi ronment The tasks for manual operation are described in chapter 6 5 Display and Window Configuration on page 201 User Manual 1176 8516 02 06 357 11 8 1 Configuring the Result Display e General Window Gommalids eret odere eene tener 358 e Working with Windows in the Display enne 359 VSA Window Configuration sess 364 General Window Commands The following commands are required to configure general window layout independent of the application Note that the suffix n always refers to the window in the currently selected measure ment channel see INSTrument SELect on page 272 POR ette 358 DISPlay EWINDOWSN gt SIZE rd reete trei ral re t hae nr 358 DISPlay FORMat Format This command determines which tab is displayed Parameters Format SPLit Displays the MultiView tab with an overview of all active chan nels SINGIe Displays the measurement channel that was previously focused RST SING Ex
445. offset after demodulation and error compensation The effect of an offset in the transmitter is shown in figure 4 54 The offset can be compensated for if the corresponding option is selected in the demodulation settings In this case the offset does not affect the EVM R amp S FPS K70 Measurement Basics Example The following figures compare the results for a compensated l Q offset of 2 5 and non compensated offset Offset compensated for Offset NOT compensated for 170 Const Meas amp Ref 1M Clrw 170 Const Meas amp Ref 1M Clrw Stop 2 52 1 Clrw Stop 2 52 Start 0 sym Stop 300 sym Start 0 sym Stop 300 sym Gain Imbalance Quadrature 1 0 5 0 25 1 Inphase Fig 4 55 Effect of gain imbalance The gain difference in the and Q channels during signal generation in the transmitter is referred to as gain imbalance The effect of this error on the constellation diagram and the unit circle are shown in figure 4 55 In the example the gain in the channel is slightly reduced which causes a distortion of coordinates in the direction The unit cir cle of the ideal constellation points has an elliptic shape User Manual 1176 8516 02 06 105 Signal Model Estimation and Modulation Errors The gain imbalance can be compensated for if the corresponding option is selected in the demodulation settings In this case the imbalance does
446. oh 1 ene does STAT s QUEStionable SYNG EVENI iint ntpote te tate ner o HER Lee EPA De XE REREPEN EE 400 SYSTem PRESetCHANhnel EXEQGUte citer rrt rr n er ni rne rn merae cadens eas 273 5 CATENE NAVES E DENA LA TOV EVSA ATRAENTE NENTE Rd ESAE 337 TRANG SiC 303 TRAGesns ttre ct reve dud 374 TRIGger SEQuence D Mensis rt rrr ere ren rere n e Fra tr iocari e aeris 304 HOLDO TIME aia centi troie ttn hi tt eoe is Ret REIS 304 TRIGgerl SEQuence cct trt tette ete etre th ttr e cse 304 TRIGger SEQuence lIEPower HYSTeresls nie rie rr te ntt te rrr er detinet 304 pRIGger SEQuericelEEVelTEPOWOE ccce ctore eene eror rr ede TEETE E ENE 305 SEQUENCE EEVSEIQPOWOF ei e ceteri ta eee act dete cete etel 305 TRIGger SEQuence LEVel EXTerral port 2 1 rot tr rette rer the erri 305 TRIGger SEQuence SLOPe SEQUENCE SOURCe rrr err nee rente ine e RR I cen PNE S Index Symbols 4ASK Constellation diagram ues ccc trn there eei 85 8PSK Constellation diagram ccc tn rrt 70 16APSK Constellation diagram zc cct bene cs 86 95 ile FORMU A we 430 A
447. oint as decimal separator e g 4 05 RST RST has no effect on the decimal separator Default is POINt Example FORM DEXP DSEP POIN Sets the decimal point as separator Manual operation See Decimal Separator on page 194 FORMat DEXPort HEADer lt Header gt This command defines if a file header including start frequency sweep time detector etc is created or not A small header with the instrument model the version and the date is always transferred Setting parameters lt Header gt ON OFF 1 0 RST 0 Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Header on page 193 FORMat DEXPort MODE lt Mode gt This command defines which data are transferred raw data or trace data Setting parameters lt Mode gt RAW TRACe RST TRACe Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Data Export Mode on page 193 MMEMory STORe lt n gt TRACe lt Trace gt lt FileName gt This command exports trace data from the specified window to an ASCII file Secure User Mode Retrieving Results In secure user mode settings that are to be stored on the instrument are stored to vol atile memory which is restricted to 256 MB Thus a Memory full error may occur although the hard disk indicates that stora
448. ollowing files parameter XML file e g 2 1 Contains meta information about the data e g sample rate The filename can be defined freely but there must be only one single parameter XML file inside an iq tar file data binary file e g xyz complex float32 Contains the binary data of all channels There must be only one single data binary file inside an iq tar file Optionally an iq tar file can contain the following file preview XSLT file e g open IqTar xml file in web browser xslt Contains a stylesheet to display the parameter XML file and a preview of the data in a web browser A sample stylesheet is available at htto www rohde schwarz com file open IqTar xml file in web browser xslt 7 1 I Q Parameter XML File Specification RsIqTar xsd available at http www rohde schwarz com file RslqTar xsd CD The content of the parameter XML file must comply with the XML schema In particular the order of the XML elements must be respected i e iq tar uses an ordered XML schema For your own implementation of the iq tar file format make sure to validate your XML file against the given schema The following example shows an parameter XML file The XML elements and attrib utes are explained in the following sections Sample parameter XML file xyz xml lt xml version 1 0 encoding UTF 8 g xml stylesheet type text xsl href open
449. olumn of the Result Summary In this case you can use the capture buffer display to navigate through the available result ranges Select Result Rng function and analyze the indi vidual result ranges in separate windows The currently displayed result range is indi cated by a blue bar in the capture buffer display You can change the position of the result range quickly and easily by dragging the blue bar representing the result range to a different position in the capture buffer Continuous and discrete result ranges Depending on the type of signal and your result range definition the result ranges may be continuous or discrete Bursted signals commonly have several discrete result ranges at the bursts with intervals during the noise periods which should not be inclu ded in the results see figure 4 64 Continuous signals on the other hand have result ranges that cover the entire or a specific part of the capture buffer without intervals C Mag CapBuf A CUBA 40 dBm 60 dBm 80 dBm Fig 4 65 Result ranges for a continuous signal Result Range Length The result range length is defined by the number of symbols that are to be demodula ted All traces over time are displayed over the result range For example if you have a User Manual 1176 8516 02 06 118 4 6 2 Measurement Ranges burst of 100 symbols and you define the result length as 200 symbols you can exam ine the burst
450. on Convention Description Graphical user interface ele All names of graphical user interface elements on the screen such as ments dialog boxes menus options buttons and softkeys are enclosed by quotation marks KEYS Key names are written in capital letters File names commands File names commands coding samples and screen output are distin program code guished by their font Input Input to be entered by the user is displayed in italics Links Links that you can click are displayed in blue font References References to other parts of the documentation are enclosed by quota tion marks Starting the VSA Application 2 Welcome to the Vector Signal Analysis Application The R amp S FPS K70 is a firmware application that adds functionality to perform Vector Signal Analysis VSA to the R amp S FPS The R amp S FPS VSA application performs vector and scalar measurements on digitally modulated single carrier signals To perform the measurements it converts RF signals into the complex baseband Use of an optional external mixer is also supported The R amp S FPS VSA application features e Flexible modulation analysis from MSK to 10240 Numerous standard specific default settings Various graphical numerical and statistical evaluations and result displays e Spectrum analyses of the measurement and error signal Flexible burst search for the analysis of complex signal combinations
451. on Overview Throughout the measurement channel configuration an overview of the most important currently defined settings is provided in the Overview Overview The Overview is displayed when you select the Overview icon which is available at the bottom of all softkey menus Overview Std A SR 384 MRe Vector Signal Analysis Modulation Input Capture Length Symbol Rate Center Freq Sample Rate Tx Filter Ref Level Trigger Mode Signal Type A Trigger Offset Input Frontend Signal Capture Result Length Alignment Cut Result Ranges Start Stop Display Config Lu Specific Settings for In addition to the main measurement settings the Overview provides quick access to the main settings dialog boxes The individual configuration steps are displayed in the order of the data flow Thus you can easily configure an entire measurement channel from input over processing to output and analysis by stepping through the dialog boxes as indicated in the Overview In particular the Overview provides quick access to the following configuration dialog boxes listed in the recommended order of processing 1 Signal Description See chapter 5 4 Signal Description on page 134 Input and Frontend Settings See chapter 5 5 Input Output and Frontend Settings on page 142 Signal Capture including Triggering See chapter 5 6 Signal Capture on page 154 Burst Pattern Configurat
452. on normalized to the mean expected power of the mea surement signal at the symbol instants MACPower Calculation normalized to the maximum expected power of the measurement signal at the symbol instants RST SIGNal See Normalize EVM to on page 181 SENSe DDEMod ECALc OFFSet lt EVMOffsetState gt ConfigureS the way the VSA application calculates the error vector results for offset QPSK Setting parameters lt EVMOffsetState gt Manual operation ON OFF 1 0 ON VSA application compensates the delay of the Q component with respect to the component in the measurement signal as well as the reference signal before calculating the error vector That means that the error vector contains only one symbol instant per symbol period OFF the VSA application substracts the measured signal from the ref erence signal to calculate the error vector This method results in the fact that the error vector contains two symbol instants per symbol period one that corresponds to the component and one that corresponds to the Q component RST 1 See Offset EVM on page 184 SENSe DDEMod EPRate AUTO lt LinkMode gt Defines how many sample points are used at each symbol to calculate modulation accuracy results automatically If enabled the VSA application uses the following settings depending on the modula tion type Configuring VSA Modulation Est Points PSK QAM 1 Offset QPSK 2 FSK MSK Sample r
453. on see Statistic Count on page 162 11 5 6 11 5 6 1 Configuring VSA Setting parameters lt SweepCount gt numeric value 0 activates Auto mode numeric value gt 0 Activates Manual mode and sets the statistics count to the cor responding number Range 0 to 200000 RST 0 Default unit NONE Usage SCPI confirmed Manual operation See Statistic Count on page 162 SENSe SWEep COUNt CURRent lt Counter gt This command queries the current statistics counter value which indicates how many result ranges have been evaluated For results that use the capture buffer as a source the number of used capture buffers can be queried Setting parameters lt Counter gt CAPTure STATistics STATistics Returns the number of result ranges that have been evaluated CAPTure Returns the number of used capture buffers evaluated RST STATistics Configuring Bursts and Patterns The burst and pattern search settings can be configured and new patterns can be defined Manual configuration of bursts and patterns is described in chapter 5 7 Burst and Pat tern Configuration on page 164 BUSCO CARCI 308 e Pattern 1 310 Goftfiguring e lebe d 312 Burst Search The burst search commands define when a burst is detected in the analyzed signal
454. or not the analysis line lies within the analysis interval or not orange AL the line lies within the interval white AL the line lies within the interval but is not displayed hidden the line lies outside the interval VSA in MSRA Operating Mode DECT P32 SR 1 152 MHz Att 1048 Freq 1325 GHz Len YIG Bypass BURST PATTERN 1 Freq Error Rel Analysis Interval 230 902778 us 616 319444 us Pn P 1 TRE id LM A sym 12 sym 3 Mag CaptureBuffer Date 15 0CT 2012 16140129 For details on the MSRA operating mode see the R amp S FPS MSRA User Manual 9 Configuration Using the VSA application you can perform vector signal analysis measurements using predefined standard setting files or independently of digital standards using user defined measurement settings Such settings can be stored for recurrent use Thus configuring measurements requires one of the following tasks e Selecting an existing standard settings file and if necessary adapting the mea surement settings to your specific requirements e Configuring the measurement settings and if necessary storing the settings in a file VSA application When you switch the application of a measurement channel to VSA the first time a set of parameters is passed on from the currently active application
455. ormation on the expected input signal which optimi zes pattern and burst detection and the calculation of the ideal reference signal Manual configuration of the signal description is described in chapter 5 4 Signal Description on page 134 et 276 284 Modulation The modulation settings vary depending on the selected modulation type in particular FSK modulation provides some additional settings lt gt 276 CALCulate lt n gt FSK DEViation REFerence VALUE 2 277 SENSe DDEMGG APSKINS Mates PR tene nant enira E eonun pn mien rep 277 SENSe TDDEMOdASINS Eagle eere ene bcne eases 277 I SENSe IDDEModFIETer AIPH 277 SENSe DDEMod FILTer STATe ecce 278 ntc en ute a bo ee uer ree ei 278 SENSe IDBEMod FSK NS Tale 12 repose eo HIE 5658 279 SENSe DDEMod MAPPing CATalog annt rne eer dne e x age bn 279 SENSe DDEMod MAPPing VALue eene reri h rnnt nn ns 279 I SENSe gDDEMod MSNK FORIMal cited eraat creta 280 SENSe ID
456. ormulae Test parameter Formula Frequency l d FREQ ug sf wg M 14 FREQprr Magnitude error MAG _ ERR t MAG yas MAG pur Phase error PHASE _ ERR t PHASE ypas t PHASE pep t FREO ERR FREQ uras FSK Modulation The trace based results for FSK signals are the same as those available for linear modulation types However as the signal processing for FSK signals is performed on the magnitude and instantaneous frequency the based results first require a recon struction of the reference and measured waveforms as illustrated Reconstruc tion of the reference and measured waveforms for FSK modulation The dashed outline of the compensate blocks indicate that these operations are optionally de activated depending on the corresponding user settings With respect to FSK measurements the optional compensation parameters are FSK Reference deviation Carrier frequency drift Formulae Figure 3 Compensate Reference deviation Frequency frer n ee Compensate Frequency Reference Ref deviation Modulator Measured Frequency fugas Q1 P Compensate Frequency Measured iming EE Carrier drift Modulator Carrier offset i Compensate Auras Timing Gain Fig 1 1 Reconstruction of the reference and measured waveforms for FSK modulation Note that a refere
457. osed to INI Tiate lt n gt IMMediate this command does not reset traces in maxhold minhold or average mode Therefore it can be used to continue measure ments using maxhold or averaging functions Suffix lt n gt irrelevant Usage Event Manual operation See Continue Single Sweep on page 162 INITiate lt n gt CONTinuous lt State gt This command controls the measurement mode for an individual measurement chan nel Note that in single measurement mode you can synchronize to the end of the mea surement with OPC OPC or WAI In continuous measurement mode synchroniza tion to the end of the measurement is not possible Thus it is not recommended that you use continuous measurement mode in remote control as results like trace data or markers are only valid after a single measurement end synchronization For details on synchronization see the Remote Basics chapter in the R amp S FPS User Manual Performing a Measurement If the measurement mode is changed for a measurement channel while the Sequencer is active see INITiate lt n gt SEQuencer IMMediate page 336 the mode is only considered the next time the measurement in that channel is activated by the Sequencer Suffix n irrelevant Parameters State OFF 0 1 ON 1 Continuous measurement OFF 0 Single measurement RST 0 Example INIT CONT OFF Switches the measurement mode to single measurement INIT CONT ON Switches the measur
458. osition of the splitter as a fraction of the screen area without channel and status bar and softkey menu The point of origin x 0 y 0 is in the lower left corner of the screen The end point x 100 y 100 is in the upper right cor ner of the screen See figure 11 1 The direction in which the splitter is moved depends on the screen layout If the windows are positioned horizontally the splitter also moves horizontally If the windows are positioned vertically the splitter also moves vertically Range 0 to 100 Example LAY SPL 1 3 50 Moves the splitter between window 1 Frequency Sweep and 3 Marker Table to the center 50 of the screen i e in the fig ure above to the left User Manual 1176 8516 02 06 362 Configuring the Result Display Example LAY SPL 1 4 70 Moves the splitter between window 1 Frequency Sweep 3 Marker Peak List towards the top 70 of the screen The following commands have the exact same effect as any combination of windows above and below the splitter moves the splitter vertically AY SPL 3 2 70 AY SPL 4 1 70 AY SPL 2 1 70 LAYout WINDow n ADD lt Direction gt lt WindowType gt This command adds a measurement window to the display Note that with this com mand the suffix n determines the existing window next to which the new window is added as opposed to LAYout ADD WINDow 2 for which the existing window is define
459. ot used 5 Error in current peak value 6 Error in mean peak value 7 Error in peak peak value 8 15 These bits are not used 11 11 4 STATus QUESTionable MODulation lt n gt PHASe Register This register comprises information about limit violations in Phase Error evaluation It can be queried with commands STATus QUEStionable MODulation lt n gt PHASe CONDition and STATus QUEStionable MODulation lt n gt PHASe EVENt Bit No Meaning 0 Error in current RMS value 1 Error in mean RMS value 2 Error in peak RMS value 3 4 These bits are not used 5 Error in current peak value 6 Error in mean peak value 7 Error in peak peak value 8 15 These bits are not used 11 11 5 STATus QUESTionable MODulation lt n gt MAGnitude Register This register comprises information about limit violations in Magnitude Error evaluation It can be queried with commands STATus QUEStionable MODulation lt n gt MAGNitude CONDition and STATus QUEStionable MODulation lt n gt MAGNitude EVENt Status Reporting System Bit No Meaning 0 Error in current RMS value 1 Error in mean RMS value 2 Error in peak RMS value 3 4 These bits are not used 5 Error in current peak value 6 Error in mean peak value 7 Error in peak peak value 8 15 These bits are not used 11 11 6 STATus QUESTionable MODulation lt n gt CFRequency Register This register compris
460. ou can select a different evaluation method result type for the window based on the data source selected in the Dis play Configuration Display and Window Configuration 6 5 1 Window Configuration For each window you can select a different evaluation method result type based on the data source selected in the Display Configuration Further window settings are available for some result types The Window Configuration is displayed when you select the Window Config softkey from the main VSA menu Some settings are only displayed after you select the More button in the dialog box To hide these settings select the Less button ers EM 202 TYG R 202 Result Type Transformatiorm eir t een e erede eed 11215 202 EC 203 Display 203 203 Signal Source Data source as selected in the Display Configuration see chapter 3 Measurements and Result Displays on page 14 If you change the signal source setting here the default result type for the new data source is activated for the current window Remote command LAYout ADD WINDow on page 359 Result Type The result type defines the evaluation method used in the current window The available result ty
461. ount see Statistic count ipe Symbol check e 96 Demodulation 2 ttt een torrenti 96 PAWE S ESTE 96 Symbol decisions eea Demodulation Demodulation process Known data Symbol error rate SER Fine synchronization siisii ter erts 184 Symbol MAPPING 67 137 ii ee ead 86 ASK scutis 2 85 Differential PSK ned FSK contes ird mi Offset QPSK was FO OOK qe 85 aaa 68 QAM etd 2 80 Rotating differentialPSK Rotating PSK 571 User defined 207 Wizard pent rrr trea nein tte 87 Symbol number Res lt range start eter 175 Symbol rate 121 137 BASICS m 56 Display 12 124 Relationship to sample rate 64 Remote des Symbol Rate EMOT 178 Symbol Rate Error SRE Definition herren 103 Symbol tables 51 Symbols Data SOUFCE 16 Format patterns eoe 173 eer nore reet trente 203 Patterns a 173 FRESUIE types et memet nnns 16 Window Configuration
462. ous Sweep 0 25 0 67 29 deg Continue 1 Select Result Range eg 9 X Carrier Freq Error Sweep Imbalance k L Quadrature Error 4 Amplitude Droop VR i ias ATA Wr iP S Start 0 sym Stop 148 sym Mag CapBuf 1 Statistic Count Auta Select Result Rng 2 cem Start 0 sym Stop 10000 sym Fig 9 8 Navigation through the capture buffer 9 3 4 Evaluating the Rising and Falling Edges The Result Length is the number of symbols that are to be demodulated and ana lyzed together In most common applications only the parts of the capture buffer con taining the bursts need to be analyzed Hence for bursted signals the Result Length usually coincides with the burst length However there are certain scenarios where the rising and falling edge of a burst are also of interest e g checking the power ramping of the device under test For this measurement task it is useful to choose a Result Length that exceeds the burst length 1 In order to include the rising and falling edges of the bursts in the EVM vs Time display window 1 you need to increase the Result Length In the Overview select Cut Result Range and increase the Result Length to 200 symbols 2 To evaluate the rising and falling edges further display the absolute magnitude val ues of the measured signal in window 4 Source Meas amp Ref Signal Result type Magnitude Absolut
463. own data failed otherwise 1 Usage Query only Manual operation See Fine Synchronization on page 183 SENSe DDEMod FSYNc MODE lt FineSync gt This command defines the fine synchronization mode used to calculate results e g the bit error rate Note You can define a maximum symbol error rate SER for the known data in refer ence to the analyzed data If the SER of the known data exceeds this limit the default synchronization using the detected data is performed See SENSe DDEMod FSYNc LEVel on page 322 Setting parameters lt FineSync gt KDATa PATTern DDATa KDATa The reference signal is defined as the data sequence from the loaded Known Data file that most closely matches the measured data PATTern The reference signal is estimated from the defined pattern This setting requires an activated pattern search see SENSe DDEMod SEARch SYNC STATe on page 312 DDATa Default The reference signal is estimated from the detected data RST DDATa Manual operation See Fine Synchronization on page 183 SENSe DDEMod KDATa STATe lt KnownDataState gt This command selects the Known Data state The use of known data is a prerequisite for the BER measurement and can also be used for the fine sync Configuring VSA Setting parameters lt KnownDataState gt OFF 1 0 RST 0 Manual operation See Known Data on page 142 SENSe DDEMod KDATa NAME lt FileName gt This command selects t
464. pe SCPI Parameter Source Vector COMP Modulation Errors Magnitude Error MAGNItude Phase Error PHASe Frequency Error Absolute FREQuency Frequency Error Relative FREQuency Modulation Accuracy Bit Error Rate BERate Result Summary RSUM Equalizer Impulse Response Magnitude MAGNItude Impulse Response Phase UPHase Impulse Response Real Image RIMag Frequency Response Magnitude MAGNItude Frequency Response Phase UPHase Frequency Response Group Delay GDELay Channel Frquency Response Magni MAGNitude tude Channel Frequency Response Group GDELay Delay Multi Source Spectrum Real Imag Capture buffer RIMag query only Error Spectrum Real Imag Measurement RIMag query only Error For details on selecting the data source and result types for evaluation see chapter 6 5 Display and Window Configuration on page 201 Remote command CALCulate lt n gt FORMat on page 366 e Bit Error Rate BER etcetera pe PR e hs 20 e Channel Frequency Response Group 22 e Channel Frequency Response Magnitude eese 22 e Constellation Fregueriy e uice ect tec v aee e xen du 23 e Coristellatigm VO iiit 24 e Constellation 25 e JEitorVvectorMagnibude EVM p dace tte ueris 26 Eye Diagram Frequenty 27 e Eye Diagram mag
465. pes in VSA are described in chapter 3 2 Result Types in VSA on page 18 Remote command CALCulate lt n gt FORMat on page 366 Result Type Transformation For certain result types it is not only possible to see the common over time represen tation of the measurement but also the spectrum or the statistics in form of a histo gram These are the transformations of the results These settings are not available for symbol evaluation i e the following signal sources Symbols Modulation Accuracy Normal Evaluation in time domain X axis displays time values Spectrum Evaluation in frequency domain X axis displays frequency values The usable bandwidth is indica ted in the display Display and Window Configuration Statistics Statistical evaluation histogram X axis displays former y values Y axis displays statistical informa tion Trace 1 the probability of occurrence of a certain value is plotted against the value e Trace 2 the cumulated probability of occurance is plotted against the value Remote command CALCulate lt n gt DDEM SPECtrum STATe on page 365 CALCulate lt n gt STATistics CCDF STATe on page 368 Highlight Symbols If enabled the symbol instants are highlighted as squares in the window for measured and reference signals in time normal display as well as error displays Only evaluations that are based on symbols e g constellations or traces support this function R
466. pitalization 266 Character data 2 Data blocks 269 Numeric values 267 Optional keywords Parameters Strings 269 M 266 Resetting RF inputptot ction gt rernm 288 Restoring Channel settings 133 Factory settings 129 Patt rtifiles eit erret rrt es 129 Standardifil s retos 129 131 Result display Configuration remote Troubleshooting enters Result displays SOUIGBS ente ene prepaid 14 Result length 2 118 DEDE 12 Known data 124 QAM modulation 80 RANGES 2 52 174 Result range AGED ooi eti ea 119 175 Alignment known data 124 Configuration a 173 Defining 220 DEFINITION 44117 Demodulation process oiiaii 89 Display Evaluating Length sur p Overlapping 2 metere 255 Reference 174 Remote 5915 Run In out 5119 Selecting einer eee 163 Result Summary Configuration 50 Display points per symbol 121 Evaluations Em
467. play points per symbol parameter see Display Points Sym on page 203 are drawn and connected Available for source types e amp Ref Signal EM User Manual 1176 8516 02 06 52 R amp S9FPS K70 Measurements and Result Displays 3 2 32 Vector Freq Meas amp Ref 1M Cinw Fig 3 23 Result display for Vector Frequency Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM COVF to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 3 Polar Diagrams on page 376 Vector The complex source signal as an X Y plot all available samples as defined by the dis play points per symbol parameter see Display Points Sym on page 203 are drawn and connected The scaling of the capture buffer depends on the input source e Scaling is relative to the current reference level for RF input e Scaling is relative to the full scale level for I Q input Available for source types e Capture Buffer e Meas amp Ref Signal Error Vector Capture buffer display Note that this result display is based on an individual capture buffer range If more than 256 000 samples are captured overlapping ranges with a size of 256 000 each are created Only one range at a time can be displayed in the Vec
468. plays 3 2 10 Eye Diagram I 3 2 11 The eye pattern of the inphase 1 channel the x axis value range is from 1 to 1 sym bols MSK 2 to 2 Available for source types e Meas amp Ref Signal 1 Eye I Meas amp Ref Fig 3 7 Result display Eye Diagram Real I Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM IEYE to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 Frequency Absolute The instantaneous frequency of the signal source the absolute value is displayed in Hz Available for source types e Meas amp Ref Signal e Capture Buffer uum EIN NDA CN V NUUS User Manual 1176 8516 02 06 29 R amp S FPS K70 Measurements and Result Displays emm M P EEUU AUREUM ee aes Meas amp Ref signal FREQ uas e ZMEASQ 2 z dt with and duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 Capture buffer l d FREQ crr r Som di ZCapt t When evaluating the capture buffer the absolute frequency is derived from the mea sured phase with duration of one
469. pter 9 2 3 Changing the Display Configuration on page 232 A clear 8PSK constellation is displayed Const I Q Meas amp Ref 1M Clew D MagAbs MeastRef Stop 2 535 Start 26 sym Stop 174 sym Fig 9 10 Evaluation lines properly adjusted User Manual 1176 8516 02 06 241 R amp S FPS K70 Measurement Examples In order to understand the effect of an incorrectly set evaluation range change the evaluation range to include the entire result range a Inthe Overview select Evaluation Range b Enable the Entire Result Range option The displayed constellation diagram is no longer clear it contains additional points This is due to the fact that the constellation diagram now displays symbol instants that are beyond the burst Const I Q MeasRRof 1M Cirw MagAbs Meas amp Ref Stop 174 sym Fig 9 11 Evaluation lines not properly adjusted small red lines in the title bar o All measurement windows that consider the evaluation range are marked with two A Const I Q Meas amp Ref 1M Clrw 9 3 6 Comparing the Measurement Signal to the Reference Signal You have seen that it is possible to add different traces such as maximum hold or aver age to each window When evaluating the measurement signal it is also possible to display the ideal reference signal as an additional trace This can be a significant help when troubleshooting since it allows for an immediate comparison 1 Je Sta
470. quence The l Q pattern is then correlated with the measured signal User Manual 1176 8516 02 06 252 R amp S FPS K70 Optimizing and Troubleshooting the Measurement At positions where the correlation metric exceeds the I Q Correlation Threshold the pattern is found Stage 2 demodulates the measured signal at the pattern location and the trans mitted symbols are checked for correctness against the pattern symbol sequence In case of a very short pattern i e a pattern length in the order of the inter symbol interference ISI duration a number of issues can arise False positive The pattern is found at positions where the transmitted symbols differ from the pattern symbols Solution Try one of the following Activate Meas only if Pattern Symbols Correct Increase the Correlation Threshold see chapter 5 7 2 Pattern Search on page 166 False negative The pattern search misses a position where transmitted symbols match the pat tern symbols Solution Decrease the I Q Correlation Threshold see chapter 5 7 2 Pattern Search on page 166 In case of bursted signals the pattern search finds only the first occurrence of the pattern within each burst If a false positive occurs in this situation cf case 1 the use of Meas only if pattern symbols correct will not provide a satisfactory sol ution In this case do the following increase the Correlation Thr
471. quency Error RMS value 1 Error in mean Frequency Error RMS value 2 Error in peak Frequency Error RMS value 3 4 These bits are not used 5 Error in current Frequency Error peak value 6 Error in mean Frequency Error peak value 7 Error in peak Frequency Error peak value 8 9 These bits are not used 10 Error in current Frequency Deviation value 11 Error in mean Frequency Deviation value 12 Error in peak Frequency Deviation value 13 15 These bits are not used 11 11 9 Querying the Status Registers The following commands query the contents of the individual status registers 5 5 1 399 STATus QUESHonable DIQ CONDIBOR pna uae cena 399 STATus QUEStionable FREQuency CONDiition aecsiiisesieisee aenean 399 lt gt 399 lt gt 399 5 5 lt gt eese 399 lt gt 399 lt gt
472. r FSK deviation erroris the difference of the FSK deviation of the measured signal and the FSK referencedeviation you have set FSK Meas Deviation The estimated deviation of FSK modulated signals in Hz FSK MDEViation FSK Ref Deviation The reference deviation you have set in Hz FSK RDEViation Carrier Frequency Drift The mean carrier frequency drift in Hz per symbol FSK CFDRift Remote command CALCulate lt n gt MARKer lt m gt FUNCtion DDI EMod STATistic Parameter Filters and Bandwidths During Signal Processing 4 Measurement Basics Some background knowledge on basic terms and principles used in VSA is provided here for a better understanding of the required configuration settings For information on the basic processing of data in the R amp S FPS see the R amp S FPS Analyzer User Manual 4 1 Filters and Bandwidths During Signal 56 Sample Rate Symbol Rate and 63 Symbol MAPPING e 67 Overview of the Demodulation 88 Signal Model Estimation and Modulation 100 Measurement Ranges eerte eremi cta pee ee ce 116 Display Points vs Estimation
473. r type This command queries the results of the frequency error of FSK modulated signals Query parameters type Usage Retrieving Results lt none gt RMS frequency error of display points of current sweep AVG Average of RMS frequency errors over several sweeps PAVG Average of maximum frequency errors over several sweeps PCTL 95 percentile of RMS frequency error over several sweeps PEAK Maximum EVM over all symbols of current sweep PPCT 95 percentile of maximum frequency errors over several sweeps PSD Standard deviation of maximum frequency errors over several sweeps RPE Maximum value of RMS EVM over several sweeps SDEV Standard deviation of frequency errors over several sweeps TPE Maximum EVM over all display points over several sweeps Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic FSK MDEViation lt type gt This command queries the results of the measurement deviation of FSK modulated signals Query parameters lt type gt Usage lt none gt Measurement deviation for current sweep AVG Average FSK measurement deviation over several sweeps RPE Peak FSK measurement deviation over several sweeps SDEV Standard deviation of FSK measurement deviation PCTL 95 percentile value of FSK measurement deviation Query only Retrieving Results CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic FSK RDEViation lt type gt This co
474. r the last header element even if the command contains a parameter A header contains one or more keywords separated by a colon Header and parame ters are separated by a white space ASCII code 0 to 9 11 to 32 decimal e g blank Introduction If there is more than one parameter for a command these are separated by a comma from one another Only the most important characteristics that you need to know when working with SCPI commands are described here For a more complete description refer to the User Manual of the R amp S FPS Remote command examples Note that some remote command examples mentioned in this general introduction may not be supported by this particular application 11 1 1 Conventions used in Descriptions Note the following conventions used in the remote command descriptions Command usage If not specified otherwise commands can be used both for setting and for querying parameters If a command can be used for setting or querying only or if it initiates an event the usage is stated explicitely Parameter usage If not specified otherwise a parameter can be used to set a value and it is the result of a query Parameters required only for setting are indicated as Setting parameters Parameters required only to refine a query are indicated as Query parameters Parameters that are only returned as the result of a query are indicated as Return values e Conformity Commands that are taken from the SC
475. r 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Manual operation See Transmit Filter Type on page 138 See Load User Filter on page 138 SENSe DDEMod TFILter STATe lt TXFilterState gt Use this command to switch the transmit filter off To switch a transmit filter on use the SENSe DDEMod TFILter NAME command 11 5 1 2 Configuring VSA Setting parameters lt TXFilterState gt ON OFF 1 0 OFF Switches the transmit filter off ON Switches the transmit filter specified by SENSe DDEMod TFILter NAME on However this command is not necessary as the SENSe DDEMod TFILter NAME command automati cally switches the filter on RST 1 Manual operation See Transmit Filter Type on page 138 SENSe DDEMod TFILter USER lt FilterName gt This command selects a user defined transmit filter file Setting parameters lt FilterName gt The name of the transmit filter file Manual operation See Transmit Filter Type on page 138 See Load User Filter on page 138 SENSe DDEMod USER NAME lt Name gt Selects the file that contains the user defined modulation to be loaded Setting parameters lt Name gt string Path and file name of the vam file Example SENS DDEM FORM UQAM Define the use of a user defined modulation SENS DDEM USER NAME D MyModulation vam Select the file name to be loaded
476. r details see chapter 11 9 2 Measurement Results for TRACe lt n gt DATA TRACE lt n gt on page 375 Setting parameters Trace TRACe1 TRACe2 TRACe3 TRACe4 5 TRACe6 TRACe1R 1 TRACe2R TRACe21 TRACe3R TRACe3l TRACe1 2 3 4 5 6 The complete data from the corresponding trace TRACe1R TRACe2R TRACe3R The real data from the corresponding trace The parameters are available for the Real Imaginary result types TRACelI TRACe2l TRACe3l The imaginary data from the corresponding trace The parame ters are available for the Real Imaginary result types Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 11 9 2 Measurement Results for TRACe lt n gt DATA lt gt The evaluation data source selected by the LAY ADD WIND command and the result type selected by the CALCulate lt n gt FORMat command also affect the results of the trace data query see TRACe lt n gt DATA lt gt Details on the returned trace data depending on the evaluation data source and result type are provided here e Capture Buffer 375 e cedere cedet cd etd de ex 376 e Polar Diagrams tiec te c E 376 376 Result ees 376 6 BQUANZ SR m
477. r in the captured signal are predefined in the VSA application In addition new patterns can be defined and assigned to a signal standard manually Patterns are configured in the Advanced Pattern Settings dialog box which is dis played when you do one of the following e Select the Pattern Config softkey the main VSA menu e Inthe Signal Description dialog box see chapter 5 4 Signal Description on page 134 switch to the Signal Structure tab and select the Pattern Config button Burst and Pattern Configuration Adv nced P x Standard Patterns Pattern Details Name EDGE TSCO Description EDGE Norma Comment Training Sequence Code Modulation Order 5 AllPatterns Prefix Show Compatible Show EDGE_TSCO Pattern Search On Meas only if Pattern Symbols Correct Standard Patterns selecting an assigned 11 169 Removing patterns from a standard 2 nih Lea eire Hace ape 170 Adding patterns to a statdald reir tetur rte RR Rx 170 Displaying available 1 170 Bu E 170 L Show Compatible Show All eene 170 o M ERE DETECTED 170 SLUT 170 INOW seve 170 Delelg oti
478. rameters lt Magnitude gt The number is a statistical value and therefore dimensionless Range 1E 9 to 0 1 RST 1E 6 Example CALC STAT SCAL Y LOW 0 001 Manual operation See Defining Min and Max Values on page 152 CALCulate lt n gt STATistics SCALe Y UPPer lt Magnitude gt This command defines the upper vertical limit of the diagram Configuring VSA Parameters lt Magnitude gt The number is a statistical value and therefore dimensionless Range 1E 5 to 1 0 RST 1 0 Example CALC STAT SCAL Y UPP 0 01 Manual operation See Defining Min and Max Values on page 152 CALCulate lt n gt STATistics SCALe Y UNIT lt Unit gt This command selects the unit of the y axis Parameters lt Unit gt PCT ABS RST ABS Example CALC STAT SCAL Y UNIT PCT Sets the percentage scale Manual operation See Y Axis Unit page 154 CALCulate lt n gt UNIT ANGLe lt Unit gt This command selects the global unit for phase results Setting parameters lt Unit gt DEG RAD RST RAD Manual operation See Y Axis Unit on page 154 CALCulate lt n gt X UNIT TIME lt Unit gt This command selects the unit symbols or seconds for the x axis Setting parameters lt Unit gt S SYM RST SYM Manual operation See X Axis Unit on page 154 CALCulate lt n gt Y UNIT TIME lt Unit gt This command selects the unit symbols or seconds for the y ax
479. ration See Load Standard on page 131 SENSe DDEMod STANdard COMMent Comment This command enters the comment for a new standard The comment is stored with the standard and is only displayed in the selection menu manual operation When remote control is used the string is deleted after the standard has been stored allow ing a new comment to be entered for the next standard In this case a blank string is returned when a query is made Setting parameters Comment string Manual operation See Comment on page 131 SENSe DDEMod STANdard DELete lt FileName gt This command deletes a specified digital standard file in the vector signal analysis The file name includes the path If the file does not exist an error message is displayed Configuring VSA Setting parameters lt FileName gt string File name including the path for the digital standard file Usage Setting only Manual operation See Delete Standard on page 131 SENSe DDEMod STANdard PREset VALue This command restores the default settings of the currently selected standard Usage Event SENSe DDEMod STANdard SAVE lt FileName gt This command stores the current settings of the vector signal analysis as a new user defined digital standard If the name of the digital standard is already in use an error message is output and a new name has to be selected It is recommended that you define a comment before storing the standard Setting parame
480. requencies Remote command INPut GAIN STATe on page 294 Output Settings The R amp S FPS VSA application can provide trigger output to other devices For details on connectors refer to the R amp S FPS Getting Started manual Front Rear Panel View chapters Output settings can be configured via the INPUT OUTPUT key or in the Outputs dia log box Output Digital IQ IF Video Output IF Out Frequency Trigger 2 Trigger 3 IENIDEQ Output EU 144 TIIT 2 S AAO 144 L Output TYDE rarm deae rae 145 uro E n 145 145 L Send TMOJE a 145 IF VIDEO Output Defines the type of signal available at the IF VIDEO on the rear panel of the R amp S FPS For restrictions and additional information see the R amp S FPS Analyzer and Input User Manual IF The measured IF value is available at the IF VIDEO output connector VIDEO The displayed video signal i e the filtered and detected IF signal is available at the IF VIDEO output connector This setting is required to provide demodulated audio frequencies at the output Remote command OUTPut IF SOURce on page 289 Trigger 2 Defines the usage of the variable TRIGGER AUX connector on the rear panel Input Output and Frontend Settings Trigger 1 is INPUT only Note Providing trigger signals as output is described in detail in the R amp S FPS User Manual Input The signal at
481. required source type see LAYout ADD WINDow page 359 CALC FORM RCON to define the result type see CALCulate lt n gt FORMat on 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 3 Polar Diagrams on page 376 3 2 7 Error Vector Magnitude EVM Displays the error vector magnitude as a function of symbols or time EVM t E with and duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 The normalization constant C is chosen according to the EVM normalization By default C is the mean power of the reference signal x Xen and T duration of symbol periods Note that k 0 5 n T for Offset QPSK with inactive Offset EVM User Manual 1176 8516 02 06 26 R amp S FPS K70 Measurements and Result Displays ei Clrw 49 sym Fig 3 5 Result display Error Vector Magnitude Available for source types e Error Vector Remote commands LAY ADD 1 BEL EVEC to define the required source type see LAYout ADD WINDow page 359 CALC FORM MAGN to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 3 2 8 Eye Diagram Freq
482. rigger pulse level is always opposite to the constant signal level defined by the output Level setting e g for Level High a constant high signal is output to the connector until the Send Trigger button is selected Then a low pulse is sent Which pulse level will be sent is indicated by a graphic on the button Remote command OUTPut TRIGger lt port gt PULSe IMMediate on page 290 Input Output and Frontend Settings 5 5 3 Frequency Settings Frequency settings for the input signal can be configured via the Frequency dialog box which is displayed when you do one of the following Select the FREQ key and then the Frequency Config softkey e Select the Frequency tab in the Input Settings dialog box Center Frequenc Frequency Offset e mnic dii et s A 146 Center Frequency ep e hec itd atit de 146 Frequency diete ide V 147 Center frequency Defines the normal center frequency of the signal The allowed range of values for the center frequency depends on the frequency span span gt 0 spanmin 2 S foenter lt fmax SPANmin 2Z fmax and span i depend on the instrument and are specified in the data sheet Remote command SENSe FREQuency CENTer on page 291 Center Frequency Stepsize Defines the step size of the center frequency The step size can be set to a predefined value or it can be manuall
483. rrr pt en ee Co etre rapuere sente re erase DISPlayEWINBOWStis ZOOM AREA 1 uc tte ttp tt tene tea pete ved p e lt gt 7 lt 2 gt DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt STATe DISPlayEWINDowsn ZOOM S TAT6 ient ren tnnt rer reete tne ree ees FORMaEtDEXPort rien ncn tv eere E er Veg re nears xe tris dendo mI n FORMat DEXPort MODE odes pee tpa ree rece cp e THEM ere t s pe V Dave INMtTiate REEMGAS eee INimiatesn gt c INITiate lt n gt CONTinuous gt eee in E nian Beene INITiiatesms SEQuencerABORLE INI Tiate ns SEQuencerIMMediale tpe depu uds INITiate lt n gt SEQuencer MODE INITiatesnz SEQuencer REFResh AEL scant eo aee egere nuevo Uo ee rcr KEDE n espe ege ke INITiate n IMMediate rr trn tr rr rrt e nnt rerit INPUEA MIN FUE AST SMAI INPut AT Tenuation PRO T6ection RESOGL tiere
484. rt from the configuration described in chapter 9 3 4 Evaluating the Rising and Falling Edges on page 240 Select window 4 to set the focus on it Press the TRACE key and then the Trace 2 softkey Select Clear Write as the Trace Mode and Evaluation Ref This adds a sec ond trace to your result display This trace is the ideal reference signal that can now be compared to the measurement signal see figure 9 12 pum EIN NDA CN V UU User Manual 1176 8516 02 06 242 R amp S FPS K70 Measurement Examples 5 To view the traces in more detail enlarge the window using the Split Maximize key and zoom into the display using the icon in the toolbar see the dot ted rectangle in figure 9 12 Spectrum VSA Ref Level 4 00 dBm Att 24dB Freq 1 0 GHz BURST PATTERN D MagAbs Meas amp Ref 1M 2R Std EDGE_8PSK SR 270 833 kHz Res Len 200 Stop 174 sym Start 26 sym Fig 9 12 Zooming Now you can compare the measured and the ideal reference signal P M c nl 243 User Manual 1176 8516 02 06 Flow Chart for Troubleshooting 10 Optimizing and Troubleshooting the Mea surement If the results do not meet your expectations the following tips may help you optimize or troubleshoot the measurement 10 1 Flow Chart for Troubleshooting ssesssssseseseee eene 244 Explanation of Error MeSSaQels i
485. s OUTPut IF SOURce Source Defines the type of signal available at the IF VIDEO or IF OUT 2 GHZ connector of the R amp S FPS Parameters lt Source gt IF The measured IF value is available at the IF VIDEO output con nector viDeo The displayed video signal i e the filtered and detected IF sig nal 200mV is available at the IF VIDEO output connector This setting is required to provide demodulated audio frequen cies at the output RST IF Example OUTP IF VID Selects the video signal for the IF VIDEO output connector Manual operation See IF VIDEO Output on page 144 OUTPut TRIGger lt port gt DIRection Direction This command selects the trigger direction for trigger ports that serve as an input as well as an output Suffix port Selects the used trigger port 2 AUX Parameters Direction INPut Port works as an input OUTPut Port works as an output RST INPut Manual operation See Trigger 2 on page 144 OUTPut TRIGger lt port gt LEVel lt Level gt This command defines the level of the signal generated at the trigger output This command works only if you have selected a user defined output with OUTPut TRIGgereport OTYPe Configuring VSA Suffix port Selects the trigger port to which the output is sent 2 AUX Parameters Level HIGH TTL signal LOW OV RST LOW Manual operation See Trigger 2 on page 144 See Level on page 145 OUTPut
486. s a falsely estimated reference signal due to false symbol decisions is avoided and does not influence the error calculation You can load xml files containing the possible sequences to the VSA application and use them to compare the measured data to In particular you can use known data for the following functions e Fine synchronization during the demodulation process see figure 4 42 and Fine Synchronization on page 183 e Calculation of the Bit Error Rate BER see chapter 3 2 1 Bit Error Rate BER on page 20 For details on working with Known Data files see chapter 8 2 3 How to Manage Known Data Files on page 218 Auxiliary tool to create Known Data files An auxiliary tool to create Known Data files from data that is already available in the VSA application is provided with the R amp S FPS free of charge See chapter 8 2 3 2 How to Create Known Data Files on page 219 The syntax for Known Data files is described in chapter A 5 Known Data File Syntax Description on page 423 When you use Known Data files as a reference some dependencies to other settings and restrictions for other functions apply Modulation Order The Modulation Order selected in the Modulation settings in the VSA application must correspond to the modulation order value specified in the xml file lt ModulationOr der gt element R amp S FPS K70 Measurement Basics Demodulation Demodulation using synchronization t
487. s Len 148 Input RF CERT o Start 101 562 kHz Stop 101 562 kHz Start 101 562 kHz Stop 101 562 kHz ul 1M WR BI adea La nna 1 lite Start 0 sym Stop 148 sym Fig 6 1 Statistics measurement window C measured signal symbols highlighted window A sta tistics for all trace points window B statistics for symbol instants only Symbols only Statistics are calculated for symbol instants only See window B in figure 6 1 Infinite Statistics are calculated for all trace points symbol instants and inter mediate times See window A in figure 6 1 Auto Oversampling is automatically set to Symbols only Statistics are calculated for symbol instants only Remote command CALCulate lt n gt STATistics MODE on 368 Zoom Functions The zoom functions are only available from the toolbar SHINS aoo E 205 ZO E 205 Restore Onginal DISp ay 20 onere ddr tee can tdt 205 Deactivating Zoom Selection mode tenentes 205 Zoom Functions Single Zoom ER A single zoom replaces the current diagram by a new diagram which displays an enlarged extract of the trace This function can be used repetitively until the required details are visible Remote command DISPlay WINDow lt n gt ZOOM STATe on
488. s amp Ref BI Q Vector Meas amp Ref amp 1M Cirw Stop 2 91 Start 2 91 Stop 2 91 DI Q Vector Meas amp Ref 1M Cirw XA 2 Start 2 91 Stop 2 91 2 Stop 2 91 Fig 4 67 Result display with different numbers of points per symbol window A 7 window B 2 window C 4 window D 16 The displayed points per symbol also determine how many values are returned when the trace data is queried by a remote command see TRACe lt n gt DATA on page 374 For results based on the capture buffer one display point is displayed for each sam ple taken i e the display points per symbol are always identical to the sample rate For the Result Summary the number of display points corresponds to the estimation points per symbol By default 1 for QAM and PSK modulated signals and the sample Capture Buffer Display rate for MSK and FSK modulated signals This value also controls which samples are considered for the peak and RMS values and the power result For all other result displays the default number of displayed points per symbol is iden tical to the sample rate 4 8 Capture Buffer Display In previous firmware versions the capture length in the R amp S FPS VSA application was restricted to 256 000 samples As of firmware version 2 00 up to 200 million symbols can be captured and processed at a time Processing large numbers of samples If more than 256 000 samp
489. s are already integrated in the VSA application In addition it is possible to use user defined measurement and transmit filters Customized filters may be useful for the following purposes Development of new networks and modulation methods for which no filters are defined yet Measurements of transmitter characteristics with slightly modified e g shortened transmitter filters An external program FILTWIZ is offered to convert user defined filters This pro gram generates filter files vaf which can be transferred to the analyzer with a USB device for example The program can be downloaded together with a detailed descrip tion as a precompiled MATLABO file MATLAB pcode on the Internet at http www rohde schwarz com search term FILTWIZ Filters and Bandwidths During Signal Processing Rohde amp Schwarz Filter Wizard Version 1 5 xi File operations File name MyFilter vaf Load Save Save Exit Description File info user specific fitter 0 035 RRC alpha 0 22 L 10 ISI_LSNR 16 5 dB 0 03 0 025 0 02 0 015 hi 0 01 0 005 tin ya Sai Fig 4 4 FILTWIZ filter tool for VSA It is possible to load customized transmit filters and customized measurement filters If a customized transmit filter is selected the internal receive filter coefficients are calcu lated automatically on the fly Note that this is different to the R amp S FSQ K70 where it is necessary t
490. s set to Auto mode the known data is also used for synchronization Otherwise it can be selected manually Defining a maximum symbol error rate for the known data in ref erence to the analyzed data avoids using a falsely selected or unsuitable file for synchronization see also If SER lt on page 184 How to Perform Customized Measurements 8 2 3 2 How to Create Known Data Files You must create the Known Data files yourself according to the possible data sequen ces of the input signal Use any xml editing tool you like following the rules described in chapter A 5 Known Data File Syntax Description on page 423 Before loading the file to the VSA application make sure the syntax of your file is valid Auxiliary tool to create Known Data files An auxiliary tool to create Known Data files from data that is already available in the VSA application is provided on the instrument free of charge To create a Known Data file using the recording tool for sequences 1 Import or apply input data for which stable demodulation results are available to the VSA application If necessary adapt the demodulation settings until the requested results are obtained 2 Start the R amp S Recording Tool for Sequences from the Windows task bar on the R amp S FPS or execute the file RecordingToolforSequences EXE from the installation directory on the instrument The R amp S Recording Tool for Sequences window is displayed
491. s the selected user defined modulation loaded from a file For more information on these modulation types see chapter 4 3 Symbol Mapping on page 67 Remote command SENSe DDEMod FORMat on page 278 Load User Modulation Modulation Type This function is only available if the modulation type User Modulation is selected Opens file selection dialog box to select the file that contains the user defined modu lation vam file For details on user defined modulation files see chapter 4 3 11 User defined Modula tion on page 87 Remote command SENS DDEM FORM UQAM see SENSe DDEMod FORMat on page 278 SENSe DDEMod USER NAME on page 284 Modulation Order Depending on the Modulation Type various orders of modulation are available Type Available orders PSK BPSK 3Pi 4 QPSK Pi 8 D8PSK QPSK 8PSK DQPSK Offset QPSK 8 8 5 Pi 4 DQPSK Pi 4 QPSK D8PSK MSK MSK DMSK QAM 16QAM Pi 4 32QAM 256QAM Pi 4 16QAM 64QAM 512QAM 32QAM 128QAM 1024QAM FSK 2FSK 4FSK 8FSK Signal Description Type Available orders ASK 2ASK 4ASK APSK 16APSK 32APSK Remote command PSK SENSe DDEMod PSK FORMat on page 280 SENSe DDEMod PSK NSTate on page 281 SENSe DDEMod QPSK FORMat on page 282 MSK SENSe DDEMod MSK FORMat on page 280 QAM SENSe DDEMod QAM FORMat on page 281 SENSe DDEMod QAM
492. scccccsscsscscsssscsetssesesesesescseseseeeesesenenesesenees 140 M TNT 140 rcr o 140 Pattern Setilngs petas terr certc enti d D ct td 140 es WR 140 ee nose destitit tubo ad 140 E 141 Signal Type Determines whether the signal is continuous or contains bursts Remote command SENSe DDEMod SIGNal VALue on page 286 e VV C LAL LEAAI MLLC S A lgAULLL ii A3BbA A bbA ie bh eon User Manual 1176 8516 02 06 139 Signal Description Burst Settings For bursts further settings are available Min Length Max Length Burst Settings Shortest and longest expected burst length in symbols 32000 The symbols are con verted to seconds for reference Remote command SENSe DDEMod SEARch BURSt LENGth MAXimum on page 285 SENSe DDEMod SEARCh BURSt LENGth MINimum on page 285 prog Run In Burst Settings The number of symbols before the signal is assumed to have valid modulated symbols The symbols are converted to seconds for reference Remote command SENSe DDEMod SEARch BURSt SKIP RISing on page 286 Run Out Burst Settings The number of symbols before the falling edge that do not necessarily need to have a valid modulation The symbols are converted to seconds for reference Remote command SENSe D
493. scription consists of information on the used modulation and on the signal s structure COGNAC TOT EET ETE 134 e DOnna iudei e A t Ee aie eee 138 KONN 141 5 4 1 Modulation The Modulation settings contain modulation and transmit filter settings A live preview of the Constellation trace using the currently defined settings is displayed at the bottom of the dialog box to visualize the changes to the settings The preview area is not editable directly The modulation settings vary depending on the selected modulation type in particular FSK modulation provides some additional settings The Modulation settings are displayed when you do one of the following e Select the Signal Description button in the Overview Select the Signal Description softkey in the main VSA menu R amp S FPS K70 Configuration Modulation Signal Structure Known Data Modulation Settings Mapping FSK Ref Deviation 1 0 SR Symbol Rate Transmit Filter Alpha BT Preview Preview Constellation Freq Meas amp Ref Start 30 758 MHz Stop 30 758 MHz Fig 5 1 Signal modulation settings for FSK modulation Modulation Type Defines the modulation type of the vector signal The following types are available e PSK e MSK e QAM User Manual 1176 8516 02 06 135 Signal Description FSK ASK APSK User Modulation Use
494. spectrum displays 11 5 11 Configuring VSA Suffix lt startstop gt 1 2 irrelevant Setting parameters lt Auto gt ON OFF 1 0 ON The evaluation range extends from the start value defined by CALC ELIN1 VAL to the stop value defined by CALC ELIN2 VAL see CALCulate lt n gt ELIN lt startstop gt VALue on page 329 OFF The complete result area is evaluated RST OFF Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Evaluating the Entire Result Range on page 188 CALCulate lt n gt ELIN lt startstop gt VALue lt LeftDisp gt Defines the start and stop values for the evaluation range see CALCulate lt n gt ELIN startstop STATe on page 328 Suffix lt startstop gt 1 2 1 start value 2 stop value Setting parameters lt LeftDisp gt numeric value Range 0 to 1000000 RST 0 Default unit SYM Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual operation See Start Stop on 188 Adjusting Settings Automatically Some settings can be adjusted by the R amp S FPS automatically according to the current measurement settings Manual execution of automatic adjustment functions is described in chapter 5 12 Adjusting Settings Automatically on page 188 DISPlay WINDow
495. st signal but is so highly dis torted that the burst search cannot detect a burst the estimation range corresponds to the pattern and if an offset of the pattern is indicated the useful part of the burst from its start to the pattern start Signal Model Estimation and Modulation Errors 4 5 1 3 Modulation Errors Error vector EV Q Fig 4 51 Modulation error error vector The error vector is the difference between the measurement signal vector Meas vec tor and the reference signal vector Ref vector Error Vector Magnitude EVM Q Fig 4 52 Modulation error EVM magnitude error phase error The magnitude of the error vector in the diagram is specified as the error vector magni tude EVM It is commonly normalized to the mean reference power or alternatively to the maximum reference power or the mean or maximum constellation power power at the symbol instants see Normalize EVM to on page 181 The EVM should not be confused with the magnitude error see below Signal Model Estimation and Modulation Errors Magnitude Error The magnitude error is defined as the difference between the measurement vector magnitude and the reference vector magnitude see figure 4 52 Phase Error Q Fig 4 53 Modulation error Phase error error vector phase The phase error is the phase difference between the measurement vector and the ref erence vector PHASE _ ERR
496. stage operates on the extracted result range and aims at making the correct sym bol decisions Within this stage a coarse synchronization of the carrier frequency off Set the carrier phase the scaling and the timing takes place Furthermore an auto matically selected internal receive filter Rx filter is used in order to remove the inter symbol interference as effectively as possible The outputs of this stage are the coarsely synchronized measurement signal and the symbol decisions bits The symbol decisions are later used for the Pattern Symbol Check stage and for the Ref erence Signal Generation stage User Manual 1176 8516 02 06 89 4 4 1 Overview of the Demodulation Process Pattern Symbol Check The I Q Pattern Search stage can only detect whether the similarity between the pattern and the capture buffer exceeds a certain threshold and in this way find the most likely positions where a pattern can be found Within this stage the VSA application checks whether the pattern symbols bits really coincide with the symbol decisions at the pre detected position For example if one out of 20 symbols does not coincide the I Q Pattern Search stage might detect this pattern but the Pattern Symbol Check stage will decline it Note that this stage is only active if the pattern search is switched on If individual symbols do not match the pattern these symbols are indicated by a red frame in the symbol tab
497. stem Theoretical Modulation and Demodulation Filters MEAS filter Measurement Filter Weighting filter for the measure ment System Theoretical Modulation and Demodulation Filters MSK Minimum Shift Keying Modulation mode Minimum Shift Keying MSK NDA Demodulator Non Data Aided Demodulator Demodulation without any knowl edge of the sent data contents Demodulation and Algorithms PSK Phase Shift Keying Modulation mode for which the information lies within the phase or within the phase transitions Phase Shift Keying PSK QAM Quadrature Amplitude Modulation Modulation mode for which the information is encrypted both in the amplitude and phase Quadrature Amplitude Modulation QAM Predefined Standards and Settings Abbreviation Meaning See section RMS Root Mean Square Averaging RMS Quantities RX filter Receive Filter System Theoretical Modulation Baseband filter in analyzer used and Demodulation Filters for signal adapted filtering Transmit filter Transmitter Filter System Theoretical Modulation Digital impulse shaping filter in and Demodulation Filters signal processing unit of transmit ter VSA Vector Signal Analysis Measurement at complex modula ted RF carriers A 2 Predefined Standards and Settings In the Digital Standards menu predefined basic settings for standards can be selected and user defined standards stor
498. symbols The value can also be given in seconds Setting parameters lt MaxLength gt numeric value Range 0 to 32000 RST 1600 Default unit SYM Manual operation See Min Length Length on page 140 SENSe DDEMod SEARch BURSt LENGth MINimum lt UsefulLength gt This command defines the minimum useful length of a burst Only those bursts will be recognized that exceed this length The default unit is symbols The value can also be given in seconds Note the difference to manual operation lt Min_length gt anuai Min Useful Length lt Run In gt lt Run Out gt Setting parameters lt UsefulLength gt numeric value Range 10 to 32000 RST 100 Default unit SYM Manual operation See Min Length Length on page 140 SENSe DDEMod SEARch BURSt SKIP FALLing lt RunOut gt This command defines the length of the falling burst edge which is not considered when evaluating the result The default unit is symbols The value can also be given in seconds Setting parameters lt RunOut gt numeric value Range 0 to 31990 RST 1 Default unit SYM Manual operation See Run Out on page 140 Configuring VSA SENSe DDEMod SEARch BURSt SKIP RISing lt gt This command defines the length of the rising burst edge which is not considered when evaluating the result The default unit is symbols The value can also be given in sec onds Setting parameters Runin numeric value
499. symbols displayed in the status bar his can be problematic If you have a pattern you can try to use it for synchronization i e use the setting Coarse Synchronization Pattern Demodulations Advanced dialog you increase the length of your Result Range Is your burst possibly larger Coarse Synchr Increase the Result Range to at least 8xModulation Order Go back to Do you transmit uncor related random bits on the physical level your Result Range large than 8xModulation Order e g 8x4 32 for QPSK no i Try to switch on the equalizer in the Demodulation dialog and compensate for the channel Y Try to compensate for the symbol rate error in the Demodulation dialog Hard to find the origin of the problem It might be that Your DUT suffers from massive impairments Your DUT suffers from a severe symbol rate error The adjacent channel power is very high Explanation of Error Messages no From 1 no Is your signal bursted yes Does your signal contain pattern S this pattern relevant e g to align your result to the pattern or to check whether the pattern is transmitted correctly Does your signal consist of ranges with different modulation types no omm EDGE MSR arsi pat
500. t gt lt gt 8 2 342 lt gt lt gt 5 342 Analysis CALC ulatesn gt DEL Tamarkersin gt RACE securite anota n o axe trt ee Ea 343 GALGulate n DELTarmarkerem X EEEE Ee o Can Era ca 343 CAL GulatesmDELETAmatkeremsY 7 oov uoce t a paucis Fa ck Loo d ra 343 CALCulate lt n gt MARKer lt m gt AOFF This command turns all markers off Example CALC MARK AOFF Switches off all markers Usage Event Manual operation See All Markers Off on page 196 CALCulate lt n gt MARKer lt m gt LINK lt MarkerCoupling gt With this command markers between several screens can be coupled i e use the same x value All screens can be linked with the marker x value scaled in symbols or time except those showing the capture buffer If several capture buffer measurements are visible their markers are coupled too Setting parameters lt MarkerCoupling gt OFF 1 0 RST 0 Manual operation See Couple Windows on page 196 CALCulate lt n gt MARKer lt m gt STATe State This command turns markers on and off If the corresponding marker number is cur rently active as a deltamarker it is turned into a normal marker Parameters lt State gt ON OFF RST OFF Example CALC MARK3 ON Switches on marker 3 Manual operation See Marker State on page 195
501. t lt ChannelName gt STATus QUEStionable MODulation lt n gt EVM ENABle BitDefinition lt ChannelName gt STATus QUEStionable MODulation lt n gt FSK ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt IQRHo ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt MAGNitude ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable MODulation lt n gt PHASe ENABle lt BitDefinition gt lt ChannelName gt STATus QUEStionable POWer ENABle lt BitDefinition gt STATus QUEStionable SYNC ENABle lt BitDefinition gt lt ChannelName gt This command controls the ENABle part of a register The ENABle part allows true conditions in the EVENt part of the status register to be reported in the summary bit If a bit is 1 in the enable register and its associated event bit transitions to true a positive transition will occur in the summary bit reported to the next higher level Parameters lt BitDefinition gt Range 0 to 65535 lt ChannelName gt String containing the name of the channel The parameter is optional If you omit it the command works for the currently active channel STATus QUEStionable ACPLimit NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable DIQ NTRansition lt BitDefinition gt lt ChannelName gt STATus QUEStionable FREQuency NTRansition lt BitDefinition gt lt ChannelName gt User Manual 1176 8516 02 06 4
502. t in the result summary for the current evaluation range Result df Storing trace data to a file FORM DEXP HEAD ON Include a header in the trace export file FORM DEXP MODE TRAC Export the trace data not raw I Q data DISP WIND1 TRAC2 X STAR Query the first value of the x axis for the current result range x values are not exported with trace data Result MMEM STOR4 TRAC 1 Measurement signal Save the measurement signal values trace 1 in window 4 to an ascii file Results MMEM STOR4 TRAC 2 Reference signal Save the reference signal values trace 2 in window 4 to an ascii file Results MMEM STOR2 TRAC 1 Result Summary Save the result summary values window 2 for the current result range to an ascii file Results Retrieving results for further result ranges gt DDEM SEAR MBUR CALC Query the number of result ranges current is last Use variable x to determine number of previous result range DDEM SEAR MBUR CALC x 11 13 3 Programming Examples Move to next result range and repeat section retrieving results for range specific results Measurement Example 3 User Defined Pattern Search and Limit Check In this example a user defined pattern is used to detect bursts and the calculated mea surement results are checked against defined limits The configuration settings are
503. t MAC Curacy FDERror PEAK RESult CALCulate lt n gt LIMit MAC Curacy FERRor PCURrent RESUIt CALCulate lt n gt LIMit MACCuracy FERRor PMEan RESult CALCulate lt n gt LIMit MAC Curacy FERRor PPEak RESult CALCulate lt n gt LIMit MAC Curacy FERRor RCURrent RESult CALCulate lt n gt LIMit MACCuracy FERRor RMEan RESult CALCulate lt n gt LIMit MACCuracy FERRor RPEak RESult CALCulate lt n gt LIMit MAC Curacy MERRor PCURrent RESult CALCulate lt n gt LIMit MACCuracy MERRor PMEan RESult CALCulate lt n gt LIMit MACCuracy MERRor PPEak RESult CALCulate lt n gt LIMit MAC Curacy MERRor RCURrent RESult CALCulate lt n gt LIMit MAC Curacy MERRor RMEan RESult CALCulate lt n gt LIMit MAC Curacy MERRor RPEak RESult User Manual 1176 8516 02 06 388 R amp S FPS K70 Remote Commands for VSA CALCulate lt n gt LIMit MACCuracy OOFFset CURRent RESult CALCulate lt n gt LIMit MACCuracy OOFFset MEAN RESult CALCulate lt n gt LIMit MACCuracy OOFFset PEAK RESult CALCulate lt n gt LIMit MACCuracy PERRor PCURrent RESult CALCulate lt n gt LIMit MACCuracy PERRor PMEan RESult CALCulate lt n gt LIMit MACCuracy PERRor PPEak RESult CALCulate lt n gt LIMit MACCuracy PERRor RCURrent RESult CALCulate lt n gt LIMit MACCuracy PERRor RMEan RESult CALCulate lt n gt LIMit MACCuracy PERRor RPEak RESult CALCulate lt n gt LIMit MACCuracy RHO CURRent RESult CALCulate lt n gt LIMit MACCuracy RHO MEAN RE
504. t 11 353 lt gt 11 17 389 lt gt 11 5 eene enne 350 lt gt 1 nnne 353 lt gt 11 2 389 lt gt 11 5 350 lt gt 11 353 lt gt 11 2 389 lt gt 11 5 350 lt gt 11 353 lt gt 11 389 CALCulate lt n gt LIMit MACCuracy PERRor PMEan STATe CALCulate lt n gt LIMit MACCuracy PERRor PMEan VALue CALOCulate n LIMit MACCuracy PERRor PMEan RESUlt esee 389 CALOCulate n LIMit MACCuracy PERRor
505. tage has already been described in the context of the Demodulation amp Symbol Decisions block see chapter 4 4 3 Demodulation and Symbol Decisions on page 93 The second stage is realized within the Synchronization block Here the measure ment signal is matched to the reference signal by minimizing the mean square of the error vector magnitude This is done by selecting the optimum parameter vector 5 arg 8 The minimization takes place at the sample instants specified by the Estimation Points Sym parameter i e t n Tg with Tg the sampling period used for estimation Subsequently the measurement signal is corrected with the determined parameter vector Note that with a subset of the parameters you can enable or disable correction see chapter 5 9 1 Demodulation Compensation on page 176 Estimation ranges The estimation ranges are determined internally according to the signal description For continuous signals the estimation range corresponds to the entire result range since it can then be assumed that the signal consists of valid modulated symbols at all time instants e For bursted signals the estimation range corresponds to the overlapping area of the detected burst and the Result Range Furthermore the Run In Run Out ranges see Burst Settings on page 140 are explicitly excluded from the estima tion range In the special case that the signal is indicated as a bur
506. tenance instrument interfaces and troubleshooting In the individual application manuals the specific instrument functions of the applica tion are described in detail For additional information on default settings and parame 1 3 Typographical Conventions ters refer to the data sheets Basic information on operating the R amp S FPS is not inclu ded in the application manuals user manuals are also available for download from the Rohde amp Schwarz website on the R amp S FPS product page at http Awww2 rohde schwarz com product FPS html Service Manual This manual is available in PDF format on the Documentation CD ROM delivered with the instrument It describes how to check compliance with rated specifications instru ment function repair troubleshooting and fault elimination It contains all information required for repairing the R amp S FPS by replacing modules Release Notes The release notes describe the installation of the firmware new and modified func tions eliminated problems and last minute changes to the documentation The corre sponding firmware version is indicated on the title page of the release notes The most recent release notes are also available for download from the Rohde amp Schwarz website on the R amp S FPS product page at http www2 rohde schwarz com product FPS html gt Downloads gt Firmware Typographical Conventions The following text markers are used throughout this documentati
507. tenuation gt attenuation in dB Range see data sheet Increment 1 dB RST 0 dB OFF Example INP EATT AUTO OFF INP EATT 10 dB Manual operation See Using Electronic Attenuation on page 150 INPut EATT AUTO State This command turns automatic selection of the electronic attenuation on and off If on electronic attenuation reduces the mechanical attenuation whenever possible This command requires the electronic attenuation hardware option Parameters State OFF 0 1 RST 1 Example INP EATT AUTO OFF Manual operation See Using Electronic Attenuation on page 150 11 5 2 6 Configuring VSA INPut EATT STATe State This command turns the electronic attenuator on and off This command requires the electronic attenuation hardware option Parameters State OFF RST OFF Example INP EATT STAT ON Switches the electronic attenuator into the signal path Manual operation See Using Electronic Attenuation on page 150 Scaling and Units Useful commands for scaling described elsewhere DISPlay WINDow n TRACe t Y SCALe AUTO ONCE on page 330 DISPlay WINDow lt n gt TRACe lt t gt X SCALe VOFFset on 317 Remote commands exclusive to scaling and units lt gt 5 5 296 CALCulatespns STATIstics SCAEe AUTO ONGE 2 tnit atate en tete exse reden 297
508. ter 8 2 3 How to Manage Known Data Files on page 218 Additional information provided by the loaded file is displayed at the bottom of the dia log box This information is not editable directly The Known Data settings are displayed when you do one of the following e Select the Signal Description button in the Overview e Select Signal Description softkey the main VSA menu Then switch to the Known Data tab Modulation amp Signal Description Known Data Known Data is needed for the BER measurement and can be used for fine synchronization see Demodulation dialog Known Data Filename KnownData example xml Load Data File Additional Information Result Length 148 Number of Sequences 5 Modulation Order 8 Base Hexadecimal Comment Standard EDGE 8PSK Input Output and Frontend Settings Auxiliary tool to create Known Data files An auxiliary tool to create Known Data files from data that is already available in the VSA application is provided on the instrument free of charge See To create a Known Data file using the recording tool for sequences on page 219 Know EE rime 142 aT C 142 Known Data Activates or deactivates the use of the loaded data file if available When deactivated the additional information from the previously loaded data file is remov
509. ter performing certain operations e g changing the modulation settings the pat tern will be included in the list of All Patterns again How to Manage Known Data Files You can load xml files containing the possible sequences to the VSA application and use them to compare the measured data to In particular you can use known data for the following functions e Fine synchronization during the demodulation process see figure 4 42 and Fine Synchronization on page 183 Calculation of the Bit Error Rate BER see chapter 3 2 1 Bit Error Rate BER on page 20 How to Load Known Data Files Known Data files are loaded in the Modulation amp Signal Description settings To load an existing Known Data file 1 In the Overview select Signal Description 2 Switch to the Known Data tab 3 Activate the usage of a Known Data file by enabling the Known Data option This enables the Load Data File function 4 Select the Load Data File button A file selection dialog box is displayed 5 Select the xml file which contains the possible data sequences of the input signal The file must comply with the syntax described in chapter A 5 Known Data File Syntax Description on page 423 The header information of the xml file is displayed in the dialog box Once a Known Data file has been loaded the Bit Error Rate result display becomes available If the Fine Synchronization setting in the Demodulation dialog box i
510. tern coni 0 05 Make sure your Signal Type in the Signal Description dialog is a Burst Signal Make sure the pattern is indicated in the Signal Description dialog se the Offset and Result Length parameters in the Result Range dialog to move your result range to the desired point in the capture buffer Make sure the burst search is switched on in the Burst Search dialog Make sure the pattern search is switched on yes Is Burst Not Found displayed in the status bar you see a Pattern Not Found Message se an external trigger and appropriate trigger offset Go back to Make sure your Make sure your Result Range Alignment Result Range Alignment reference is Burst reference is Pattern Waveform Range Settings dialog Range Setting Dialog Go back to 10 2 Explanation of Error Messages The following section describes error messages and possible causes Message Burst Not Found rre e ie metet Rn eda iue Message Pattern Not 02 1 2 2 2 teet Message Result Alignment Failed Message Pattern Search On But No Pattern Selected Message Pattern Not Entirely Within Result Message Short Pattern Pattern Search Might
511. ters lt FileName gt string The path and file name to which the settings are stored Example DDEM STAN COMM GSM AccessBurst with Pattern Defines a comment for the settings DDEM STAN SAVE C R_S Instr usr standards USER_GSM Stores the settings in the user defined digital standard USER_GSM Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Usage Setting only Manual operation See Save Standard on page 131 11 5 Configuring VSA e Signal Deschiptlon 2 2 rite die Fete 276 Input Outpul and Frontend Settings 2 ette rentre ttes 287 Signal Caplule eet ei Ge pire crc tre Ip c Y E E EE ER 301 e Triggerimng MedsUremeOlls oe c ite rac ERE E 303 e Configuring SWOODS reciente e RE NE ATH 307 Configuring Bursts abd cete eee cet eed e teh 308 Denning the Result eoo epe tet Er aee EE nad reped Re 315 e Demodulation Settings ssenarisinin iinun naiwan in igi iiiaae 318 11 5 1 11 5 1 1 Configuring VSA e Measurement Filter Sells uere tite dnce net ete 326 Defining the Evaluation Range re rr Free edens 328 e Adjusting Settings Automatically eese nennen 329 Signal Description The signal description provides inf
512. ti deae cb rne EE rn er pee cn pend eee duod n er 47 LEE nos Ed 51 Vector Fregnir aen aaa RUE 52 E E E E E E E ae 53 3 2 1 Bit Error Rate BER A bit error rate BER measurement compares the transmitted bits with the determined symbol decision bits BER error bits number of analyzed bits As a prerequisite for this measurement the VSA application must know which bit sequences are correct i e which bit sequences may occur This knowledge must be provided as a list of possible data sequences in xml format which is loaded in the VSA application see chapter 4 9 Known Data Files Dependencies and Restrictions on page 123 Auxiliary tool to create Known Data files An auxiliary tool to create Known Data files from data that is already available in the VSA application is provided on the instrument free of charge See chapter 8 2 3 2 How to Create Known Data Files on page 219 If such a file is loaded in the application the BER result display is available Available for source types Modulation Accuracy R amp S FPS K70 Measurements and Result Displays Note that this measurement may take some time as each symbol decision must be compared to the possible data sequences one by one The BER measurement is an indicator for the quality of the demodulated signal High BER values indicate problems such as inadequate demodulation
513. ting mode additional tabs and elements are available A colored back ground of the screen behind the measurement channel tabs indicates that you are in MSRA operating mode For details on the MSRA operating mode see the R amp S FPS MSRA User Manual Channel bar information In VSA application the R amp S FPS shows the following settings Table 2 1 Information displayed in the channel bar in VSA application Ref Level Reference level Freq Center frequency for the RF signal Std Selected measurement standard or modulation type if no standard selected Res Len Result Length SR Symbol Rate Att Mechanical and electronic RF attenuation Offset Reference level offset Cap Len Capture Length instead of result length for capture buffer display see Capture Length Settings on page 156 Dum mW e eme User Manual 1176 8516 02 06 12 Understanding the Display Information Input Input type of the signal source see chapter 5 5 1 Input Settings on page 142 Burst Burst search active see Enabling Burst Searches on page 165 Pattern Pattern search active see Enabling Pattern Searches on page 167 Stat Count Statistics count for averaging and other statistical operations see Statis tic Count on page 162 cannot be edited directly Capt Count Capture count the current number of captures performed if several cap tures are necessary to obtain the number of results def
514. ting the Reference Level Automatically Auto Level Reference Level Automatically determines the optimal reference level for the current input data At the same time the internal attenuators are adjusted so the signal to noise ratio is opti mized while signal compression clipping and overload conditions are minimized To determine the optimal reference level a level measurement is performed on the R amp S FPS Input Output and Frontend Settings You can change the measurement time for the level measurement if necessary see Changing the Automatic Measurement Time Meastime Manual on page 189 Remote command SENSe ADJust LEVel on page 332 Input Settings Some input settings affect the measured amplitude of the signal as well For information on other input settings see chapter 5 5 1 Input Settings on page 142 Preamplifier option B22 B24 Input Settings Switches the preamplifier on and off If activated the input signal is amplified by 20 dB If option R amp S FPS B22 is installed the preamplifier is only active below 7 GHz If option R amp S FPS B24 is installed the preamplifier is active for all frequencies Remote command INPut GAIN STATe on page 294 Input Coupling Input Settings The RF input of the R amp S FPS can be coupled by alternating current AC or direct cur rent DC AC coupling blocks any DC voltage from the input signal This is the default setting to prevent damage to the ins
515. tion power e g at the filter edges may suffer from less accu rate estimation results Remote commands LAY ADD 1 BEL EQU to define the required source type see LAYout ADD WINDow on page 359 CALC FEED XFR DDEM IRAT to define the channel frequency response result type see CALCulate lt n gt FEED on page 365 CALC FORM MAGN to define the magnitude result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 6 Equalizer on page 377 3 2 4 Constellation Frequency The instantaneous frequency of the source signal without inter symbol interference as an X Y plot only the symbol decision instants are drawn and not connected Available for source types e Meas amp Ref Signal User Manual 1176 8516 02 06 23 R amp S FPS K70 Measurements and Result Displays 1 Const Freq Meas amp Ref 1M Clrw 9 907 MHz Fig 3 2 Result display Constellation Frequency Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM CONF to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 3 Polar Diagrams on page 376 3 2 5 Constellation Th
516. to amplitude settings 9 lt gt lt gt 293 lt gt lt gt 293 rt oue pct Ee et dac tocando read 293 PUUu M O EN 294 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel lt ReferenceLevel gt This command defines the reference level for all traces lt t gt is irrelevant With a reference level offset 0 the value range of the reference level is modified by the offset Parameters lt ReferenceLevel gt The unit is variable Range see datasheet RST 0 dBm Example DISP TRAC Y RLEV 60dBm Usage SCPI confirmed Manual operation See Reference Level on page 148 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel OFFSet Offset This command defines a reference level offset for all traces t is irrelevant Parameters Offset Range 200 dB to 200 dB RST Example DISP TRAC Y RLEV OFFS 10dB Manual operation See Shifting the Display Offset on page 148 SENSe DDEMod PRESet RLEVel This command initiates a measurement that evaluates and sets the ideal reference level for the current measurement This ensures
517. ton The dialog box is closed and the current measurement settings are stored in a standard file To delete standard files 1 In the Meas menu select the Digital Standards softkey 2 Inthe Manage VSA Standards file selection dialog box select the standard whose settings file you want to delete Standards predefined by Rohde amp Schwarz can also be deleted To change the path press the arrow icons at the right end of the Path field and select the required folder from the file system 3 Press the Delete button 4 Confirm the message to avoid unintentionally deleting a standard The standard file is removed from the folder 8 2 How to Perform Customized Measurements To restore standard files 1 restore the predefined standard files do one of the following e Inthe Meas menu select the Digital Standards softkey The Manage VSA Standards file selection dialog box is displayed e Inthe Meas menu select the Restore Factory Settings softkey 2 Select Restore Standard Files The standards predefined by Rohde amp Schwarz available at the time of delivery are restored to the Standards folder How to Perform Customized VSA Measurements In addition to performing vector signal analysis strictly according to specific digital standards you can configure the analysis settings for customized tasks The general process for a typical measurement is described here 1 Press the MODE k
518. tor result display For details see chapter 4 8 Capture Buffer Display on page 122 M 2 2 1 1 User Manual 1176 8516 02 06 53 R amp S9FPS K70 Measurements and Result Displays 3 3 1M Clrw 1 Vector 1 Fig 3 24 Result display for Vector Remote commands LAY ADD 1 B EL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM COMP to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 3 Polar Diagrams on page 376 Common Parameters in VSA Depending on the modulation type you are using different signal parameters are deter mined during vector signal analysis Details concerning the calculation of individual parameters can be found in chapter 4 5 Signal Model Estimation and Modulation Errors on page 100 and chapter A 6 For mulae on page 425 Table 3 4 Parameters for PSK QAM and MSK modulation Parameter Description SCPI Parameter EVM RMS Peak Error Vector Magnitude normalized to mean reference EVM power by default see Normalize EVM to on page 181 MER RMS Peak Modulation Error Ratio SNR Phase Error RMS The phase difference between the measurement vector and PERR Peak the reference vector User Manual 1176 8516 02
519. tory This command restores the factory settings of standards or patterns for the VSA appli cation Setting parameters Factory ALL STANdard PATTern ALL Restores both standards and patterns RST ALL Usage Setting only Digital Standards Manual operation See Restore Standard Files on page 129 See Restore Pattern Files on page 129 SENSe DDEMod PRESet STANdard Standard This command selects an automatic setting of all modulation parameters according to a standardized transmission method or a user defined transmission method The standardized transmission methods are available in the instrument as predefined standards Setting parameters Standard string Specifies the file name that contains the transmission method without the extension For user defined standards the file path must be included Default standards predefined by Rohde amp Schwarz do not require a path definition A list of prede fined standards including short forms is provided in the annex see chapter A 2 Predefined Standards and Settings on page 412 Example DDEM PRES TETRA NDDOWN Switches the predefined digital standard TETRA Disconti nuousDownlink on DDEM PRES C R_S Instr usr standards USER_GSM Switches the user defined digital standard USER GSM on Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Manual ope
520. trument Very low frequencies in the input signal may be dis torted However some specifications require DC coupling In this case you must protect the instrument from damaging DC input voltages manually For details refer to the data sheet Remote command INPut COUPling on 288 RF Attenuation Defines the mechanical attenuation for RF input Attenuation Mode Value RF Attenuation The RF attenuation can be set automatically as a function of the selected reference level Auto mode This ensures that the optimum RF attenuation is always used It is the default setting By default and when Using Electronic Attenuation is not available mechanical attenua tion is applied In Manual mode you can set the RF attenuation in 1 dB steps down to 0 dB Other entries are rounded to the next integer value The range is specified in the data sheet If the defined reference level cannot be set for the defined RF attenuation the refer ence level is adjusted accordingly and the warning Limit reached is displayed Input Output and Frontend Settings NOTICE Risk of hardware damage due to high power levels When decreasing the attenuation manually ensure that the power level does not exceed the maximum level allowed at the RF input as an overload may lead to hardware damage Remote command INPut ATTenuation on page 294 INPut ATTenuation AUTO on page 295 Using Electronic Attenuation If the optional Electronic Atte
521. ts of the offset measurement performed for digital demodulation Query parameters type none Origin offset error for current sweep Average origin offset error over several sweeps RPE Peak origin offset error over several sweeps SDEV Standard deviation of origin offset error PCTL 95 percentile value of origin offset error Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic PERRor type This command queries the results of the phase error measurement performed for digi tal demodulation Retrieving Results Query parameters type none RMS phase error of display points of current sweep AVG Average of RMS phase errors over several sweeps PAVG Average of maximum phase errors over several sweeps PCTL 9596 percentile of RMS phase error over several sweeps PEAK Maximum EVM over all symbols of current sweep PPCT 95 percentile of maximum phase errors over several sweeps PSD Standard deviation of maximum phase errors over several Sweeps RPE Maximum value of RMS EVM over several sweeps SDEV Standard deviation of phase errors over several sweeps TPE Maximum EVM over all display points over several sweeps Usage Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic QERRor type This command queries the results of the Quadratur error measurement performed for digital demodulation Query parameters type none quadrature error for c
522. ts the result range from the capture buffer that you want to evaluate This function is available in single sweep mode only By default the application shows the results over all result ranges that have been cap tured in the signal capturing process and are in the R amp S FPS s memory By selecting a range number you can evaluate a specific result range e g a particular burst The range depends on the number of result ranges you have captured previously For more information refer also to chapter 4 6 Measurement Ranges on page 116 Remote command SENSe DDEMod SEARch MBURSt CALC on page 307 Refresh This function is only available if the Sequencer is deactivated and only for MSRA applications The data in the capture buffer is re evaluated by the currently active application only The results for any other applications remain unchanged This is useful for example after evaluation changes have been made or if a new sweep was performed from another application in this case only that application is updated automatically after data acquisition 5 7 5 7 1 Burst and Pattern Configuration Note To update all active applications at once use the Refresh all function in the Sequencer menu Remote command INITiate lt n gt REFResh on 335 Burst and Pattern Configuration Information on known patterns and bursts in the captured signal improve the accuracy of the determined ideal reference si
523. ue for the current peak or mean EVM peak or RMS limit Note that the limits for the current and the peak value are always kept identical Setting parameters lt LimitValue gt numeric value Range 0 0 to 100 RST 1 5 Default unit CALCulate lt n gt LIMit MACCuracy FDERror CURRent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy FDERror MEAN VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy FDERror PEAK VALue lt LimitValue gt This command defines the lower limit for the current peak or mean center frequency deviation error Note that the limits for the current and the peak value are always kept identical This command is available for FSK modulation only Setting parameters lt LimitValue gt numeric value Range 0 0 to 1000000 RST 1 kHz Default unit Hz CALCulate lt n gt LIMit MACCuracy FERRor PCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy FERRor PMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy FERRor PPEak VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy FERRor RCURrent VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy FERRor RMEan VALue lt LimitValue gt CALCulate lt n gt LIMit MACCuracy FERRor RPEak VALue lt LimitValue gt This command defines the value for the current peak or mean frequency error peak or RMS limit Note that the limits for the current and the peak value are always kept identical This command is availabl
524. uency The eye diagram of the currently measured frequencies and or the reference signal The time span of the data depends on the evaluation range capture buffer Available for source types e Meas amp Ref Signal Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM FEYE User Manual 1176 8516 02 06 27 R amp S9FPS K70 Measurements and Result Displays 3 2 9 to define the result type see CALCulate lt n gt FORMat on 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 Eye Diagram Imag Q The eye pattern of the quadrature channel the x axis range is from 1 to 1 sym bols MSK 2 to 2 Available for source types e Meas amp Ref Signal 2 Eye O Meas amp Ref iM Clrw Fig 3 6 Result display Eye Diagram Imag Q Remote commands LAY ADD 1 BEL MEAS to define the required source type see LAYout ADD WINDow page 359 CALC FORM QEYE to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to query the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 User Manual 1176 8516 02 06 28 R amp S9FPS K70 Measurements and Result Dis
525. uency Error Absolute Displays the error of the instantaneous frequency in Hz of the measurement signal with respect to the reference signal as a function of symbols over time FREQ ERR s FREQprr t with tzn Tp and duration of one sampling period at the sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 Note that this measurement does not consider a possible carrier frequency offset This has already been compensated for in the measurement signal This measurement is mainly of interest when using the MSK or FSK modulation but o can also be used for the PSK QAM modulations However since these modulations can have transitions through zero in the plane in this case you might notice uncriti cal spikes This is due to the fact that the phase of zero or a complex value close to zero has in fact limited significance but still influences the result of the current fre quency measurement R amp S9FPS K70 Measurements and Result Displays 3 2 14 1Freq Error Abs 349 sym Fig 3 10 Result display Frequency Error Absolute Available for source types e Modulation Errors Remote commands LAY ADD 1 BEL MERR to define the required source type see LAYout ADD WINDow 2 page 359 CALC FORM FREQ to define the result type see CALCulate lt n gt FORMat on page 366 TRAC DATA 1 to q
526. uery the trace results see TRACe lt n gt DATA TRACE lt n gt and chapter 11 9 2 2 Cartesian Diagrams on page 376 Frequency Error Relative Displays the error of the instantaneous frequency of the measurement signal with respect to the reference signal as a function of symbols over time The results are normalized to the symbol rate PSK and QAM modulated signals the estimated FSK deviation FSK modulated signals or one quarter of the symbol rate MSK modulated signals FREQ _ ERR FREQw Eas t with tzn and Tp the duration of one sampling period at sample rate defined by the display points per symbol parameter see Display Points Sym on page 203 E User Manual 1176 8516 02 06 33 R amp S FPS K70 Measurements and Result Displays can also be used for the PSK QAM modulations See also the note for chapter 3 2 13 o This measurement is mainly of interest when using the MSK or FSK modulation but Frequency Error Absolute on page 32 1 49 sym Fig 3 11 Result display Frequency Error Relative Available for source types e Modulation Errors Remote commands LAY ADD 1 BEL MERR to define the required source type see LAYout ADD WINDow page 359 CALC FORM FREQ to define the result type see CALCulate lt n gt FORMat on page 366 DISP TRAC Y MODE REL to define relative values see DISPlay
527. ult types are available chapter 3 2 29 Result Summary on page 47 chapter 3 2 1 Bit Error Rate BER on page 20 The results of a modulation accuracy measurement can be checked for violation of defined limits automatically If limit check is activated and the measured values exceed the limits those values are indicated in red in the result summary table If limit check is activated and no values exceed the limits the checked values are indicated in green 1 Result Summary Current EVM RMS Peak MER RMS 18 00 Peak 0 28 Phase Error RMS 6 62 Peak 44 67 Magnitude Error RMS Peak 48 74 Carrier Frequency Error 201 04 Rho 0 984 404 I Q Offset 40 15 170 Imbalance 57 56 Gain Imbalance 0 01 Quadrature Error 0 14 Amplitude Droop 0 000 53 Remote command LAY ADD 1 BEL MACC see LAYout ADD WINDow on page 359 Equalizer Filter characteristics of the equalizer used to compensate for channel distortion and parameters of the distortion itself The following result types are available chapter 3 2 18 Impulse Response Magnitude on page 37 chapter 3 2 19 Impulse Response Phase on page 38 chapter 3 2 20 Impulse Response Real Imag on page 38 chapter 3 2 16 Frequency Response Magnitude on page 35 chapter 3 2 17 Frequency Response Phase on page 36 chapter 3 2 15 Frequency Response Group Delay on page 34 chapter 3 2 3 Channel Frequency Response Magnitude on page 22 chapter 3 2 2 Ch
528. ulti channel signals all chan nels have the same number of samples One sample can be e complex number represented as a pair of and values e complex number represented as a pair of magnitude and phase values Areal number represented as a single real value See also Format element Contains the clock frequency in Hz i e the sample rate of the data A signal gen erator typically outputs the I Q data at a rate that equals the clock frequency If the data was captured with a signal analyzer the signal analyzer used the clock fre quency as the sample rate The attribute unit must be set to Hz Format Specifies how the binary data is saved in the data binary file see DataFilename element Every sample must be in the same format The format can be one of the following complex Complex number in cartesian format i e and Q values interleaved 1 and Q are unitless real Real number unitless polar Complex number in polar format i e magnitude unitless and phase rad values interleaved Requires DataType float32 or f1oat64 DataType Specifies the binary format used for samples in the data binary file see DataFilename element and chapter A 7 2 Data Binary File on page 443 The following data types are allowed int8 8 bit signed integer data int16 16 bit signed integer data int32 32 bit signed integer data float32 32 bit floating point data IEEE 754 float
529. umber of permitted states depends on the modulation mode Setting parameters lt NState gt numeric value Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Manual operation See Mod order on page 173 Configuring VSA SENSe DDEMod SEARch SYNC PATTern ADD lt AddPattern gt This command adds a pattern to the current standard Using the DDEM SEAR SYNC SEL command only those patterns can be selected which belong to the current standard see SENSe DDEMod SEARch SYNC SELect on page 312 Setting parameters lt AddPattern gt string Example See chapter 11 13 3 Measurement Example 3 User Defined Pattern Search and Limit Check on page 409 Usage Setting only Manual operation See Adding patterns to a standard on page 170 SENSe DDEMod SEARch SYNC PATTern REMove This command deletes one or all patterns from the current standard Usage Setting only Manual operation See Removing patterns from a standard on page 170 SENSe DDEMod SEARch SYNC TEXT lt Text gt This command defines a text to explain the pattern The text is displayed only in the selection menu manual control This text should be short and concise Detailed infor mation about the pattern is given in the comment see SENSe DDEMod SEARch SYNC COMMent on page 312 Setting parameters Text string Example See c
530. ument A file selection dialog box is displayed in which you can select the storage loca tion and file name You can also add an optional comment to the file e Otherwise reset the tool to start a new recording possibly after changing the demodulation settings or input data 7 Close the tool window to return to normal operation of the VSA application The created xml file can now be loaded in the VSA application as described in chap ter 8 2 3 1 How to Load Known Data Files on page 218 8 2 4 How to Define the Result Range You can define which part of the source signal is analyzed Result Range with refer ence to the captured data a detected burst or a detected pattern For details on the functions see chapter 5 8 Result Range Configuration on page 173 1 In the Overview select Range Settings 2 Select the Result Range tab 3 Define the Result Length i e the number of symbols from the result that are to be analyzed Note that when you use Known Data files as a reference the Result Length specified here must be identical to the length of the specified symbol sequences in the xml file lt ResultLength gt element See chapter 4 9 Known Data Files Dependencies and Restrictions on page 123 4 Define the Reference for the result range i e the source to which the result will be aligned The reference can be the captured data a detected burst or a detected pattern How to Analyze the Measure
531. urement filter specified by SENSe DDEMod MFILter NAME on However this command is not necessary as the SENSe DDEMod MFILter NAME com mand automatically switches the selected filter on RST 1 Manual operation See Type on page 186 SENSe DDEMod MFILter USER lt FilterName gt This command selects the user defined measurement filter For details on user defined filters see chapter 4 1 5 Customized Filters on page 61 Setting parameters lt FilterName gt Name of the user defined filter Example SENS DDEM MFIL NAME USER Selects user filter mode for the meas filter ENS DDEM MFIL USER D MMyMeasFilter Selects the user defined meas filter Manual operation See Type on page 186 See Load User Filter on page 186 Defining the Evaluation Range The evaluation range defines which range of the result is to be evaluated Manual configuration of the evaluation range is described in chapter 5 11 Evaluation Range Configuration on page 187 GALCulate n EkINsstartstops S TATe eter toc Eon e ARR EE 328 CALOCulate n ELIN startstop VALue esses nnne rens 329 CALCulate lt n gt ELIN lt startstop gt STATe Auto This command restricts the evaluation range The evaluation range is considered for the following display types eye diagrams constellation diagrams modulation accuracy e statistic displays
532. urn values lt NewWindowName gt When adding a new window the command returns its name by default the same as its number as a result Example LAY ADD WIND 1 RIGH SYMB Adds a Symbol Table display to the right of window 1 Usage Manual operation Configuring the Result Display Query only See Capture Buffer on page 15 See Measurement amp Reference Signal on page 15 See Symbols on page 16 See Error Vector on page 16 See Modulation Errors on page 16 See Modulation Accuracy on page 17 See Equalizer on page 17 See Signal Source on page 202 For a detailed example see chapter 11 13 1 Measurement Example 1 User defined Measurement of Continuous QPSK Signal on page 404 Table 11 2 WindowType parameter values for VSA application Parameter value Data source default result display CBUFfer Capture buffer Magnitude absolute MEAS Meas amp Ref Magnitude relative REF EQualizer Equalizer EVECtor Error vector EVM MACCuracy Modulation Accuracy Result Summary MERRor Modulation Errors Magnitude error SYMB Symbols Hexadecimal LAYout CATalog WINDow This command queries the name and index of all active windows in the active mea surement channel from top left to bottom right The result is a comma separated list of values for each window with the syntax lt WindowName_1 gt lt Windowlndex_1 gt lt WindowName_n gt lt Windowlndex_n gt
533. urrent sweep AVG Average quadrature error over several sweeps RPE Peak quadrature error over several sweeps SDEV Standard deviation of quadrature error PCTL 95 percentile value of quadrature error Usage Query only Retrieving Results CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic RHO type This command queries the results of the Rho factor measurement performed for digital demodulation Query parameters type Usage lt none gt Rho factor for current sweep AVG Average rho factor over several sweeps RPE Peak rho factor over several sweeps SDEV Standard deviation of rho factor PCTL 95 percentile value of rho factor Query only CALCulate lt n gt MARKer lt m gt FUNCtion DDEMod STATistic SNR lt type gt This command queries the results of the SNR error measurement performed for digital demodulation Query parameters lt type gt Usage lt none gt RMS SNR value of display points of current sweep AVG Average of RMS SNR values over several sweeps PAVG Average of maximum SNR values over several sweeps PCTL 95 percentile of RMS SNR value over several sweeps PEAK Maximum EVM over all symbols of current sweep PPCT 95 percentile of maximum SNR values over several sweeps PSD Standard deviation of maximum SNR values over several sweeps RPE Maximum value of RMS EVM over several sweeps SDEV Standard deviation of SNR values over several sweeps TPE Maxi
534. us frequency see chapter 4 5 2 1 Error Model on page 112 There fore the measurement value that corresponds to the EVM value for FSK is the the Fre quency Error Absolute Relative Source Type Modulation Error Result Type Fre quency Error Absolute Relative 10 4 Obtaining Technical Support If problems occur the instrument generates error messages which in most cases will be sufficient for you to detect the cause of an error and find a remedy Error messages are described in chapter 10 2 Explanation of Error Messages on page 246 In addition our customer support centers are there to assist you in solving any prob lems that you may encounter with your R amp S FPS We will find solutions more quickly and efficiently if you provide us with the information listed below System Configuration The System Configuration dialog box in the Setup menu of the soft front panel provides information on Hardware Info hardware assemblies Versions and Options the status of all software and hardware options instal led on your instrument System Messages messages on any errors that may have occurred An xml file with information on the system configuration device footprint can be created automatically using the DIAGnostic SERVice SINFo command or as described in To collect the support information on page 263 Error Log The RSError 10g in the log directory of the main installation director
535. used Averaging The results of the equalizer in all previous sweeps since the instru ment was switched on or the equalizer was reset are considered to calculate the new filter To start a new averaging process select the Reset Equalizer button Calculation of the equalizer requires addi tional processing time Remote command SENSe DDEMod EQUalizer MODE on page 321 Filter Length Equalizer Settings Defines the length of the equalizer in symbols The longer the equalizer the more accurate the filter becomes and the more distortion can be compensated However this requires extended calculation time The shorter the filter length the less calculation time is required during the equalizer s tracking or averaging phase Remote command SENSe DDEMod EQUalizer LENGth on page 320 Reset Equalizer Equalizer Settings Deletes the data of the currently selected equalizer After deletion averaging and tracking starts anew This is useful in the rare case that calculation takes a wrong symbol decision into con sideration and distorts the signal such that the original signal can no longer be deter mined Remote command SENSe DDEMod EQUalizer RESet on page 322 Store Load Current Equalizer Equalizer Settings Saves the current equalizer results to a file or loads a user defined equalizer The equalizer Mode must be set to USER in order to load a file Remote command SE
536. ustomizing the screen layout or configuring networks and remote operation Using the common status registers The following tasks specific to are described here 6 uere mE 264 Como ARE eo roter eb rude erent 269 e Activating Vector Signal 269 Digital Sta AN 273 Configuiiing E 275 Performing MSsasureimbl 3 ert S e 332 NY MT 338 e Configuring the Result Display ctt tert d eti tet td 357 e Retrieving Resulls etr eee xk Ren KEYS 370 e Importing and Exporting Data and Results sss 390 e Status Reporting t ent ed ebd d 391 e Commands for Compatbility 2 ciere teet cire eta 402 Frogramiming EXatmples rper uet Ep EE RE 403 Introduction Commands are program messages that a controller e g a PC sends to the instru ment or software They operate its functions setting commands 5 and request information query commands Some commands can only be used in one way others work in two ways setting and query If not indicated otherwise the com mands can be used for settings and queries The syntax of a SCPI command consists of a header and in most cases one or more parameters To use a command as a query you have to append a question mark afte
537. ut The maximum record length that is the maximum number of samples that can be cap tured depends on the sample rate Sample Rate Symbol Rate and Bandwidth Table 4 2 Maximum record length Sample rate Maximum record length 100 Hz to 200 MHz 440 MSamples precisely 461373440 440 1024 1024 samples 200 MHz to 10 GHz 220 MSamples upsampling The figure 4 6 shows the maximum usable bandwidths depending on the output sample rates Usable bandwidth Q bandwidths for RF input 160 MHz Activated option B160 11111117 130 VA 0020 PAE T 50 esses sese LLLLLLLLLLLLLLLLL ess LI penso options Output sample 10000 rate fou MHz 100 20 40 60 80 100 120 140 160 180 200 Fig 4 6 Relationship between maximum usable bandwidth and output sample rate with and with out bandwidth extensions 4 2 1 4 R amp S FPS without additional bandwidth extension options sample rate 100 Hz 10 GHz maximum bandwidth 28 MHz 4 2 1 5 4 2 1 6 Symbol Mapping Sample rate Maximum bandwidth 100 Hz to 35 MHz proportional up to maximum 28 MHz 35 MHz to 10 GHz 28 MHz R amp S FPS with option B40 I Q Bandwidth Extension sample rate 100 Hz 10 GHz maximum bandwidth 40 MHz Sample rate Maximum bandwidth
538. utputs the measured value of marker 2 Usage Query only DISPlay WINDow lt n gt TRACe lt t gt X SCALe STARt This command queries the first value of the x axis in the specified window in symbols or time depending on the unit setting for the x axis Note using the CALCulate lt n gt TRACe lt t gt ADJust ALIGnment OFFSet com mand the burst is shifted in the diagram the x axis thus no longer begins on the left at 0 symbols but at a selectable value Example See chapter 11 13 2 Measurement Example 2 GSM EDGE Burst Measurement Based on a Digital Standard on page 405 Usage Query only DISPlay WINDow lt n gt TRACe lt t gt X SCALe STOP This command queries the last value of the x axis in the specified window in symbols or time depending on the unit setting for the x axis Note If the burst is shifted using the CALC TRAC ALIG commands the x axis no lon ger begins at 0 symbols on the left but at a user defined value Example CALC TRAC ADJ BURS Defines the burst as the reference for the screen display CALC TRAC ADJ ALIG CENT Position the burst at the center of the screen DISP TRAC X STOP Queries the stop value of the x axis Retrieving Results Usage Query only FORMat DEXPort DSEParator lt Separator gt This command selects the decimal separator for data exported in ASCII format Parameters lt Separator gt COMMa Uses a comma as decimal separator e g 4 05 POINt Uses a p
539. value the modulation settings see Alpha BT on page 138 Remote command Measurement filter SENSe DDEMod MFILter ALPHa on page 327 Transmit filter SENSe DDEMod TFILter ALPHa page 283 Evaluation Range Configuration The evaluation range defines which range of the result is to be evaluated either the entire result range or only a specified part of it The calculated length of the specified range is indicated beneath the entries A visualization of the evaluation range in relation to the result range with the current settings is displayed at the bottom of the dialog box The green bar below the trace indicates the defined result range indented red lines indicate defined start and stop symbols see Evaluation range display on page 120 The visualization is not editable directly The Evaluation Range settings are displayed when you do one of the following e Select the Evaluation Range button from the Overview e Select the Range Settings softkey from the main VSA menu Then switch to the Evaluation Range tab Result Range Evaluation Range Evaluation Range Entire Result Range 0 sym 148 sym Start 3 0 sym Stop 144 75 sym Length 142 0 sym 524 308 ps Visualization Adjusting Settings Automatically For details on the evaluation range see chapter 4 6 Measurement Ranges on page 116 For an example on setting the evaluation range see chapter 9 3 5 Setting the Evalua
540. viation FSK only on page 137 CALCulate lt n gt FSK DEViation REFerence VALue lt FSKRefDevAbsRes gt This command defines the deviation to the reference frequency for FSK modulation as an absolute value in Hz Setting parameters lt FSKRefDevAbsRes gt numeric value Range 10 0 to 64e9 RST 100e3 Default unit Hz Manual operation See FSK Ref Deviation FSK only on page 137 SENSe DDEMod APSK NSTate lt APSKNstate gt This command defines the specific demodulation mode for APSK The following APSK demodulation modes are possible DDEMod APSK NSTate 16 16APSK 32 32APSK Setting parameters lt APSKNstate gt numeric value RST 16 Manual operation See Modulation Order on page 136 SENSe DDEMod ASK NSTate lt ASKNstate gt This command defines the specific demodulation mode for ASK The following ASK demodulation modes are possible DDEMod ASK NSTate 2 OOK 4 4ASK Setting parameters lt ASKNstate gt numeric value RST 2 Manual operation See Modulation Order on page 136 SENSe DDEMod FILTer ALPHa lt MeasFiltAlphaBT gt This command determines the filter characteristic ALPHA BT The resolution is 0 01 Setting parameters lt MeasFiltAlphaBT gt Configuring VSA numeric value Range 0 1 to 1 0 RST 0 22 Default unit NONE SENSe DDEMod FILTer STATe lt MeasFilterState gt This command defines whether the input signal that is evaluated is filtered by the mea surement filter
541. view for VSA 6 Select the Signal Description button and configure the expected signal character istics a In the Modulation Settings section ensure that the Type is PSK and that the Order is QPSK The Mapping defines the mapping of the bits to the QPSK symbols It is relevant if you are interested in a bit stream measurement but does not affect the other measurement results Hence you do not need to change it here b Enter the Symbol Rate 1 MHz R amp S FPS K70 Measurement Examples c Inthe Transmit Filter section select RRC as Type and enter the Alpha BT value 0 35 In the preview area of the dialog you should then see a non distorted QPSK constellation diagram as shown in figure 9 2 De Modulation Signal Structure Known Data Modulation Settings Type Order Mapping Symbol Rate Transmit Filter Type Alpha BT Preview Const I Q Meas amp Ref 1M Clrw Fig 9 2 QPSK signal with RRC transmit filter 7 Close all open dialog boxes By default four measurement windows showing differ ent measurement results are displayed User Manual 1176 8516 02 06 231 R amp S FPS K70 Measurement Examples Spectrum VSA Ref Level 4 00 dBm Mod QPSK SR 1 0 MHz m el Att 20 4 08 Freq 1 0GHz ResLen 800 A Const I Q Meas amp Ref 1M Clrw B Result Summary Phase Err RM Carrier Freq Err Gain Imbalance Quadrature Err Amplitude Droop Start 2 43 Stop 2 43 C Mag CapBuf
542. w the data in a web browser 1 Use an archive tool e g WinZip or PowerArchiver to unpack the ig tar file into a folder Locate the folder using Windows Explorer Open your web browser Drag the parameter XML file e g example xml into your web browser 41 De Saved by FSV 10 Analyzer Comment Here is a comment Date amp Time 2011 03 03 14 33 05 Sample rate 6 5 MHz Number of samples 65000 Duration of signal 10 ms Data format complex float32 Data filename Scaling factor 1v eh Comment Channel 1 of 1 Power vs time y axis 10 dB div x axis 1 ms div Spectrum y axis 20 dB div x axis 500 kHz div E mail info rohde schwar Fileformat version 1 z com Internet http Aeww rohde schwarz com How to Perform VSA According to Digital Standards 8 How to Perform Vector Signal Analysis Using the VSA option you can perform vector signal analysis measurements using pre defined standard setting files or independently of digital standards using user defined measurement settings Such settings can be stored for recurrent use Thus configuring measurements requires one of the following tasks e Selecting an existing standard settings file and if necessary adapting the mea surement settings
543. xecuted the Sequencer must be activated see SYSTem SEQuencer on page 337 Suffix lt n gt irrelevant Example SYST SEQ ON Activates the Sequencer INIT SEQ MODE SING Sets single sequence mode so each active measurement will be performed once INIT SEQ IMM Starts the sequential measurements Usage Event INITiate lt n gt SEQuencer MODE lt Mode gt This command selects the way the R amp S FPS application performs measurements sequentially Before this command can be executed the Sequencer must be activated see SYSTem SEQuencer on page 337 A detailed programming example is provided in the Operating Modes chapter in the R amp S FPS User Manual Note In order to synchronize to the end of a sequential measurement using OPC OPC or WAI you must use SING1e Sequence mode For details on synchronization see the Remote Basics chapter in the R amp S FPS User Manual Suffix n irrelevant Performing a Measurement Parameters Mode SINGIe Each measurement is performed once regardless of the chan nel s sweep mode considering each channels sweep count until all measurements in all active channels have been per formed CONTinuous The measurements in each active channel are performed one after the other repeatedly regardless of the channel s sweep mode in the same order until the Sequencer is stopped CDEFined First a single sequence is performed Then only those cha
544. y contains a chronological record of errors Obtaining Technical Support Support file a zip file with important support information can be created auto matically The zip file contains the system configuration information device foot print the current eeprom data and a screenshot of the screen display To collect the support information 1 Select the SETUP key in the soft front panel on the Remote Desktop 2 Select Service gt R amp S Support and then Create R amp S Support Information The file is stored as C R_S instr user service zip Attach the support file to an e mail in which you describe the problem and send it to the customer support address for your region as listed in the Internet http www rohde schwarz com en service support customer support 107711 11 11 1 Introduction Remote Commands for VSA The following commands are required to perform measurements in VSA in a remote environment It is assumed that the R amp S FPS has already been set up for remote control in a net work as described in the R amp S FPS User Manual Note that basic tasks that are also performed in the base unit in the same way are not described here For a description of such tasks see the R amp S FPS User Manual In particular this includes Managing Settings and Results i e storing and loading settings and result data Basic instrument configuration e g checking the system configuration c
545. y quickly by selecting the appropriate button Function Trace Settings Preset All Traces Trace 1 Clear Write Traces 2 6 Blank Set Trace Mode Trace 1 Max Hold Max Avg Min Trace 2 Average Trace 3 Min Hold Traces 4 6 Blank Set Trace Mode Trace 1 Max Hold Min 2 Clear Write Trace 3 Min Hold Traces 4 6 Blank Trace 1 2 Trace 3 Trace 4 Softkeys Displays the Traces settings and focuses the Mode list for the selected trace Remote command DISPlay WINDowcn TRACe t STATe on page 340 R amp S9FPS K70 Analysis 6 2 Trace Export Settings The captured trace data can also be exported to an ASCII file The format of these files can be configured Traces Std 3G WCDMA SR 3 84 MHz mm Traces Trace Export Mode Header Decimal Seperator Point Export Trace to ASCII File for all Windows Export Trace to ASCII File for Specific Window 75 1 Constellation I Q Meas amp Ref Data Gs E 193 Heada onsa 193 SR 194 ASO EXPO D 194 Data Export Mode Defines whether raw data as captured trace data evaluated is stored Remote command FORMat DEXPort MODE on page 373 Header I
546. y analyze data that is contained in the capture buffer Range 0 to lt Record length gt RST 0 Manual operation See Capture Offset on page 161 11 7 5 Zooming into the Display 11 7 51 Using the Single Zoom bISPlayWINDewensrZOONE AREA rua in oti tr Re euo tre eene 356 cited o to ta ett 356 R amp S9FPS K70 Remote Commands for VSA 11 7 5 2 DISPlay WINDow lt n gt ZOOM AREA lt 1 gt lt 1 gt lt 2 gt lt 2 gt This command defines the zoom area To define a zoom area you first have to turn the zoom on 1 Frequency Sweep iRm Span 25 0 MHz CF 2 000519931 GHz 498 pts 1 24 2 12 435008666 MHz 1 origin of coordinate system x1 0 y1 0 2 end point of system x2 100 y2 100 3 zoom area e g x1 60 y1 30 x2 80 y2 75 Parameters lt x1 gt lt y1 gt Diagram coordinates in of the complete diagram that define lt 2 gt lt 2 gt the zoom area The lower left corner is the origin of coordinate system The upper right corner is the end point of the system Range 0 to 100 Default unit PCT Manual operation See Single Zoom on page 205 DISPlay WINDow lt n gt ZOOM STATe State This command turns the zoom on and off Parameters State OFF RST OFF Example DISP ZOOM ON Activates the zoom mode Manual operation See Single Zoom on page 205 See R
547. y set to a user defined value Auto The step size is set to the default value e using the rotary knob 100 kHz using the arrow keys 1 MHz Manual Defines a user defined step size for the center frequency Enter the step size in the Value field Remote command SENSe FREQuency CENTer STEP AUTO on page 292 SENSe FREQuency CENTer STEP on page 291 5 5 4 5 5 4 1 Input Output and Frontend Settings Frequency Offset Shifts the displayed frequency range along the x axis by the defined offset This parameter has no effect on the instrument s hardware or on the captured data or on data processing It is simply a manipulation of the final results in which absolute fre quency values are displayed Thus the x axis of a spectrum display is shifted by a constant offset if it shows absolute frequencies but not if it shows frequencies relative to the signal s center frequency A frequency offset can be used to correct the display of a signal that is slightly distorted by the measurement setup for example The allowed values range from 100 GHz to 100 GHz The default setting is 0 Hz Note In MSRA mode this function is only available for the MSRA Master Remote command SENSe FREQuency OFFSet on page 292 Amplitude and Vertical Axis Configuration Amplitude and scaling settings allow you to configure the vertical y axis display and for some result displays also the horizontal x axis e
548. ymbol number 10 as the result range start Defining the evaluation range CALC ELIN STAT ON CALC ELIN1 10 CALC ELIN2 190 Evaluation range starts at symbol 10 and ends at symbol 190 LAY WIND4 REM Close symbol table display window 4 DISPlay WINDow1 TRACe2 MODE Add a second trace in max hold mode to EVM vs Time display window 1 LAY ADD 3 RIGH MEAS Create new window to the right of capture buffer window 3 with measurement signal as data type Result 4 CALC4 FORM MAGN Set result type for window 4 to magnitude DISPlay WINDow4 TRACe2 MODE WRIT CALC4 TRAC2 REF Add second trace in clear write mode for the reference signal CALC LIM MACC STAT ON Activates limit checks for all values in the Result Summary INIT CONT OFF Select single sweep mode INIT WAI Initiate a new measurement and wait until the 10 sweeps have finished Programming Examples CALC2 MARK FUNC DDEM STAT EVM AVG CALC LIM MACC EVM RCUR Query the value and check the limit for the EVM RMS value in the result summary for the current evaluation range Result CALC2 MARK FUNC DDEM STAT EVM PAVG CALC LIM MACC EVM PPE Query the value and check the limit for the largest error vector magnitude in the measurement Result CALC2 MARK FUNC DDEM STAT CFER AVG CALC LIM MACC CFER MEAN Query the value and check the limit for the mean carrier frequency offse
549. you load a Known Data file the R amp S FPS K70 application checks whether the file complies with the following syntax Table 1 6 Known Data File Syntax Syntax Possible Values Description RS VSA KNOWN DATA FILE as specified File Header Version 01 00 gt lt Comment gt lt Comment gt arbitrary Optional file description lt Base gt lt Base gt 2116 The base used to specify the Data values binary hexa decimal For lt ModulationOrder gt values 232 use binary 2 lt ModulationOrder gt lt Modulation Order gt 256 2 4 8 16 32 64 128 Number of values each symbol can represent order of modu lation e g 8 for 8 PSK For lt ModulationOrder gt values 232 use lt Base gt 2 the exact number also depends on available memory space Known Data File Syntax Description Syntax lt ResultLength gt lt ResultLength gt Possible Values 1 up to 2000 Description Number of symbols in each Data element The number must be identical to the Result Length setting in the Result Range dialog box i e the number of symbols to be demodulated Data Data One character per symbol in the sequence Possible characters are 010 n 1 where is the lt ModulationOrder gt Spaces tabs and line breaks are ignored One possible sequence of symbols that can be demodulated from the input signal Up to 6000 different sequ

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