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R&S FSW WLAN Application User Manual

1. Window types for RF data Parameter value Window type AMEV AM EVM IEEE 802 11a g OFDM ac n p only AMPM AM PM IEEE 802 11a g OFDM ac n p only BITStream Bitstream CMEMory Magnitude Capture CONStellation Constellation CV Carrier Constellation vs Carrier IEEE 802 11a g OFDM ac n p only EVCarrier EVM vs Carrier IEEE 802 11a g OFDM ac n p only EVCHip EVM vs Chip IEEE 802 11b and g DSSS only EVSYmbol EVM vs Symbol IEEE 802 11a g OFDM ac n p only FEVPreamble Frequency Error vs Preamble FSPectrum FFT Spectrum GDELay Group Delay IEEE 802 11a g OFDM ac n p only PEVPreamble Phase Error vs Preamble PFALling PvT Falling Edge PFPPdu PvT Full PPDU PRISing PvT Rising Edge RSDetailed Result Summary Detailed IEEE 802 11a g OFDM ac n p only RSGLobal Result Summary Global SFleld Signal Field IEEE 802 11a g OFDM ac n p PLCP Header IEEE 802 11b and g DSSS SFLatness Spectrum Flatness IEEE 802 11a g OFDM ac n p only DIAGram Diagram SEM ACLR MTABle Marker table SEM ACLR PEAKIist Marker peak list SEM ACLR RSUMmary Result summary SEM ACLR LAYout CATalog WINDow This command queries the name and index of all active windows from top left to bot tom right The result is a comma separated list of values for each window with the syn tax lt WindowName_1 gt lt Windowlndex_1 gt lt WindowName_n gt
2. urewop suenba ay ui eunjonags joquiAs WGHO NYTM L 0L aigpl Retrieving Results 96 Zz uonenbe zLOZ YoseW 1 2Q 9811 Z208d 3331 9 g6 ZZ uonenbe zLOZ YJE 120 0981 1Z208d 3331 s v6 Zz uonenbe ZLOZ YEW 120 0981 1 Z208d 3331 p 6S 0Z uonenbe zLOZ 11 Z08 PIS 3331 SIOWEOQNS jolld 0101 E ZZ UONDES ZLOZ YEW 120 981 1 Z08d 3331 Z SISLUE9QNS jolld OL LL E 0Z uonoes ZLOZ 11 Z08 PIS 3331 1 o 6zL KE 2 T dd LEZ EOZ 291 EL LLL uoo pejejo1 Butuul s zz ajqe ez 68 es GZ GZ Ce 68 LLL ZLOZ U S L Z0 9eL1 Z08d 3331 LL LOS 6ZL UL F t 6EL L9L 0z 1ez QL 99r ZLS 091 sjue s u09 pejejoJ Butuur G zz e ge p 1801 S4 ZLOZ YEW 120 981 1 Z08d 3331 LL GHZ s 0 13 Cl Ze 6 LL LL 6e 87 EOL 9 vez E 08 dSN dSy NN 194 os ny 1189 p sny 1SN 9S 1esqns IER 9s Jo os jo id 9s ejep 144g PSN JO ON ny Jo op ON JO ON JO ON ZHN pulp jueuiuio2 SEN PSN 12 INN SN os 1euu1e2qns jot ZEN HEN H n M99 ues 10 9 4 1 10 9 4 2 10 9 4 3 10 9 4 4 Retrieving Results ME cc 283 AN sume H 283 o ud EE 283 Ce GE 283 e CCDF Complementary Cumulative Distribution Funchon 284 Constellation isis io aida 285 e Gonstellation Vs Cane EE 285 e EVM VS IX
3. tested 277 TRAGCeE SAS DATA qm 279 TRIGger SEQuence LEVel POWer AUTO we TRiIGgerf SEQuence BBPower HOLDS cio A TRIGO SEQUENCE TD MR TRIGger SEQuence HOLDOoff TIME orti iaiia aras TRIGger SEQuence 1FPower HOLDJOfT trt rentrer a Ex EEN TRIGger SEQuence IFPower HYS TEES Sarcinii enki matin e usteet ET ame Eg px vetet ES enero TRIGger SEQuence LEVel BBPOWer ort rte erri c rernm rer trennen n ehh i i oen TRIGger SEQuence LE EVeLBBBOWer nti e tre rtp der e eee E pt TRIGger SEQuence EE ek Eegeregie nter re e eod d nieto t Dh ee rcr d xt ka NOE Reda TRIGger SEQuence LP EVel IQPOWSrt 2 oett nt err rr enn rn rne miren ri n TRIGger SEQuence LE EVelRFEBOWer rnnt trente rrr aa TRIGger SEQuence LEVel EXTernal lt port gt Pr TRIGger SEQuence MODE roe otn tree rr en ceri nra exin tra c ra rr EE D Ferne e ERE cra as TRIGger SEQuence SLOBe ttn rer e tree erp de e o Er a MY p TRIGger SEQUENCO F SOURCE E TRIGger SEQuence TIME RINT rv l x7 tun c ii rr etr rene ri rn tid eher UNIT BUR St e A A A OA NO UNI EVM EE UNIT GIMBalance Index A Abbreviations Signal processing IEEE 802 11a g OFDM 54 Aborting WED 146 ee e EE 93 ACLR Configuring cdma2000 CEU Results remote AAA Activating WLAN measurements remote ssss 173 Addi
4. Scaling Factor Numerical value Numerical value x ScalingFac tor Minimum negative int16 value 215 32768 1V 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 lt Min gt lt ArrayOfFloat length 256 gt lt f lt f lt f loat 134 float loat 142 float loat 140 float ArrayOfFloat A 2 2 UO Data File Format iq tar 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 lt float gt 69 lt float gt lt ArrayOfFloat gt lt Max gt lt PowerVsTime gt lt Spectrum gt lt Min gt lt 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 lt float gt 67 lt float gt 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 UO Data Binary File The I Q data is saved in binary format according to the format and data type specified in the XML fil
5. Remote command LAY ADD 1 RIGH SFI see LAYout ADD WINDow on page 248 Or CONFigure BURSt STATistics SFIeld IMMediate on page 182 PvT Full PPDU Displays the minimum average and maximum power vs time diagram for all PPDUs 3 PVT Full PPDU Start 5 0 ps 100 02 ms Stop 165 0 us Fig 3 18 PvT Full PPDU result display for IEEE 802 11a g OFDM ac n p standards mum PENNE XN NN RN NUUS User Manual 1173 9357 02 11 37 R amp S FSW K91 Measurements and Result Displays 2 PVT Full PPDU e 1 Min 2 Avg 3 Max ROMA Rx1 Rx2 Rx3 Rx4 2 1 Rx 1 11 73 ps 116 625 us 625 0 ns 11 73 yus Fig 3 19 PvT Full PPDU result display for IEEE 802 11n MIMO measurements For single carrier measurements IEEE 802 11b g DSSS the PVT results are dis played as percentage values of the reference power The reference can be set to either the maximum or mean power of the PPDU 1 PYT Full PPDU ei Mine 2 Avge 3 Max 94 67 us 941 704545455 us Fig 3 20 PvT Full PPDU result display for IEEE 802 11b y DSSS standards Remote command LAY ADD WIND 2 RIGH PFPP see LAYout ADD 7 on page 248 Or on page 180 gt on page 180 PvT Rising Edge Displays the minimum average and maximum power vs time diagram for the rising edge of all PPDUs User Manual 1173 9357 02 11 38 R amp S FSW K91 Measurements and Result Displays 2 PVT Rising 1 Mine 2 Avge3 Max Fig 3 21 PvT Rising Edge result
6. Parameters lt ChannelType gt EFFective PHYSical RST EFF Example CONF BURS SPEC FLAT CSEL PHYS Configures the Spectrum Flatness and Group Delay result dis plays to calculate the results based on the physical channel Usage Event Configuring the AM AM Result Display The following commands are only relevant for the AM AM result display CONFigure BURSt AM AM POLYnomial lt Degree gt This remote control command specifies the degree of the polynomial regression model used to determine the AM AM result display The resulting coefficients of the regression polynomial can be queried using the CONFigure BURSt AM AM COEFficients command Parameters Degree integer Range 1 to 20 RST 4 Starting a Measurement Example CONF BURS AM AM POLY 3 Manual operation See AM AM on page 23 CONFigure BURSt AM AM COEFficients This remote control returns the coefficients of the polynomial regression model used to determine the AM AM result display Return values lt Coefficients gt comma separated list of numeric values The coefficients are listed in ascending order of degree as dis played in the result display title bar Example CONF BURS AM AM COEF Usage Query only 10 8 Starting a Measurement When a WLAN measurement channel is activated on the R amp S FSW a WLAN IQ mea surement Modulation Accuracy Flatness and Tolerance see chapter 3 1 WLAN IO Measurement Modulation Ac
7. 127 139 Modulation IEEE 802 11 n ac 129 135 Modulation remote sexis ree 301 Ness IEEE 802 11 n 136 220 MEM 129 Nsts IEEE 80211 aC etes 130 231 Payload length Payload length remote AA 233 Phase drift EE 123 219 Physical Channel iii aida 13 15 Pilots cepe te 123 219 PPOWGE SEENEN 13 Power search 121 217 Recognized 13 15 76 Selecting rtt n ence 277 Selecting remole EE 277 Signal field 43 125 127 134 230 Start POSILION scr ap 263 STBC IEEE 802 11 90M ciumaruamnicad 130 136 224 Synchronization MIMO assisas kinna 118 Timing errors 123 220 Total analyzed WER 13 15 Valid atn ert e vied beet eode 76 PPDUs PYT M C X 180 Preamble Channel estimation ssessssssssssss 122 218 Preamplifier SOMO e 106 kn c MH vanes 106 Presetting Channels on crt rrr rne Rx Ennis 90 Default values etre 88 Pretiggef carare 113 Programming examples GE 305 GE 302 WEAN EE 302 Protection aig acid 78 RF input remote EE 186 PSDU ADD lO E 62 PvT Falling edge result display Full PPD accionar Full PPDU result display Rising 8 Falling se Rising edge result display sesessssss PvT Full Burst Ice O 287 Q Quadrature offset E
8. 2 eaten darse reo c Rte te coe iu ento xe eben er er ed 176 SYSTem PRESetCHANnslI EXEQCUte EE 177 INSTrument CREate DUPLicate This command duplicates the currently selected measurement channel i e starts 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 2 Usage Event INSTrument CREate NEW lt ChannelType gt lt ChannelName gt This command adds an additional measurement channel The number of measure ment channels you can configure 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 174 Activating WLAN Measurements 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 174 Example INST CRE SAN Spectrum 2 Adds an addition
9. 272 CAL Culate LIMit ACPower AL Temate chsRESuI seen 272 E ER e FRI A aaa 272 CAL CulateMAb kerEUNCHon POVer sbz RESuIn esa seen 273 GALOulate n MARKersIn X ineo caian cana ERR ER Nn PRI RR EROR RR E as P2 RA naani 275 CAL Cula STAT istics RE Gutts 275 Retrieving Results CALCulate LIMit ACPower ACHannel RESult CALCulate LIMit ACPower ALTernate lt ch gt RESult This command queries the state of the limit check for the adjacent or alternate chan nels in an ACLR measurement 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 sweeps See also INITiate CONTinuous on page 258 Return values lt LowerChan gt text value lt UpperChan gt The command returns two results The first is the result for the lower the second for the upper adjacent or alternate channel PASSED Limit check has passed FAIL Limit check has failed Example INIT IMM WAI CALC LIM ACP ACH RES PASSED PASSED Usage Query only CALCulate LIMit lt k gt FAIL This command queries the result of a limit check For measurements in the R amp S FSW WLAN application the numeric suffix lt k gt speci fies the limit line according to table 10 10 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 resu
10. 286 e EMOPVS Pteatble uu coe erdt E c v e ttt d 286 e EET SOS CUMIN E 287 e Group DOA ieee cin cd rri e e P Ur Hed Ple av encres 287 e Power vs Time Full Burst and Rising Falling Data 287 Signal Feld DE 288 e Spec Flattigss cora 288 AM AM For each sample the x axis value represents the amplitude of the reference signal and the y axis value represents the amplitude of the measured signal Note The measured signal and reference signal are complex signals AM PM For each sample the x axis value represents the amplitude of the reference signal The y axis value represents the angle difference of the measured signal minus the ref erence signal Note The measured signal and reference signal are complex signals AM EVM For each sample the x axis value represents the amplitude of the reference signal The y axis value represents the length of the error vector between the measured signal and the reference signal Note The measured signal and reference signal are complex signals Bitstream Data is returned depending on the selected standard for which the measurement was executed see CONFigure STANdard on page 184 IEEE 802 11a p n and ac standard OFDM physical layers For a given OFDM symbol and a given subcarrier the bitstream result is derived from the corresponding complex constellation point according to Std IEEE802 11 2012 Fig ure 18 10 BPSK QPSK 16 QAM and 64 QAM constellation bit encod
11. Finally the average error vector magnitude is calculated by averaging the packet EVM of all nof_symbols detected packets 1 nof _symbols 2 EVM 2 ae K moa X 014 nof symbols 43 Average error vector magnitude 4 8 Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS This parameter is equivalent to the RMS average of all errors Errorgys of the IEEE 802 11a measurement commandment see 6 4 1 2 Literature on the IEEE 802 11a Standard 1 Speth Classen Meyr Frame synchronization of OFDM systems in frequency selective fading channels VTC 97 pp 1807 1811 2 Schmidl Cox Robust Frequency and Timing Synchronization of OFDM IEEE Trans on Comm Dec 1997 pp 1613 621 3 Minn Zeng Bhargava On Timing Offset Estimation for OFDM IEEE Communication Letters July 2000 pp 242 244 4 Speth Fechtel Fock Meyr Optimum receive antenna Design for Wireless Broad Band Systems Using OFDM Part I IEEE Trans On Comm VOL 47 NO 11 Nov 1999 5 Speth Fechtel Fock Meyr Optimum receive antenna Design for Wireless Broad Band Systems Using OFDM Part II IEEE Trans On Comm VOL 49 NO 4 April 2001 6 IEEE 802 11a Part 11 WLAN Medium Access Control MAC and Physical Layer PHY specifi cations 4 2 Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS This description gives a rough overview of the signal processin
12. Setting Default value CCDF Active on trace 1 Analysis bandwidth 10 MHz Number of samples 62500 Detector Sample For further details about the CCDF measurements refer to Statistical Measurements in the R amp S FSW User Manual To restore adapted measurement parameters the following parameters are saved on exiting and are restored on re entering this measurement e Reference level and reference level offset e Analysis bandwidth e Number of samples 6 Analysis General result analysis settings concerning the trace and markers etc are currently not available for the standard WLAN measurements Only one Clear Write trace and one marker are available for these measurements Analysis of frequency sweep measurements General result analysis settings concerning the trace markers lines etc for RF meas urements are identical to the analysis functions in the Spectrum application except for some special marker functions and spectrograms which are not available in the WLAN application For details see the Common Analysis and Display Functions chapter in the R amp S FSW User Manual The remote commands required to perform these tasks are described in chapter 10 10 Analysis on page 289 D Dan Import Export Functions IO Data Import and Export Baseband signals mostly occur as so called complex baseband signals e a signal representation that consists of two channels the in phase I and the quadrature
13. This command resets the edge detectors and ENAB1e parts of all registers to a defined value All PTRansition parts are set to FFFFh i e all transitions from 0 to 1 are detected All NTRansition parts are set to 0 i e a transition from 1 to O in a CONDition bit is not detected The ENAB1e part of the STATus OPERation and STATus QUEStionable registers are set to 0 i e all events in these registers are not passed on Usage Event STATus QUEue NEXT This command queries the most recent error queue entry and deletes it Positive error numbers indicate device specific errors negative error numbers are error messages defined by SCPI If the error queue is empty the error number 0 No error is returned Usage Query only Reading Out the EVENt Part STATus OPERation EVENt STATus QUEStionable EVENt STATus QUEStionable ACPLimit EVENt lt ChannelName gt STATus QUEStionable LIMit lt n gt 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 Reading Out the CONDition Part STATus OPERation CONDition STATus QUEStionable CONDition STATus QUEStionable ACPLimit
14. This result display is not available for single carrier measurements IEEE 802 11b g DSSS EVM vs Carrier ei Mine2 Avge3 Max Carrier 250 50 1 Carrier Carrier 250 Stream 1 4 Stream 1 Stream 2 Stream 3 Stream 4 3 2 Stream 2 Carrier 122 ES Carrier 122 122 3 3 Stream 3 3 4 Stream 4 Carrier 122 Carrier 122 25 Carrier Fig 3 12 EVM vs carrier result display for IEEE 802 11n MIMO measurements User Manual 1173 9357 02 11 29 R amp S FSW K91 Measurements and Result Displays The numeric trace results for this evaluation method are described in chapter 10 9 4 8 EVM vs Carrier on page 286 Remote command LAY ADD 1 RIGH EVC see LAYout ADD WINDow on page 248 or CONFigure BURSt EVM ECARrier IMMediate on page 179 EVM vs Chip This result display shows the error vector magnitude per chip This result display is only available for single carrier measurements IEEE 802 11b g DSSS Since the R amp S FSW WLAN application provides two different methods to calculate the EVM two traces are displayed 8 EVM vs Chip Vector Error IEEE e 2 EVM Chip 1 27651 6 Chip Chip 276516 e Vector Error IEEE shows the error vector magnitude as defined in the IEEE 802 11b or g DSSS standards see also Error vector magnitude EVM IEEE 802 11b or g DSSS method on page 66 e EVM shows the error vector magnitude calculated with an alternative method that provides higher accuracy
15. DEMod FORMat BANalyze BTYPe AUTO TYPE MGRF SENSe BANDwidth CHANnel AUTO TYPE MB20 See PPDU Format on page 133 Programming Examples R amp S FSW K91 TRIGger SEQuence MODE Source Defines the trigger source Note that this command is maintained for compatibility reasons only Use the TRIGger SEQuence SOURce on page 209 commands for new remote control pro grams This command configures how triggering is to be performed Parameters lt Source gt IMMediate EXTernal VIDeo RFPower IFPower TV AF AM FM PM AMRelative LXI TIME SLEFt SRIGht SMPX SMONo SSTereo SRDS SPILot BBPower MASK PSENsor TDTRigger IQPower EXT2 EXT3 10 13 Programming Examples R amp S FSW K91 This example demonstrates how to configure an EVM measurement in a remote envi ronment e Measurement 1 Measuring Modulation Accuracy for WLAN 802 11n Standard 302 e Measurement 2 Determining the Spectrum Emission Mask 305 10 13 1 Measurement 1 Measuring Modulation Accuracy for WLAN 802 11n Standard This example demonstrates how to configure a WLAN IQ measurement for a signal according to WLAN 802 11n standard in a remote environment 959 2 92 Preparing the application Preset the instrument RST Enter the WLAN option K9ln INSTrument SELect WLAN Switch to single sweep mode and
16. 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 FSW User Manual Remote command MMEMory STORe IQ STATe on page 289 How to Export and Import I Q Data UO data can only be exported in applications that process l Q data such as the l Q Analyzer or optional applications Capturing and exporting UO data 1 Press the PRESET key 2 Press the MODE key and select the IQ Analyzer or any other application that supports UO data Configure the data acquisition Press the RUN SINGLE key to perform a single sweep measurement Select the El Save icon in the toolbar o an Fb o Select the I Q Export softkey How to Export and Import UO Data 7 Inthe file selection dialog box select a storage location and enter a file name 8 Select Save The captured data is stored to a file with the extension ig tar Importing UO data 1 Press the MODE key and select the IQ Analyzer or any other application that supports UO data If necessary switch to single sweep mode by pressing the RUN SINGLE key Select the FJ 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 o a hb o Select Open The stored data is loaded from the file and displayed in the current application Pr
17. LAY ADD 1 RIGH CONS see on page 248 or on page 179 Constellation vs Carrier This result display shows the in phase and quadrature phase results for all payload symbols and all carriers for the analyzed PPDUs of the current capture buffer The Tracking Channel Estimation according to the user settings is applied This result display is not available for single carrier measurements IEEE 802 11b g DSSS The x axis represents the carriers The magnitude of the in phase and quadrature part is shown on the y axis both are displayed as separate traces l trace 1 Q gt trace 2 4Constellation vs Carrier Carrier 250 50 1 Carrier Carrier 250 Streanvi4 Stream 1 Stream2 Stream3 Stream 4 2 2 Stream 2 Carrier 122 Stream 4 Carrier 122 Carrier 122 Fig 3 11 Constellation vs carrier result display for IEEE 802 11n MIMO measurements User Manual 1173 9357 02 11 28 R amp S9FSW K91 Measurements and Result Displays The numeric trace results for this evaluation method are described in on page 285 Remote command LAY ADD 1 RIGH CVC see on page 248 or on page 179 EVM vs Carrier This result display shows all EVM values recorded on a per subcarrier basis over the number of analyzed PPDUs as defined by the Evaluation Range gt Statistics The Tracking Channel Estimation according to the user settings is applied see on page 122 The Minhold Average and Maxhold traces are displayed
18. Parameters lt ChannelType gt lt ChannelName gt Example Channel type of the new channel For a list of available channel types see table 10 3 WLAN WLAN option R amp S FSW K91 String containing the name of the channel INST WLAN Activates a measurement channel for the WLAN application INST WLAN Selects the measurement channel named WLAN for example before executing further commands for that channel Selecting a Measurement 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 90 10 4 Selecting a Measurement The following commands are required to define the measurement type in a remote environment The selected measurement must be started explicitely see chapter 10 8 Starting a Measurement on page 257 For details on available measurements see chapter 3 Measurements and Result Dis plays on page 13 The WLAN IQ measurement captures the UO data from the WLAN signal using a nearly rectangular filter with a relatively large bandwidth This measurement is selected when the WLAN measurement channel is activated The commands to select a different measurement or return to
19. SGL Analyzed PPDUs 1 Magnitude Capture 2 I Clow 6 Spectrum Flatness wo 2 Cirw 3Result Summary Global Bursts Min Mean a 0 0s 4 5 0 ms Carrier 250 50 l4Garrier Carrier 250 2 Constellation 1 Clow 4 EVM vs Symbol s Min Avg Mex 5 EVM vs Carrier Symb 570 Carrier 250 50 1 Carrier 1 Channel bar for firmware and measurement settings 2 Window title bar with diagram specific trace information 3 Diagram area with marker information 4 Diagram footer with diagram specific information depending on result display 5 Instrument status bar with error messages progress bar and date time display User Manual 1173 9357 02 11 10 Understanding the Display Information Channel bar information In the WLAN application the R amp S FSW shows the following settings Table 2 1 Information displayed in the channel bar in the WLAN application Label Description Sample Rate Fs Input sample rate PPDU MCS Index Gl WLAN 802 1 1a ac n The PPDU type MCS Index and Guard Interval used for the analysis of the signal Depending on the demodulation settings these values are either detected automatically from the signal or the user settings are applied PPDU Data Rate WLAN 802 11b The PPDU type and data rate used for the analysis of the signal Depend ing on the demodulation settings these values are either detected auto matically from the signal or the user settings are applied Standard
20. State Activates or deactivates the compensation for UO mismatch gain imbalance quadra ture offset UO skew see chapter 3 1 1 5 I DQ Mismatch on page 19 This setting is not available for standards IEEE 802 11b and g DSSS Parameters State ON OFF ON Compensation for gain imbalance quadrature offset and UO skew impairments is applied OFF Compensation is not applied this setting is required for meas urements strictly according to the IEEE 802 11 2012 IEEE P802 11ac D5 0 WLAN standard RST OFF Manual operation See UO Mismatch Compensation on page 123 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance SENSe TRACking LEVel State Activates or deactivates the compensation for level variations within a single PPDU If activated the measurement results are compensated for level error on a per symbol basis Parameters State ON OFF RST OFF Manual operation See Level Error Gain Tracking on page 123 SENSe TRACking PHASe State Activates or deactivates the compensation for phase drifts If activated the measure ment results are compensated for phase drifts on a per symbol basis Parameters State ON OFF 0 1 RST 1 Manual operation See Phase Tracking on page 123 SENSe TRACking PlLots Mode In case tracking is used the used pilot sequence has an effect on the measurement results Parameters lt Mode gt STANdar
21. The payload length can be defined as a duration in us or a number of bytes only if specific PPDU modulation and format are defined for analysis see PPDU Format to measure PSDU Modulation to use on page 132 Remote command SENSe DEMod FORMat BANalyze DBYTes MIN on page 236 SENSe DEMod FORMat BANalyze DURation MIN on page 237 SENSe DEMod FORMat BANalyze DBYTes MAX on page 235 SENSe DEMod FORMat BANalyze DURation MAX on page 236 PVT Average Length IEEE 802 11b g DSSS Defines the number of samples used to adjust the length of the smoothing filter for PVT measurement For details see PvT Full PPDU on page 37 Remote command CONFigure BURSt PVT AVERage on page 233 PVT Reference Power IEEE 802 11b g DSSS Sets the reference for the rise and fall time in PVT calculation to the maximum or mean PPDU power For details see PvT Full PPDU on page 37 Remote command CONFigure BURSt PVT RPOWer on page 233 Peak Vector Error Meas Range IEEE 802 11b g DSSS Displays the used measurement range for peak vector error measurement for refer ence only All Symbols Peak Vector Error results are calculated over the complete PPDU PSDU only Peak Vector Error results are calculated over the PSDU only Remote command CONFigure WLAN PVERror MRANge on page 234 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 10 Result Configuration For some resu
22. e improving POrfOrmiahog orien ias eoe Ee Er e ED HE E EE sine 164 e Improving Channel Estimation and EVM ACcuracN 164 Improving Performance Performing a coarse burst search For signals with low duty cycle rates enable the Power Interval Search for synchro nization see Power Interval Search on page 121 In this case the R amp S FSW WLAN application initially performs a coarse burst search on the input signal in which increa ses in the power vs time trace are detected Further time consuming processing is then only performed where bursts are assumed This improves the measurement speed However for signals in which the PPDU power levels differ significantly this option should be disabled as otherwise some PPDUs may not be detected Improving Channel Estimation and EVM Accuracy The channels in the WLAN signal are estimated based on the expected input signal description and the information provided by the PPDUs themselves The more accu rate the channel estimation the more accurate the EVM based on these channels can be calculated Increasing the basis for channel estimation The more information that can be used to estimate the channels the more accurate the results For measurements that need not be performed strictly according to the WLAN 802 11 standard set the Channel Estimation Range to Payload see Chan nel Estimation Range on page 122 The channel estimation is performed in the preamble and the payloa
23. lt Windowlndex_n gt User Manual 1173 9357 02 11 250 Configuring the Result Display Return values lt WindowName gt string Name of the window In the default state the name of the window is its index Windowlndex numeric value Index of the window Example LAY CAT Result Unies tt Two windows are displayed named 2 at the top or left and 1 at the bottom or right Usage Query only LAYout IDENtify WINDow lt WindowName gt This command queries the index of a particular display window 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 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 while keeping its position index and window name To add a new window use the LAYout ADD WINDow command R amp S FSW K91 Remote Commands for WLAN Measurements WEEN Parameters lt WindowName gt String containing the name of
24. the results are grouped by PPDU PPDU 1 PLCP Preamble 120 PLCP Header 11111111 11111111 11111111 11111111 11111111 11111111 01010000 00000100 10000000 10011100 11111111 11111111 11111111 11111111 11111111 00000101 00100000 11001000 01000010 10101011 11111111 11111111 11111111 11111111 11111111 11001111 00000000 01000110 00110000 00001101 00010100 Fig 3 9 Bitstream result display for IEEE 802 11b g DSSS standards The numeric trace results for this evaluation method are described in On page 283 Remote command LAY ADD 1 RIGH BITS see or User Manual 1173 9357 02 11 on page 248 on page 182 26 R amp S FSW K91 Measurements and Result Displays Constellation This result display shows the in phase and quadrature phase results for all payload symbols and all carriers for the analyzed PPDUs of the current capture buffer The Tracking Channel Estimation according to the user settings is applied The inphase results Il are displayed on the x axis the quadrature phase Q results on the y axis Stream 1 4 Stream 1 Stream2 Stream3 Stream 4 2 2 Stream 2 2 3 Stream 3 2 4 Stream 4 Fig 3 10 Constellation result display for IEEE 802 11n MIMO measurements User Manual 1173 9357 02 11 27 R amp S FSW K91 Measurements and Result Displays The numeric trace results for this evaluation method are described in on page 285 Remote command
25. 1 D1 IEEE 802 11N All PPDUs are analyzed assuming the specified STBC field content Demod all as STBC field 2 D2 IEEE 802 11N All PPDUs are analyzed assuming the specified STBC field content Meas only if STBC 1 Nsts 2Nss M1 IEEE 802 11AC Only PPDUs with the specified STBC field content are analyzed Demod all as STBC 1 Nsts 2Nss D1 IEEE 802 11AC All PPDUs are analyzed assuming the specified STBC field content Remote command CONFigure WLAN STBC AUTO TYPE on page 224 Extension Spatial Streams sounding Defines the PPDUs taking part in the analysis according to the Ness field content Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display NESS column see Signal Field on page 43 Auto same All PPDUs using a Ness value identical to the first recognized PPDU type as first are analyzed PPDU A1st Auto individu All PPDUs are analyzed ally for each PPDU Al WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Meas only if Only PPDUs with the specified Ness value are analyzed Ness lt x gt M ax Demod allas All PPDUs are analyzed assuming the specified Ness value Ness lt x gt Remote command CONFigure WLAN EXTension AUTO TYPE on page 220 Table info overview Depending on the selected channel bandwidth MCS index or NSS STBC the rele vant information fr
26. Activating remote cecceeeceeseereeeeeeeeeerenteeneeteees 292 Area Multiple mode remote sssssss 292 Area remote sses Multiple mode remote ue Single mode remote 1
27. DSSS only Return values lt Range gt ALL PSDU ALL Peak Vector Error results are calculated over the complete PPDU PSDU Peak Vector Error results are calculated over the PSDU only Usage Query only Manual operation See Peak Vector Error Meas Range IEEE 802 11b g DSSS on page 141 SENSe BURSt COUNt lt Value gt If the statistic count is enabled see SENSe BURSt COUNt STATe on page 235 the specified number of PPDUs is taken into consideration for the statistical evaluation maximally the number of PPDUs detected in the current capture buffer If disabled all detected PPDUs in the current capture buffer are considered Parameters lt Value gt RST 1 Example SENS BURS COUN STAT ON SENS BURS COUN 10 Manual operation See PPDU Statistic Count No of PPDUs to Analyze on page 140 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance SENSe BURSt COUNt STATe lt State gt If the statistic count is enabled the specified number of PPDUs is taken into considera tion for the statistical evaluation maximally the number of PPDUs detected in the cur rent capture buffer If disabled all detected PPDUs in the current capture buffer are considered Parameters lt State gt ON OFF RST OFF Example SENS BURS COUN STAT ON SENS BURS COUN 10 Manual operation See PPDU Statistic Count No of PPDUs to Analyze on page 140 SENSe DEMod FORMat
28. 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 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 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 SCPI Parameters Many commands feature one or more parameters If a command supports more than one parameter these are separated by a comma Example LAYout ADD WINDow Spectrum LEFT MTABle 10
29. Frequency tab to define the input signal s center frequency The reference level is adapted automatically 6 Select the Signal Capture button to define how much and which data to capture from the input signal 7 Select the MIMO Capture tab to define how the data from the MIMO antennas is to be captured a Forthe DUT MIMO Config select the number of TX antennas data will be transmitted from b Under MIMO antenna Signal Capture Setup select Sequential Manual R amp S9FSW K91 How to Perform Measurements in the WLAN Application 8 To define a particular starting point for the FFT or to improve the measurement speed for signals with a low duty cycle select the Synchronization OFDM Demod button and set the required parameters 9 Select the Tracking Channel Estimation button to define how the data channels are to be estimated and which distortions will be compensated for e g crosstalk between the MIMO antennas at the DUT 10 Select the Demod button and then the Demod tab to provide information on the modulated signal and how the PPDUS detected in the capture buffer are to be demodulated 11 In the Demodulation dialog box select the MIMO tab to define which spatial mapping mode is used that is how the space time streams are mapped to the antennas a If necessary include a time shift for the individual antennas b Ifthe signal power is amplified according to the maxtrix entries so that the total tr
30. OFFSel 3 c reta it divin acct 198 SENSe FREQuency CENTer Frequency This command defines the center frequency Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Frequency gt 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 Frequency on page 91 See Center Frequency on page 98 See Center frequency on page 101 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 196 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
31. Parameters lt State gt ON Differential OFF Simple ended RST ON Example INP IQ BAL OFF Manual operation See Input configuration on page 98 INPut IQ FULLscale AUTO State This command defines whether the full scale level i e the maximum input power on the Baseband Input connector is defined automatically according to the reference level or manually Parameters State ON Automatic definition OFF Manual definition according to INPut 10 FULLscalel LEVel on page 192 RST ON Example INP IQ FULL AUTO OFF INPut IQ FULLscale LEVel lt PeakVoltage gt This command defines the peak voltage at the Baseband Input connector if the full scale level is set to manual mode see 1NPut 10 FULLscale AUTO on page 192 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt PeakVoltage gt Example 0 25 V 0 5 V 1V 2V Peak voltage level at the connector For probes the possible full scale values are adapted according to the probe s attenuation and maximum allowed power RST 1V INP IO FULL 0 5V INPut IQ TYPE lt DataType gt This command defines the format of the input signal Parameters lt DataType gt Example Manual operation IQ I Q IO The input signal is filtered and resampled to the sample rate of the application Two input channels are required for each input signal one for the in phase component and one for the quadrature c
32. The quadrature error is a measure for the crosstalk of the Q branch into the I branch Quadrature Error ARG Go jx Aga Quadrature error crosstalk 4 12 The normalized UO offset is defined as the magnitude of the UO offset normalized by the magnitude of the reference signal IQ Offset 1 Q offset 4 13 At this point of the signal processing all unknown signal parameters such as timing off set frequency offset phase offset UO offset and gain imbalance have been evaluated and the measurement signal can be corrected accordingly Error vector magnitude EVM R amp S FSW method Using the corrected measurement signal r v and the estimated reference signal v the modulation quality parameters can be calculated The mean error vector magnitude EVM is the quotient of the root mean square values of the error signal power and the reference signal power A me 3 te c EVM JE es N A 2 LO v 0 Mean error vector magnitude EVM 4 14 Whereas the symbol error vector magnitude is the momentary error signal magnitude normalized by the root mean square value of the reference signal power Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS EVM v ey 0 12 sf Error vector magnitude EVM IEEE 802 11b or g DSSS method Symbol error vector magnitude 4 15 In 2 a different algorithm is proposed to calculate the error vector magnitude In a first step the IQ o
33. before it reaches the trigger level again on the rising edge On the falling edge however two trigger events occur as the signal exceeds the hysteresis before it falls to the trigger level the second time Trigger level Fig 4 7 Effects of the trigger hysteresis See Hysteresis on page 114 4 9 3 Trigger Drop Out Time If a modulated signal is instable and produces occassional drop outs during a burst you can define a minimum duration that the input signal must stay below the trigger level before triggering again This is called the drop out time Defining a dropout time helps you stabilize triggering when the analyzer is triggering on undesired events Triggered measurements d uw Y Drop Out Fig 4 8 Effect of the trigger drop out time See Drop Out Time on page 113 D Drop out times for falling edge triggers If a trigger is set to a falling edge Slope Falling see Slope on page 114 the measurement is to start when the power level falls below a certain level This is useful for example to trigger at the end of a burst similar to triggering on the rising edge for the beginning of a burst If a drop out time is defined the power level must remain below the trigger level at least for the duration of the drop out time as defined above However if a drop out time is defined that is longer than the pulse width this condition cannot be met before the final pulse so a trigger event will not o
34. exists the default name extended by a sequential number is used for the new channel Activating WLAN Measurements Application lt ChannelType gt Parameter Default Channel Name 1xEV DO BTS R amp S FSW BDO 1xEV DO BTS K84 1xEV DO MS R amp S FSW MDO 1xEV DO MS K85 WLAN R amp S FSW K91 WLAN WLAN LTE R amp S FSW K10x LTE LTE Realtime Spectrum RTIM Realtime Spectrum R amp S FSW K160R 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 lt ChannelName2 gt Example String containing the name of the channel you want to rename 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 INST REN Renames the channel with the name Spectrum2 to Spectrum3 Spectrum2 Spectrum3 INSTrument SELect lt ChannelType gt lt ChannelName gt This command activates a new measurement channel with the defined channel type or selects an existing measurement channel with the specified name See also INSTrument CREate NEW on page 173 For a list of available channel types see INSTrument LIST on page 174
35. 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 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 Setting parameters lt SumBit gt Range 0 to 65535 Usage SCPI confirmed STATus QUEStionable DIQ 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 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 Setting parameters lt BitDefinition gt Range 0 to 65535 STATus QUEStionable DIQ PTRansition lt BitDefinition gt lt ChannelName gt This command controls 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 als
36. multiple input single output MISO However space division multiplexing requires two or more analyzers to calculate the precoding matrix and demodulate the signals The R amp S FSW WLAN application provides the following methods to capture data from the MIMO antennas e Simultaneous MIMO operation The data streams are measured simultaneously by multiple analyzers One of the analyzers is defined as a master which receives the l Q data from the other ana lyzers the slaves The IP addresses of each slave analyzer must be provided to User Manual 1173 9357 02 11 71 R amp S FSW K91 Measurement Basics IEN the master The only function of the slaves is to record the data that is then accu mulated centrally by the master Note that only the MIMO master analyzer requires the R amp S FSW K91n or ac option The slave analyzers do not require a R amp S FSW WLAN application The number of Tx antennas on the DUT defines the number of analyzers required for this measurement setup The master calculates the measurement results based on the l Q data captured by all analyzers master and slaves and displays them in the selected result displays e Sequential using open switch platform The data streams are measured sequentially by a single analyzer connected to an additional switch platform that switches between antenna signals No manual inter action is necessary during the measurement The R amp S FSW WLAN application captures the UO
37. which is available at the bottom of all softkey menus Overview 1 eset WLAN Modulation Act y Spectral Flatness Center Fre Ret vi Attenuation Capture Length Trigger Mode Sample Rate MIMO No Rx Power Interval Search MIMO Capture FET Start Offset fn Synchronization Signal Capture OFDM Demod Evaluation Range Display Config PPDU Stat Count Magnitude Capture eset 1 Magnitude Capture gt The Overview not only shows the main measurement settings it also provides quick access to the main settings dialog boxes The indicated signal flow shows which parameters affect which processing stage in the measurement 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 The available settings and functions in the Overview vary depending on the currently selected measurement For frequency sweep measurements see chapter 5 4 Fre quency Sweep Measurements on page 147 For the WLAN IQ measurement the Overview provides quick access to the following configuration dialog boxes listed in the recommended order of processing 1 Select Measurement See Selecting the measurement type on page 85 2 Signal Description See chapter 5 3 3 Signal Description on page 91 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 3 Input Frontend See and
38. 2 6 1 Introduction Parameters may have different forms of values e N mene VAG OSs EEN tern rto n Sen AANEREN aad n hana e si n ee e a n uere e E nera UTR 171 e IBOOlGBM sete tice ee ce eani en b e a n eer e at PO aca e UE 172 e Character RE EE 172 e en EEN E 172 e IBIOOK DAA EE 172 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 1E9 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 e MIN MAX Defines the minimum or maximum numeric value that is supported e DEF Defines the default value 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 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 decim
39. 220 Quadrature phase angle Q 18 19 Quadrature O fSGL is cci emere ente t tatnen fein 13 Status bits 293 A O 13 Estimates Signal processing IEEE 802 11a g OFDM 56 Estimating Channels IEEE 802 11a g OFDM 60 Evaluation methods Frequency sweep measurement n 51 Remote A Poner ere s nime 279 MIIEAN WEE 21 Evaluation range EE E 232 Result displays Settings a151 EVM NIESEN siii eaa 13 Calculating IEEE 802 11a g OFDM 60 Calculating WLAN ucc t ctc rene n ce 20 Data caiie S miii aia 13 Data carriers limit check result remote 269 270 VQ diagram cernere terere 21 IEEE 802 11b g DSSS nem 21 Limit check result remote esses 269 Limits remote rdiet ees 239 240 OPTIMIZING WEE 122 218 Pilot iCat ets 13 Pilot carriers limit check result remote 270 PPDU ileeb o sie tetro at ie re ers 20 Units nar 268 vs carrier result display 5 mieten 29 vs carrier trace dala snc 286 vs chip result display uoce iere ree cem 30 vs symbol result display eeseeesess 30 Exporting VQ data 92 152 153 312 316 l GQdata remote ioi c rennin 288 GE 153 Extension Spatial Streams PPDUS eent ees rabos 136 220 External trigger Level remote o
40. 224 DIAGnostic SERVice NSOurce DISPIAy FORMat insta DISPlay WINDow lt n gt SELect DISPlayEWINDOWSR gt TSIZE oo A ta DISPlayEWINDow lt n gt TABLe TEM cusco n 255 DISPlay WINDowsn TRAGe Y SCALe RL EVel 2 1 irte reor tnt rrr nens 199 DISPlay WINDow lt n gt TRACe Y SCALe RLEVel OF FSet eee cece cece renee seiniin 199 DISPlay WINDow lt n gt ZOOM AREA DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt AREA cere eeee eens eira deiina 292 DISPlay WINDow n ZOOM MULTiple zoom STATe sess rennen rennen nennen 292 DISPlayEWINDowsn ZOOMY S RE 292 FETCHN BURSEALL itr te m t nen ee RD De d e EX RR X n e d Ee ra PEE AAA 265 FETCMBURSECOUNCAL i 263 FETGR BURSEGONUN unir i eret etienne RD EA FO Y YE FE YR EXPE ER REX E FE REN dada 262 FETCh BURSECRESEMPAXImUulTI 1 itr t e hr tpe aaa 265 FETEMBURSECRESEMIN MU lara veer ta exegit sched kn Pee BL A eer rate e aenea B eebe 265 FETCRh BURSECRESI AVERage t e enti rr eri epe nere reb n e XR tpa e EC eges 265 FETCRh BURSEEVM ALL AVERageY crt retten nee te re ere PEE XC n Re E REY XE dE ERE 265 FETCh BURSt EVM ALL AVERage FETCh BURSt EVM ALL MAXimum FETCH BURSTEVM ALLEMAXIMUN ranita rota ea 267 FETCH BURSEEVM ALLE MINIMUM Lct iia ates 265 FETEN BURSEEVM ALCIEMINIMU RE 267 EETCh BURSCEEVM IDATA AMERGBQgO epe IER GE 266 FETCH BURSEEVM DATAMAXIMUN scoth roroesan Sua at oi 266 FETCh BURSt
41. 271 CALCulate LIMitBURSEIOOFTSetEAVERAGe E 241 CAL Culatel IMC BURGrClOOFtsef AVERaoeltRE Gut 271 CALCulate LIMi BURStSY MBolerror MAXIMUM EE CALCulate LIMit BURSt SYMBolerror MAXimum RESult CALOCulate LIMit BURSt SYMBolerror AVERage esses enne nennen nennen CAL CGulate IMC BURG SvMolerrort AVChaoel RE GO 271 CAL Culate Ben OLSranCe ciar tienen dees 185 CAL Culate EIMItek gt FAME ooo iia 272 CAL Culate MARKer FUNCtion POWer lt sb gt RESUlP AA 273 CALGulate STATISHES TEE 275 CAL Culatesns BURSt IMMediate 3 rented ie eee li 258 ed e EE 275 CAL Culate lt n gt iMARKGrsm gt Y EEN 290 CALGulatesn MARKersm STATE uico rette neither ra peste Eb euch deba ke Peel HELM eX re Pe eH RR Re ea ua 290 CALCulate lt n gt UNIT POWer CALibraiom AlQ DCOFfS t TEE 193 CALibration AlQ DEOFISCEO ME 194 GONFig re BURSEAM AM COEFfICIGDES 2 c dass aree reta A NETE AENEAS 257 CONFig re BURSEAM AM POEYnotmlal ciet nte ettet Aa S 256 CONFig re BURSEAM AMEIMMediate 1 rectos oat ret etr tbt eet hp tr eiie dei 178 GONFigure BURSEAM EVMEIMMediate seaside eon c et corra rct eere rece ect ducet 178 CONFigure BURSt AM PM MMediate CONFioure BURGCCONSrCCAbrtert IMMedatel cn nre nnn nennen 179 CONFioure BURGCCONSrCCSvMboltlMMedatel AAA 179 CONFigure BURSEEVM EGARrIer IMMediat icti ara a 179 CONFig re BURSCEVM ECHip IMMediate irt oe aisi pa addebat
42. 802 11b 4 IEEE 802 119 6 7 IEEE 802 11n 8 IEEE 802 11ac 9 IEEE 802 11p RST 0 Manual operation See Standard on page 91 CALCulate LIMit TOLerance Limit This command defines or queries the tolerance limit to be used for the measurement The required tolerance limit depends on the used standard Parameters lt Limit gt PRIOR11 2012 STD11 2012 P11ACD5 1 PRIOR11 2012 Tolerance limits are based on the IEEE 802 11 specification prior to 2012 Default for OFDM standards except 802 11ac STD11 2012 Tolerance limits are based on the IEEE 802 11 specification from 2012 Required for DSSS standards Also possible for OFDM stand ards except 802 11ac P11ACD5 1 Tolerance limits are based on the IEEE 802 11ac specification Required by IEEE 802 11ac standard RST STD11 2012 Manual operation See Tolerance Limit on page 91 Configuring the Data Input and Output pigs m E 186 Contiguiing Digital Q Input and QUtPUt ET 188 Configuring Input via the Analog Baseband Interface R amp S FSW B71 191 Configuring the Outpuls teet tr es sede tee a gastos a a aai 195 10 5 2 1 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance RF Input INPutATTenuation PROTection RESet 23 c cs ccsecectessaacecassccedencanssnancoezatccudnccesacceaeenanas 186 NPU COUPIO Ss sca 186 INPut FIbTerHPASSBESTATe EE 186 INPULPILT er VIGE
43. BANalyze SYMBols EQUal command is set to false this command specifies the minimum number of payload symbols required for a PPDU to take part in measurement analysis The number of payload symbols is defined as the uncoded bits including service and tail bits Parameters lt NumDataSymbols gt RST 1 Example SENS DEM FORM BAN SYMB EQU ON SENS DEMO FORM BANA SYMB MIN Manual operation See Min Max No of Data Symbols IEEE 802 11a g OFDM ac n p on page 141 10 5 9 Limits The following commands are required to define the limits against which the individual parameter results are checked Principally the limits are defined in the WLAN 802 11 standards However you can change the limits for your own test cases and reset the limits to the standard values later Note that changing limits is currently only possible via remote control not manually via the user interface The commands required to retrieve the limit check results are described in chap ter 10 9 1 3 Limit Check Results on page 269 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Useful commands for defining limits described elsewhere e UNIT EVM on page 268 e UNIT GIMBalance on page 268 Remote commands exclusive to defining limits GAL Gulate EIMIEBURSEARLDL 2 tetur eant iaa 239 CALOCulate LIMit BURSt EVM ALL AVERage esee nnne 239 GALCulate LIMIEBB
44. BTYPe AUTO TYPE on page 228 SENSe DEMod FORMat BANalyze on page 227 5 3 8 2 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance PSDU Modulation If analysis is restricted to PSDU with a particular modulation type this setting defines which type For details on supported modulation depending on the standard see table 4 1 Remote command SENSe DEMod FORMat BANalyze on page 227 Demodulation IEEE 802 11ac The following settings are available for demodulation of IEEE 802 11ac signals Demodulation alyze PPDU Analysis Mode Auto same type as first PPDU PPDU Format to measure Auto same type as first PPDU Channel Bandwidth to measure Auto same type as first PPDU H up to CBW160 MHz MCS Index to use Auto same type as first PPDU MCS Index Nsts to use Auto same type as first PPDU Nsts STBC Field Auto same type as first PPDU Data Rate Mb s 800ns GI 400ns GI QPSK 58 5 65 Modulation Guard Interval Length Fig 5 3 Demodulation settings for IEEE 802 11ac standard PPDU Analysis MOodg ioter eerte ie eate etti ere ete PP DW Format to dqneasUle E Channel Bandwidth to measure CDW rana MCS Index to ub urit t rt ed verc tti deed n egg tds Vues e M S PPDU Analysis Mode Defines whether all or only specific PPDUs are to be analyzed WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Auto same type as first PPDU T
45. Carr C 7 Carrier 25 Carr rrier Carrier 25 Carr P Carrier 25 Carr 2 5 Stream 2 Rx 1 2 6 Stream 2 Rx 2 2 7 Stream 2 Rx 3 2 8 Stream 2 Rx 4 Carrier 25 Carr Carrie Carrier 25 Carr Carrier Carrier 25 Carr C ner 25 Carr 2 9 Stream 3 Rx 1 2 10 Stream 3 Rx 2 2 11 Stream 3 Rx 3 2 12 Stream 3 Rx 4 Carrier 25 Carr arrie Carrier 25 Carr e 25 Carr Carrier 25 Carr 2 13 Stream 4 Rx 1 2 14 Stream 4 Rx 2 stream 4 Rx 3 2 16 Stream 4 Rx 4 Carrier 25 Car Carrie Carrier 25 Carr Fig 3 27 Spectrum flatness result display for IEEE 802 11n MIMO measurements The numeric trace results for this evaluation method are described in chap ter 10 9 4 14 Spectrum Flatness on page 288 Remote command LAY ADD 1 RIGH SFL see LAYout ADD WINDow on page 248 or CONF BURS SPEC FLAT SEL FLAT see CONFigure BURSt SPECtrum FLATness SELect on page 181 and CONFigure BURSt SPECtrum FLATness IMMediate on page 182 El 3 2 Frequency Sweep Measurements As described above the WLAN IQ measurement captures the l Q data from the WLAN signal using a nearly rectangular filter with a relatively large bandwidth However some parameters specified in the WLAN 802 11 standard require a better signal to noise level or a smaller bandwidth filter than the UO measurement provides and must be determined in separate measurements Parameters that are common to several digital standards and are often required in sig nal and sp
46. DUT If possible the transmitterR amp S FSW and the DUT should be synchronized using an external reference See R amp S FSW User Manual gt Instrument setup gt External reference Symbol clock error ppm Clock error between the signal and the sample clock of the R amp S FSW in parts per million ppm i e the symbol timing error the corresponding limits speci fied in the standard are also indicated If possible the transmitterR amp S FSW and the DUT should be synchronized using an external reference See R amp S FSW User Manual gt Instrument setup gt External reference 1 Q offset dB Transmitter center frequency leakage relative to the total Tx channel power see chapter 3 1 1 1 I Q Offset on page 16 Gain imbalance dB Amplification of the quadrature phase component of the signal relative to the amplification of the in phase component see chapter 3 1 1 2 Gain Imbal ance on page 17 the limits can be changed via remote control not manually see chapter 10 5 9 Limits on page 238 in this case the currently defined limits are displayed here WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Parameter Description Quadrature offset Deviation of the quadrature phase angle from the ideal 90 see chap ter 3 1 1 3 Quadrature Offset on page 18 PPDU power dBm Mean PPDU power Crest factor dB The ratio of the peak power to the m
47. DiSblavlfWiNDow cnzt lzt eee eeseeesaeae aaa nora rra 247 DISPlay FORMat lt Format gt This command determines which tab is displayed Parameters lt Format gt SPLit Displays the MultiView tab with an overview of all active chan nels SINGle Displays the measurement channel that was previously focused RST SING Example 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 252 Configuring the Result Display Parameters lt Size gt 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 10 7 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 lt n gt always refers to the window in the currently selected meas
48. EVM DATA MINimum 266 FETCH BURSTEVM PILOtAVERAagO cional A Dd la ve E 266 FETCH BURSEEVM PlLOtMAXIMUN Pcia iaa 266 FETCR BURSEEVM PIEOEMIBNITUED oops ia a ia 266 FETCH BURSEFERROFAVERAGQG E 266 FETCH BURSEFERROSMAXIMUN RE 266 FETCHN BURSEFERROEMINIMUM iras ad 266 EETCh BURSEGIMBalance AVERa Qe2 i I eerie tie oc dpt eer tit e un Pe ghe 266 FETCh BURSEGIMBalance MAXIUltTI aio t ida 266 FETCh BURSEGIMBalance MINIMUM Psi aieo a er rea oda erret cM Porch co freu e ze ebore rea 266 EETGh BURSEIQOFfSeUAVERaAQO c rtt eec eie o te Ep er bote ved enema coe apod 267 FETCh BURSEIQOFTSet MAXIRYUITI cut coo deett ame cipe doses espace lee deaee a dacde oboe us 267 FETCh BURSEIQOFISet MINIMUM i 22 5 ccrta rrt cec o 267 EETGR BURSEBENGIS iii rre A pg tae se pea tu tee Die e o rupe os tel maa 263 FETCh BURSEPAYEoad MAXIERDUEMD uice ia cb rette races ia arias 267 FETCR BURSEPAYEOadMINIEGUITI 02e ert ctetu to cert eye tte 267 E Reie RE E dE IR AS ER 267 FETCh BURSEPEAKMAXImUIT inicia 267 EETGI BURSCPEAK AVERagSe tette e re peste AIRES 267 FEICh BURSCPREamble MAXIUIT icai A aia EO 267 FETCh BURSEPREambIe MINIMUM cioe oce cott rr ecco eer been it bct ab ea UMSO e ER e ed 267 FETJGI BURSCPREambIe AVERage 2 E 267 FETCH BURSEQUADOTISCEAVERAGEC itecto deor nd e ot beni a a ER Rn Ke LE Ule dui re eee ed 268 FETCRh BURSEQUADeffset MAXIImUtm is iii en nnn ri Xa err hne 268 FETCh BURSt
49. EVM all carriers 0 1 max EVM all carriers 0 5 average EVM data carriers 0 1 max EVM data carriers 0 5 average EVM pilots 0 1 max EVM pilots 0 5 CALC LIM BURS ALL 5 10 5 10 5 10 0 1 0 5 0 1 0 5 0 1 0 lt 5 Performing the Measurements Run 10 blocking single measurements INITiate IMMediate WAI Retrieving Results Query the I Q data from magnitude capture buffer for first ms 200 000 samples per second gt 200 samples TRACel IQ DATA MEMory 0 200 Note result will be too long to display in IECWIN but is stored in log file Query the 1 0 data from magnitude capture buffer for second ms TRACe1 10 DATA MEMory 201 400 Note result will be too long to display in IECWIN but is stored in log file Programming Examples R amp S FSW K91 Select window 4 EVM vs carrier DISP WIND4 SEL Query the current EVM vs carrier trace TRAC DATA TRACE Note result will be too long to display in IECWIN but is stored in log file Query the result of the average EVM for all carriers FETC BURS EVM ALL AVER Query the result of the EVM limit check for all carriers CALC HIN BURG ALL RES Return to standard defined limits CALC LIM BURS ALL Query the result of the EVM limit check for all carriers again CALC LIM BURS ALL RES seeks Exporting Captured I Q Data Store the captured I Q data to a file
50. Header and parame ters are separated by a white space ASCII code 0 to 9 11 to 32 decimal e g blank 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 FSW Remote command examples Note that some remote command examples mentioned in this general introduction may not be supported by this particular application Conventions used in Descriptions Note the following conventions used in the remote command descriptions e Command usage 10 2 2 10 2 3 Introduction 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 e 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 SCPI standard are indicated as SCPI con firmed All commands used by the R amp S FSW follow the SCPI syntax rules e Async
51. I Imag part of the complex element of the STS Stream lt STS Q gt Real part of the complex element of the STS Stream Example CONF WLAN SMAP TX4 STR1 1 0 1 0 Manual operation See User Defined Spatial Mapping on page 139 CONFigure WLAN SMAPping TX ch TIMeshift lt TimeShift gt This remote control command specifies the timeshift for a specific antenna Parameters lt TimeShift gt Time shift in s for specification of user defined CSD cyclic delay diversity for the Spatial Mapping Range 32 ns to 32 ns Manual operation See User Defined Spatial Mapping on page 139 CONFigure WLAN STBC AUTO TYPE lt PPDUType gt This remote control command specifies which PPDUs are analyzed according to STBC streams for IEEE 802 11n ac standards only Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt PPDUType gt FBURst ALL MO M1 M2 DO D1 D2 FBURst The STBC of the first PPDU is detected and subsequent PPDUs are analyzed only if they have the same STBC corresponds to Auto same type as first PPDU ALL All recognized PPDUs are analyzed according to their individual STBC corresponds to Auto individually for each PPDU MO M1 M2 Measure only if STBC field 0 1 2 For details see STBC Field on page 130 DO D1 D2 Demod all as STBC field 0 1 2 For details see STBC Field on page 130 Example CONF WLAN STBC AUTO TYPE MO Manual operatio
52. IEEE 802 113 d OFDM recurs eterne 61 Log likelihood function IEEE 802 11a g OFDM Logical filter aiii Long symbol LS IEEE 802 118 9 OFDM stis 56 Lower Level Hysteresis Ge tire er eren 146 Magnitude Capture Ixesultdisplay icc eror reine roii ecos 34 Trace data m 279 Marker Functions A T E A 87 Marker table Evaluation method retreat 52 Markers Configuration remote ssssse Querying position remote Table evaluation method Maximizing Windows remote se OA eror etre Rire teres BICI Displayed Displayed information REMOtE EH Measurement channel Creating remote sse Deleting remote AAA Duplicating remote s Querying remote Renaming remote eese Replacing remote sse Selecting Femote seccatid der saldo Measurement time Auto settings ROMO EE Measurements Frequency SWEEP EE 47 Ei e 48 RF types mu 48 Sel amp cting RE 85 90 Selecting remote oooonocccnnncccnnoccccconcccnnoncccnnancconannos 177 Setup displayed 11 Starting remote Zool TIPOS mataro ET 13 Messages Signal Field escocia cite 165 MIMOS scort dd 67 Antenna assignment TA Calculating results 2120 Capture buffers 2120 Capture method an 146 Capture settings 2 115 Demodu
53. IEEE 802 11N All PPDUS are analyzed assuming the specified STBC field content Meas only if STBC 1 Nsts 2Nss M1 IEEE 802 11AC Only PPDUs with the specified STBC field content are analyzed Demod all as STBC 1 Nsts 2Nss D1 IEEE 802 11AC All PPDUs are analyzed assuming the specified STBC field content Remote command CONFigure WLAN STBC AUTO TYPE on page 224 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Table info overview Depending on the selected channel bandwidth MCS index or NSS STBC the rele vant information from the modulation and coding scheme MCS as defined in the WLAN 802 11 standard is displayed here This information is for reference only for example so you can determine the required data rate Guard Interval Length Defines the PPDUs taking part in the analysis depending on the guard interval length Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display GI column see Signal Field on page 43 Auto same type as first PPDU A1st All PPDUS using the guard interval length identical to the first recog nized PPDU are analyzed Auto individually for each PPDU Al All PPDUs are analyzed Meas only Short MS Only PPDUs with short guard interval length are analyzed Meas only Long ML Only PPDUs with long guard interval length are analyzed Demod all as short DS All P
54. Level on page 145 10 5 11 Sweep Settings GENSeTSWEepCOUN ettet tet tet tete testet testes testo ss 244 SENSe SWEep COUNt lt SweepCount gt This command defines the number of sweeps that the application uses to average traces In case of continuous sweeps the application calculates the moving average over the average count In case of single sweeps the application stops the measurement and calculates the average after the average count has been reached Example SWE COUN 64 Sets the number of sweeps to 64 INIT CONT OFF Switches to single sweep mode INIT WAI Starts a sweep and waits for its end Usage SCPI confirmed Configuring Frequency Sweep Measurements on WLAN Signals 10 6 Configuring Frequency Sweep Measurements on WLAN Signals The R amp S FSW WLAN application uses the functionality of the R amp S FSW base system Spectrum application see the R amp S FSW User Manual to perform the WLAN fre quency sweep measurements The R amp S FSW WLAN application automatically sets the parameters to predefined settings as described in chapter 5 4 Frequency Sweep Measurements on page 147 The WLAN RF measurements must be activated for a measurement channel in the WLAN application see chapter 10 3 Activating WLAN Measurements on page 173 For details on configuring these RF measurements in a remote environment see the Remote Commands chapter of the R amp S FSW User Manual Remote commands exclusive
55. MMEM STOR IQ STAT 1 C R_S Instr user data iq tar 10 13 2 Measurement 2 Determining the Spectrum Emission Mask RST Reset the instrument INST CRE NEW WLAN SEMMeasurement Activate a WLAN measurement channel named SEMMeasurement 7 Configuring the measurement DISP TRAC Y SCAL RLEV 0 Set the reference level to 0 dBm FREQ CENT 2 1175 GHz Set the center frequency to 2 1175 GHz CONF BURS SPEC MASK Select the spectrum emission mask measurement Performing the Measurement INIT CONT OFF Stops continuous sweep SWE COUN 100 Sets the number of sweeps to be performed to 100 INIT WAI Start a new measurement with 100 sweeps and wait for the end geess Retrieving Results CALC LIM FAIL Queries the result of the limit check Result 0 passed TRAC DATA LIST Programming Examples R amp S FSW K91 Retrieves the peak list of the spectrum emission mask measurement Result 1 000000000 1 275000000E 007 8 500000000E 006 8 057177734E 00 2 000000000 8 500000000E 006 7 500000000E 006 8 158547211E 001 3 000000000 7 500000000E 006 3 500000000E 006 4 202708435E 00 ks Table 10 17 Trace results for SEM measurement 77 882799530E 00 77 984169006E 001 74 028330231E 00 72 982799530E 73 084169006E 7 5 270565033 4 00 001 000000000E 006 0 000000000 0
56. Manual How to Determine the OBW SEM ACLR or CCDF for WLAN Signals 6 Select the Display Config button and select the evaluation methods that are of interest to you Arrange them on the display to suit your preferences 7 Exit the SmartGrid mode and select the Overview softkey to display the Over view again 8 Select the Analysis button in the Overview to make use of the advanced analy sis functions in the result displays e Configure a trace to display the average over a series of sweeps if necessary increase the Sweep Count in the Sweep settings e Configure markers and delta markers to determine deviations and offsets within the evaluated signal e Use special marker functions to calculate noise or a peak list e Configure a limit check to detect excessive deviations 9 Optionally export the trace data of the graphical evaluation results to a file a Inthe Traces tab of the Analysis dialog box switch to the Trace Export tab b Select Export Trace to ASCII File c Define a file name and storage location and select OK 9 9 1 9 1 1 Optimizing the Measurement Results Optimizing and Troubleshooting the Mea surement e Optimizing the Measurement Resuhts nnn nnnnnneene ne 164 e Error Messages and Watrnlhgs cete erede ENEE to fr Ru RR 165 Optimizing the Measurement Results If the results do not meet your expectations try the following methods to optimize the measurement
57. OPERation NTRansition lt SumBit gt STATus QUEStionable NTRansition lt SumBit gt STATus QUEStionable ACPLimit NTRansition lt SumBit gt lt ChannelName gt STATus QUEStionable LIMit lt n gt NTRansition lt SumBit 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 The parameter is optional If you omit it the command works for the currently active channel 10 11 3 6 10 12 Commands for Compatibility Controlling the Positive Transition Part STATus OPERation PTRansition lt SumBit gt STATus QUEStionable PTRansition lt SumBit gt STATus QUEStionable ACPLimit PTRansition lt SumBit gt lt ChannelName gt STATus QUEStionable LIMit lt n gt PTRansition lt SumBit gt lt ChannelName gt STATus QUEStionable SYNC PTRansition lt BitDefinition gt lt ChannelName gt These 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 registe
58. OTYPe on page 212 Level Output Type Trigger 2 3 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 212 Pulse Length Output Type Trigger 2 3 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 213 Send Trigger Output Type Trigger 2 3 Sends a user defined trigger to the output connector immediately Note that the trigger 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 213 5 3 5 3 MIMO Capture Settings The following settings are only available for the IEEE 802 11ac and n standards WLAN IQ Measurement Modulation Accuracy Flatness Tolerance WLAN um Signal Capture Trigger Source Trigger In Out MIMO Capture DUT MIMO Config 1 Tx Antenna MIMO Antenna Signal Capture Setup Simultaneous Sequential using OSP Switch Box E Sequential Manual Simultaneous Signal Capture Setup using 1 Rx Channel s e sa Guid piiois mmm anemona 2 93 T 4 M J
59. PPDUS eeeeeeeeeeneeeneeeenen nnne nnne nnns 76 4 6 Demodulation Parameters Logical Filters eee 77 4 7 Receiving Data Input and Providing Data Output eee 78 4 8 Preparing the R amp S FSW for the Expected Input Signal Frontend Parameters 79 4 9 Triggered measurements cesses nennen enne nn nnne n nenne nnn nennen 80 LEE descr eee 85 5 1 Multiple Measurement Channels and Sequencer Function 85 5 2 Display Configuration etit titer nc RR EUR eens 87 5 3 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 87 5 4 Frequency Sweep Measurements esee EEN 147 SP np e c r 151 7 IQ Data Import and EXPO iniciaci n 152 71 1 Import Export F nctlOns erer nerit toe ERR ERRRR RN R RS RARE RAREARKRRKRRRRNRRARRERERURRRRRRENRARA RBS 152 7 2 How to Export and Import UO Data eceeeeeeeeeeeeeeseeeeenen nennen 153 User Manual 1173 9357 02 11 3 R amp S FSW K91 8 2 8 3 9 1 9 2 10 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 A 1 A 2 Contents How to Perform Measurements in the WLAN Application 156 How to Determine Modulation Accuracy Flatness and Tolerance Parameters for WLAN ELA AA N A REER ENAE EE
60. Phase drift and frequency deviation The common phase drift in FFT is given by phase 27xN I N x Af rest Txl dy Common phase drift 4 2 with e N 80 the number of Nyquist samples of the symbol period e N 64 the number of Nyquist samples of the useful part of the symbol e A fesi the not yet compensated frequency deviation e dY the phase jitter at the symbol In general the coarse frequency estimate A coarse see figure 4 1 is not error free Therefore the remaining frequency error Al represents the frequency deviation in rik not yet compensated Consequently the overall frequency deviation of the device under test DUT is calculated by Af Af coarse ES Afrest The common phase drift in Common phase drift is divided into two parts to calculate the overall frequency deviation of the DUT The reason for the phase jitter dy in Common phase drift may be different The nonlin ear part of the phase jitter may be caused by the phase noise of the DUT oscillator Another reason for nonlinear phase jitter may be the increase of the DUT amplifier temperature at the beginning of the PPDU Note that besides the nonlinear part the phase jitter dy also contains a constant part This constant part is caused by the fre quency deviation A f est not yet compensated To understand this keep in mind that the measurement of the phase starts at the first symbol 1 of the payload In contrast the channel frequency respons
61. Pilot bit error rate BPILot EVM all carriers SEACarriers EVM data carriers SEDCarriers EVM pilot carriers SEPCarriers Table 10 9 Parameters for the items of the Result Summary Global Result in table SCPI parameter Pilot bit error rate PBERate EVM all carriers EACarriers EVM data carriers EDCarriers EVM pilot carriers EPCarriers 10 7 4 10 7 5 Configuring the Result Display Result in table SCPI parameter Center frequency error CFERror Symbol clock error SCERror Configuring the Spectrum Flatness and Group Delay Result Dis plays The following command is only relevant for the Spectrum Flatness and Group Delay result displays CONFigure BURSt SPECtrum FLATness CSELect lt ChannelType gt This remote control command configures the Spectrum Flatness and Group Delay results to be based on either effective or physical channels This command is only valid for IEEE 802 11n and IEEE 802 11ac standards While the physical channels cannot always be determined the effective channel can always be estimated from the known training fields Thus for some PPDUs or mea surement scenarios only the results based on the mapping of the space time stream to the Rx antenna effective channel are available as the mapping of the Rx antennas to the Tx antennas physical channel could not be determined For more information see chapter 4 3 3 Physical vs Effective Channels on page 70
62. Q channel Such signals are referred to as UO signals UO 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 UO baseband Importing and exporting UO signals is useful for various applications e Generating and saving UO signals in an RF or baseband signal generator or in external software tools to analyze them with the R amp S FSW later e Capturing and saving l Q signals with an RF or baseband signal analyzer to ana lyze them with the R amp S FSW or an external software tool later For example you can capture UO data using the I Q Analyzer application if available and then perform a WLAN 802 11 measurement on that data later using the R amp S FSW WLAN 802 11 application As opposed to storing trace data which may be averaged or restricted to peak values UO data is stored as it was captured without further processing The data is stored as complex values in 32 bit floating point format Multi channel data is not supported The UO data is stored in a format with the file extension iq tar For a detailed description see the R amp S FSW UO Analyzer and UO Input User Manual MOOV Export PUNCUONS seeders eee ere Pa edet tenet t e ep ees 152 e How to Export and Import VQ Data 153 Import Export Functions The following import and export functions are available via softkeys i
63. RF Atten Auto su 105 RF Atten Manual sie 105 inse 111 SOQUENCO ita OS 86 Signal Capture 107 Gite IWER le LEE EN Single SEQUENCES E 86 Single Sweep 146 Sweep Config 146 SWEEP COUNT 146 Du EE 111 Trigger Config 108 Trigger Offset Upper Level Hysteresis AA 145 Space Time Block Coding H NEE 130 136 Spacetime Steam errar a 70 Span VIT ERE 87 Spatial mapping mode MIMO ME 138 User defined MIMO AAA 139 Specifics for E ele LTE 90 Spectrum Emission Mask A 49 Spectrum Flatness Parameters irren ec rec rue erat Result display Trace data consi c e teneret ees Standard see Digital Standard viii iaa 11 Standard WLAN measurements sssssssss 13 Starting WLAN application Statistic count cuc Statistics Te UE 16 Programming example S Status Dat ciens 22 12 Error messages E 165 Status registers EL QUO RVING ie torte ds STAT QUESIPOW ind tn o reitera n deg STATus QUEStionable DIQ STATus QUEStionable SYNC E STBC PPDUS centies ath PPDUS remote nete enter Suffixes Eu TEE 167 Remote commands tr rr era enc 169 OU creyem 108 sc EE 203 Sweep ABDOMINO i c eno cot nia 146 Configuration remote iriiria 244 Configuration softkey AA 146 COUNT ees ON 146 ife MEMOS EE 203 Symbol
64. Range 0 5V to 3 5 V RST 1 4 V Example TRIG LEV 2V Manual operation See Trigger Level on page 113 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 For details on the trigger settings see Trigger Source Settings on page 109 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 113 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance TRIGger SEQuence LEVel IQPower lt TriggerLevel gt This command defines the magnitude the 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 For details on the trigger source see Trigger Source Settings on page 109 Parameters lt TriggerLevel gt Range 130 dBm to 30 dBm RST 20 dBm Example TRIG LEV Top 30DBM Manual operation See Trigger Level on page 113 TRIGger SEQuence LEVel POWer AUTO lt State gt By default the optimum trigger level for power triggers is automatically measured and determined at th
65. Ri A TO ele le EE Tracking IEEE 802 11a g OFDM 58 Phase Error vs Preamble A tee ees ee eer 35 Phase tracking i Pilot bit error rate Pilots TOR MACK A O TO Polynomial degree AM AM cocccccccccnnnonnnnnononnnconnnnnonnnnnnnnnnnnononnnnonnnnnnnnnnnnnno 144 Power Interval search oococooocccccnccconoconoconoccnnnonnnnnnnccnnnnnnnnnos 121 PPDU na 13 EC We 31 vs time see PVT 97 38 39 Power interval search oooooccccccnococccncccccononannononocononnanonono 217 Power normalize MMO ecc eege 138 Power sensors MIG GSP ue PRO 112 PPDU ADDIGVIAU ON e ucro rt ined 62 Amount to analyze 140 235 Amount to analyze remote ssssss 234 Analysis mode 125 127 134 Analyzed MR 11 76 Channel bandwidth 125 126 128 132 134 135 225 Gount remote tc deo tdeo drei 262 Currently analyzed 2x9 15 Nues TO le TEE 124 Displayed E 11 EVM KE EE 20 Extension Spatial Streams IEEE 802 11 n 136 220 epp iore c rs 125 128 132 134 Format default EE 88 Format remote 2 neto deed Sonny 227 228 Guard interval length IEEE 802 11 n ac 131 137 Bue UE Level errors Maximum length remote ssessse 238 Minimum length remote AAA 238 Modulation 126 228 Modulation IEEE 802 11 a
66. S FSW8 13 15dB and 30 dB R amp S FSW26 or higher 30 dB All other values are rounded to the nearest of these two RST OFF Example INP GAIN VAL 30 Switches on 30 dB preamplification Usage SCPI confirmed Manual operation See Preamplifier option B24 on page 106 INPut GAIN STATe lt State gt This command turns the preamplifier on and off The command requires option R amp S FSW B24 This function is not available if the Digital Baseband Interface R amp S FSW B17 is active Parameters lt State gt ON OFF RST OFF Example INP GAIN STAT ON Switches on 30 dB preamplification Usage SCPI confirmed Manual operation See Preamplifier option B24 on page 106 Signal Capturing The following commands are required to configure how much and how data is captured from the input signal 10 5 4 1 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance e General Capture Settings c teccaceceescsepeessecsseneesecccnaeessetersseesentdaeredeectaqaeesenees 203 e Configuring Triggered Measurements nnan 204 e MIMO Capture Seting nene anida ads KEE idee 213 General Capture Settings ISENGeIDANDwOdTRE Solution Fi Ter STATel een 203 EN eaa ar utet dude lmed toa ima tede c ted UL EE 203 SENGES tee 203 RRE EO NK 204 SENSe BANDwidth RESolution FILTer STATe lt State gt This remote control command enables or disables use of the adjacent channel filter If activated
67. Sample Rate 10 0 MHz Auto KEE Full Scale Level IQR100 101165 Digital IQ OUT 10 MHz 10 dBm For more information see the R amp S FSW l Q Analyzer and UO Input User Manual Digital VQ Weier 95 atelier 95 SS A O nat en 95 Adjust Reference Level to Full Scale Level 96 Connected nstume ooo teen et E Tao 96 BMG 6620 y 0 e OCC PI E E NE E OET 96 Digital UO Input State Enables or disable the use of the Digital IQ input source for measurements Digital IQ is only available if the Digital Baseband Interface R amp S FSW B17 is installed Remote command INPut SELect on page 187 Input Sample Rate Defines the sample rate of the digital UO signal source This sample rate must corre spond with the sample rate provided by the connected device e g a generator If Auto is selected the sample rate is adjusted automatically by the connected device The allowed range is from 100 Hz to 10 GHz Remote command INPut DIQ SRATe on page 191 INPut DIQ SRATe AUTO on page 191 Full Scale Level The Full Scale Level defines the level and unit that should correspond to an UO sam ple with the magnitude 1 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance If Auto is selected the level is automatically set to the value provided by the connec ted device Remote command INPut DIQ RANGe UPPer on page 190 INPut DIQ RANGe UPPer UNIT on page 191 INPut DIQ RANGe UPPer
68. Selected WLAN measurement standard Meas Setup Number of Transmitter Tx and Receiver Rx channels used in the mea surement for MIMO Capt time No of Samples Duration of signal capture and number of samples captured No of Data Symbols The minimum and maximum number of data symbols that a PPDU may have if it is to be considered in results analysis Analyzed PPDUs x of y z For statistical evaluation over PPDUs see PPDU Statistic Count No of PPDUs to Analyze on page 140 lt x gt PPDUs of totally required lt y gt PPDUs have been analyzed so far lt z gt PPDUs were analyzed in the most recent sweep 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 FSW Getting Started manual Window title bar information For each diagram the header provides the following information 2 Magnitude Capture Fig 2 1 Window title bar information in the WLAN application 1 Window number 2 Window type 3 Trace color 4 Trace number 6 Trace mode Understanding the Display Information Diagram footer information The diagram footer beneath the diagram contains the start and stop values for the displaye
69. 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 tenance instrument interfaces and troubleshooting 1 3 1 3 1 Conventions Used in the Documentation 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 ters refer to the data sheets Basic information on operating the R amp S FSW is not inclu ded in the application manuals All user manuals are also available for download from the Rohde amp Schwarz website on the R amp S FSW product page at http www2 rohde schwarz com product FSW 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 FSW 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 fo
70. Using Electronic Attenuation Option B25 on page 105 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 is only available with option R amp S FSW B25 This function is not available if the Digital Baseband Interface R amp S FSW B17 is active Parameters State ON OFF 0 1 RST 1 Example INP EATT AUTO OFF Manual operation See Using Electronic Attenuation Option B25 on page 105 INPut EATT STATe lt State gt This command turns the electronic attenuator on and off This command is only available with option R amp S FSW B25 This function is not available if the Digital Baseband Interface R amp S FSW B17 is active Parameters lt State gt ON OFF RST OFF 10 5 4 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Example INP EATT STAT ON Switches the electronic attenuator into the signal path Manual operation See Using Electronic Attenuation Option B25 on page 105 INPut GAIN VALue lt Gain gt This command selects the preamplification level if the preamplifier is activated INP GAIN STAT ON see INPut GAIN STATe on page 202 The command requires option R amp S FSW B24 Parameters lt Gain gt 15 dB 30 dB The availability of preamplification levels depends on the R amp S FSW model R amp
71. WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Fig 3 3 Negative gain imbalance Quadrature Offset An ideal UO modulator sets the phase angle between the and Q path mixer to exactly 90 degrees With a quadrature offset the phase angle deviates from the ideal 90 degrees the amplitudes of both components are of the same size In the vector dia gram the quadrature offset causes the coordinate system to shift A positive quadrature offset means a phase angle greater than 90 degrees Fig 3 4 Positive quadrature offset A negative quadrature offset means a phase angle less than 90 degrees WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Fig 3 5 Negative quadrature offset 3 1 1 4 I Q Skew If transmission of the data on the path is delayed compared to the Q path or vice versa the UO data becomes skewed The I Q skew results are currently not measured directly but can be compensated for together with Gain Imbalance and Quadrature Offset see UO Mismatch Compensa tion on page 123 3 1 1 5 UO Mismatch UO mismatch is a comprehensive term for Gain Imbalance Quadrature Offset and UO Skew Compensation for UO mismatch is useful for example if the device under test is known to be affected by these impairments but the EVM without these effects is of interest Note however that measurements strictly according to IEEE 802 11 2012 IEEE P802 11ac D5 0 WLAN standard may no
72. a trigger is detected again Parameters lt DropoutTime gt Dropout time of the trigger Range Osto10 0s RST Os Manual operation See Drop Out Time on page 113 TRIGger SEQuence HOLDoff TIME lt Offset gt Defines the time offset between the trigger event and the start of the sweep data cap turing Parameters lt Offset gt RST Os Example TRIG HOLD 500us Manual operation See Trigger Offset on page 113 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance TRIGger SEQuence IFPower HOLDoff Period 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 Parameters Period Range Os to 10s RST 0s 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 114 TRIGger SEQuence IFPower HYSTeresis lt Hysteresis gt This command defines the trigger hysteresis which is only available for IF Power trig ger sources Parameters lt Hysteresis gt Range 3 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 114 TRIGger SEQuence LEVel BBPower lt Level gt This command sets the level of the baseband po
73. amp S FSW B71 is installed Remote command INPut SELect on page 187 UO Mode Defines the format of the input signal jQ The input signal is filtered and resampled to the sample rate of the application Two inputs are required for a complex signal one for the in phase component and one for the quadrature component WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Only Low IF I The input signal at the BASEBAND INPUT I connector is filtered and resampled to the sample rate of the application If the center frequency is set to 0 Hz the real baseband signal is dis played without down conversion Real Baseband l If a center frequency greater than 0 Hz is set the input signal is down converted with the center frequency Low IF 1 Q Only Low IF Q The input signal at the BASEBAND INPUT Q connector is filtered and resampled to the sample rate of the application If the center frequency is set to 0 Hz the real baseband signal is dis played without down conversion Real Baseband Q If a center frequency greater than 0 Hz is set the input signal is down converted with the center frequency Low IF Q Remote command INPut IQ TYPE on page 193 Input configuration Defines whether the input is provided as a differential signal via all 4 Analog Baseband connectors or as a plain UO signal via 2 simple ended lines Note Both single ended and differential probes are supported as input howev
74. attenuation from the reference level Usage SCPI confirmed Manual operation See Attenuation Mode Value on page 105 INPut ATTenuation AUTO lt State gt This command couples or decouples the attenuation to the reference level Thus when the reference level is changed the R amp S FSW determines the signal level for optimal internal data processing and sets the required attenuation accordingly This function is not available if the Digital Baseband Interface R amp S FSW B17 is active Parameters lt State gt ON 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 105 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 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 on page 201 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 is only available with option R amp S FSW B25 This function is not available if the Digital Baseband Interface R amp S FSW B17 is active Parameters lt Attenuation 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
75. be performed once INIT SEQ IMM Starts the sequential measurements Manual operation See Sequencer Mode on page 86 Retrieving Results SYSTem SEQuencer lt State gt 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 FSW User Manual Parameters lt State gt ON 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 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 Manual operation See Sequencer State on page 86 Retrieving Results The following commands are required to retrieve the results from a WLAN measure ment in a remote environment Before retrieving measurement results check if PPDU synchronization was successful or not by checking the status register see chapter 10 11 1 The STATus QUEStiona ble SYNC Register on page 293 If no PPDUs were found STAT QUES SYNC COND returns O see STATus QUEStiona
76. be aborted by selecting the highlighted softkey or key again Frequency Sweep Measurements 5 4 Frequency Sweep Measurements When you activate a measurement channel in WLAN mode an IQ measurement of the input signal is started automatically see chapter 3 1 WLAN UO Measurement Modu lation Accuracy Flatness and Tolerance on page 13 However some parameters specified in the WLAN 802 11 standard require a better signal to noise level or a smaller bandwidth filter than the default measurement on UO data provides and must be determined in separate measurements based on RF data see chapter 3 2 Fre quency Sweep Measurements on page 47 In these measurements demodulation is not performed Selecting the measurement type WLAN measurements require a special operating mode on the R amp S FSW which you activate using the MODE key on the front panel gt To select a frequency sweep measurement type do one of the following e Select the Overview softkey In the Overview select the Select Measure ment button Select the required measurement e Press the MEAS key on the front panel In the Select Measurement dialog box select the required measurement The R amp S FSW WLAN application uses the functionality of the R amp S FSW base system Spectrum application to perform the WLAN frequency sweep measurements Some parameters are set automatically according to the WLAN 802 11 standard the first time a measurement is select
77. ccsssdecccccctesssattenrdeasnssavacesccarasdeondacrgansesnaanadss 36 PYT MP EE 37 PVT RISING EE 38 PVE Fao BOGS EE 39 Result Summary Detalled ueeceee eee raptae eene tene enhance nn ppt tha Rte pen ERES ED una 40 Result Summary Global 2 crt ertt ttt tritt EE dd 41 Signal teeeeety 43 Spectrum Ee corrente REM Re R SNR EAUR ARE RENS AKAER EREMN QE a ME eMe ed E Ne dneeK RENE RRdE 46 R amp S FSW K91 Measurements and Result Displays AM AM This result display shows the measured and the reference signal in the time domain For each sample the x axis value represents the amplitude of the reference signal and the y axis value represents the amplitude of the measured signal The reference signal is derived from the measured signal after frequency and time syn chronisation channel equalization and demodulation of the signal The equivalent time domain representation of the reference signal is calculated by reapplying all the impair ments that have been removed prior to demodulation The trace is determined by calculating a polynomial regression model of a specified degree see chapter 5 3 10 3 AM AM Configuration on page 144 for the scattered measurement vs reference signal data The resulting regression polynomial is indica ted in the window title of the result display Note The measured signal and reference signal are complex signals This result display is not available for sin
78. chapter 5 3 4 Input and Frontend Settings on page 92 4 Signal Capture See chapter 5 3 5 Signal Capture Data Acquisition on page 107 5 Synchronization OFDM demodulation See chapter 5 3 6 Synchronization and OFDM Demodulation on page 121 6 Tracking Channel Estimation See chapter 5 3 7 Tracking and Channel Estimation on page 122 7 Demodulation See chapter 5 3 8 Demodulation on page 124 8 Evaluation Range See chapter 5 3 9 Evaluation Range on page 139 9 Display Configuration See chapter 5 2 Display Configuration on page 87 To configure settings gt 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 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 on the front panel restores the entire instrument to its default values and thus closes all measurement channels on the R amp S FSW except for the default Spectrum application channel See chapter 5 3 1 Default Settings for WLAN Measurements on page 88 for details Remote command SYSTem PRESet CHANnel EXECute on page 177 Select Measurement Selects a measurement to be performed See Selecting the measurement type on
79. clock t 13 error limit remote suce wen cot erii 241 Error limit check result remote 271 Symbols Count remote EE 262 Bri ee 59 Long IEEE 802 11a g OFDM 56 Short IEEE 802 11a g OFDM 00 SYNCHTONIZAION siii 121 Remote CONE siii nic 217 T Time trigger Repetitioniinterval dotarse ias 113 Ec Tears 111 Timing COARSE gon M 56 Detection IEEE 802 11a g OFDM 56 Deviations oooooooccccccnoccoocccnccconananonnnnnon 2 99 Fine sa 06 ele le icio ca crt roo p itus sy 123 Tracking IEEE 802 11a g OFDM 58 Timing emor tracking eere tueretur tuae toy opere rea 220 Tolerance Parameters occococococonncononononnnnnocononnnnnnnnnnnnnononnnnnncnnnnnnnns 13 Traces ele TE 22 Results remote 276 PACKING iia ainia 58 NC 88 Level errors 219 Phase drift E 123 219 PIOUS EE 123 219 Remote control Alle RTE Trigger Configuration remote Configuration softkey A BICI S Drop out TIME cosmos Drop Qut TIME 2 rte rre rre tnnt 81 External Femolte icr ctos 209 Holdoff 82 114 Hysteresis 81 114 Hl 113 MeasU remiehts rettet ree ec er n 80 OSE E 80 Offset SOftKGy corria cr aa 113 QU PUE asias 99 114 SlODO nae 114 209 Synchronization inicios 83 Trigger
80. decoded data from the Signal field of each recognized PPDU This field contains information on the modulation used for transmission This result display is not available for single carrier measurements IEEE 802 11b g DSSS use PLCP Header IEEE 802 11b g GSSS instead 2 Signal Field Format MCS CBW HT SIG Len Sym SNRA STBC GI Ness Alst Alst Alst Estimated Alst Alst T MF 2 40 T MF TU f Fig 3 26 Signal Field display for IEEE 802 11n The signal field information is provided as a decoded bit sequence and where appro priate also in human readable form beneath the bit sequence for each PPDU The currently applied demodulation settings as defined by the user see chapter 5 3 8 Demodulation on page 124 are indicated beneath the table header for reference Since the demodulation settings define which PPDUs are to be analyzed this logical filter may be the reason if the Signal Field display is not as expected Table 3 5 Demodulation parameters and results for Signal Field result display IEEE 802 11a g OFDM p Parameter Description Format PPDU format used for measurement Not part of the IEEE 802 11a g OFDM p signal field displayed for convenience see PPDU Format to measure on page 125 CBW Channel bandwidth to measure Not part of the signal field displayed for conven ience Rate Mbit s Symbol rate per second R Reserved bit Length Sym Human readable length of payloa
81. display Remote command LAY ADD WIND 2 RIGH PRIS see LAYout ADD WINDow on page 248 or CONFigure BURSt PVT SELect on page 180 CONFigure BURSt PVT IMMediate on page 180 PvT Falling Edge Displays the minimum average and maximum power vs time diagram for the falling edge of all PPDUs 2 PVT Rising Fig 3 22 PvT Falling Edge result display Remote command LAY ADD WIND 2 RIGH PFAL see LAYout ADD WINDow on page 248 or CONFigure BURSt PVT SELect on page 180 CONFigure BURSt PVT IMMediate on page 180 User Manual 1173 9357 02 11 39 R amp S FSW K91 Measurements and Result Displays Result Summary Detailed The detailed result summary contains individual measurement results for the Transmit ter and Receiver channels and for the bitstream This result display is not available for single carrier measurements IEEE 802 11b g DSSS 3 Result Summary Detailed Ses m1 2 tream 1 tream 2 3 1Rx1 Tx 1 Limit Mean Mean Stream 1 Stream Mean Limit Mean Limit Fig 3 23 Detailed Result Summary result display for IEEE 802 11n MIMO measurements The Result Summary Detailed contains the following information Note You can configure which results are displayed see chapter 5 3 10 Result Con figuration on page 142 However the results are always calculated regardless of their visibility Tx channel Tx All e 1 Q offset dB e Gain imbalance dB e Quadrature offse
82. essere nenennn inrer trn nni 290 EBEN 290 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 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 sweeps See also INI Tiate CONTinuous on page 258 Return values lt Result gt Result at the marker position R amp S9FSW K91 Example Usage Manual operation Remote Commands for WLAN Measurements p M A Qw 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 Outputs the measured value of marker 2 Query only See CCDF on page 50 See Marker Table on page 52 See Marker Peak List on page 52 10 10 2 Zooming into the Display 10 10 2 1 Using the Single Zoom DISPlay WINDow lt n gt ZOOM AREA DISPlay WINDow lt n gt ZOOM STATe DISP
83. first PPDU The format modulation of the first valid PPDU is detected and subse quent PPDUs are analyzed only if they have the same format Auto individually for each PPDU All PPDUs are analyzed regardless of their format modulation Meas only Only PPDUs with the specified format or PSDUs with the specified modulation are analyzed 5 3 8 4 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Demod all as All PPDUs are assumed to have the specified PPDU format PSDU modulation Remote command SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 SENSe DEMod FORMat BANalyze on page 227 SENSe lt n gt DEMod FORMat SIGSymbol on page 232 PPDU Format If analysis is restricted to PPDUs with a particular format see PPDU Format to mea sure PSDU Modulation to use this setting defines which type For details on supported modulation depending on the standard see table 4 1 Remote command SENSe DEMod FORMat BANalyze on page 227 SENSe DEMod FORMat BANalyze BTYPe on page 301 PSDU Modulation If analysis is restricted to PSDU with a particular modulation type this setting defines which type For details on supported modulation depending on the standard see table 4 1 Remote command SENSe DEMod FORMat BANalyze on page 227 Demodulation IEEE 802 11n The following settings are available for demodulation of IEEE 802 11n signals De
84. for the FFT conversion An Offset can be defined to delay the measurement after the trigger event or to include data before the actual trigger event in time domain measurements pre trigger offset For complex tasks advanced trigger settings are available e Hysteresis to avoid unwanted trigger events caused by noise e Holdoff to define exactly which trigger event will cause the trigger in a jittering sig nal Nuet EE 80 e Trigger PYSteresiS iicinccnnnc e deca 81 e Tagger Drop OUt Hun 81 e THgger Hold EE 82 e Trigger Synchronization Using an R amp S FS Z11 Trigger Unit 83 4 9 1 Trigger Offset An offset can be defined to delay the measurement after the trigger event or to include data before the actual trigger event in time domain measurements pre trigger offset Pre trigger offsets are possible because the R amp S FSW captures data continuously in the time domain even before the trigger occurs See Trigger Offset on page 113 Triggered measurements 4 9 2 Trigger Hysteresis Setting a hysteresis for the trigger helps avoid unwanted trigger events caused by noise for example The hysteresis is a threshold to the trigger level that the signal must fall below on a rising slope or rise above on a falling slope before another trigger event occurs Example In the following example the second possible trigger event is ignored as the signal does not exceed the hysteresis threshold
85. how the data is measured Sweep UNIT d PET 146 IR een lee EE CR o KEE 146 single Sweep RUN SINGLE coo ol troppe 146 Continue SINGS SWOOP xcti S amet aes 146 Sweep Count This setting is currently ignored For statistical evaluation see PPDU Statistic Count No of PPDUs to Analyze on page 140 Continuous Sweep RUN CONT While the measurement is running the Continuous Sweep softkey and the RUN CONT key are 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 Note Sequencer Furthermore the RUN CONT key controls the Sequencer not indi vidual sweeps RUN CONT starts the Sequencer in continuous mode Remote command INITiate CONTinuous on page 258 Single Sweep RUN SINGLE 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 Note Sequencer Furthermore the RUN SINGLE key controls the Sequencer not individual sweeps RUN SINGLE starts the Sequencer in single mode If the Sequencer is off only the evaluation for the currently displayed measurement channel is updated Remote command INITiate IMMediate on page 259 Continue Single Sweep While the measurement is running the Continue Single Sweep softkey and the RUN SINGLE key are highlighted The running measurement can
86. in WLAN signal descrip tion see Standard on page 91 Number of adjacent channels 3 Reference channel Max power Tx channel Channel bandwidth 20 MHz For further details about the ACLR measurements refer to Measuring Channel Power and Adjacent Channel Power in the R amp S FSW User Manual To restore adapted measurement parameters the following parameters are saved on exiting and are restored on re entering this measurement e Reference level and reference level offset e RBW VBW e Sweep time e Span e Number of adjacent channels e Fast ACLR mode The main measurement menus for the frequency sweep measurements are identical to the Spectrum application Spectrum Emission Mask The Spectrum Emission Mask measurement shows the quality of the measured signal by comparing the power values in the frequency range near the carrier against a spec tral mask that is defined by the WLAN 802 11 specifications The limits depend on the selected power class Thus the performance of the DUT can be tested and the emis sions and their distance to the limit are identified 0 Note that the WLAN standard does not distinguish between spurious and spectral emissions The Result Summary contains a peak list with the values for the largest spectral emis sions including their frequency and power The WLAN application performs the SEM measurement as in the Spectrum application with the following settings Frequency Sweep Measu
87. is performed for multiple antennas Parameters lt State gt ON OFF ON RX antennas are synchronized and tracked together OFF RX antennas are synchronized and tracked separately RST OFF Manual operation See Joined RX Sync and Tracking on page 118 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 10 5 5 Synchronization and OFDM Demodulation SENSE DEMOd ERTFOPESEL coin 217 Ei ERT ag ET 217 SENSe DEMod FFT OFFSet lt Mode gt This command specifies the start offset of the FFT for OFDM demodulation not for the FFT Spectrum display Parameters lt Mode gt AUTO GlCenter PEAK AUTO The FFT start offset is automatically chosen to minimize the intersymbol interference GlCenter Guard Interval Center The FFT start offset is placed to the cen ter of the guard interval PEAK The peak of the fine timing metric is used to determine the FFT start offset RST AUTO Manual operation See FFT Start Offset on page 121 SENSe DEMod TXARea lt State gt If enabled the R amp S FSW WLAN application initially performs a coarse burst search on the input signal in which increases in the power vs time trace are detected Further time consuming processing is then only performed where bursts are assumed This improves the measurement speed for signals with low duty cycle rates However for signals in which the PPDU power levels differ significantly this option should be disabled as
88. level AUTO Sex bv dca re teste eter ro hated ie e intere 113 Auto 6mol amp EEN External trigger remote VQ Power remote emet IFSPower remote crece toda terat RF Power remote Trigger source BB Power Digital 1 Q External seg RN EE 110 VQ POWER EE 111 IF Power 110 Power Sensor vs 112 RF Power sod Time ese s 111 Troubleshooting 164 Inp t ov rload mmm nis 186 U Units cuc 268 Gain imbalance results 268 PPDU length results 268 Reference level 104 Upper Level Hysteresis led Pn 145 Usable UO bandwidth PCT OMI ecc 307 ISS manuals eegener eeneg 6 User sample rate JB TATUM n e e 307 Ww Window title bar 2 2 cecceeeeseeeeeeeceeeeceeeeeeeeseeaeeeeenaeeess 11 Windows Adding BCEE 248 Closing remote seen 251 254 Config ring ur orent rer reete rens 90 Layout remote 252 Maximizing remote tere 247 Querying remote 250 251 Replacing remote ree ue 251 Splitting remote valium 247 Types remote dcr get iet end 248 WLAN Me as remients cnr tre ren red 13 Measurements step by step 156 Parameters nere zh Programming examples 902 Remote control 167 Crac M 13 Y YIG preselector Activating Deactivating s Activating Deactivating remote e BA M Z Zooming
89. measurement channel is created which deter mines the measurement settings for that application These settings include the input source the type of data to be processed I Q or RF data frequency and level settings measurement functions etc If you want to perform the same measurement but with dif ferent center frequencies for instance or process the same input data with different measurement functions there are two ways to do so e Change the settings in the measurement channel for each measurement scenario In this case the results of each measurement are updated each time you change the settings and you cannot compare them or analyze them together without stor ing them on an external medium e Activate a new measurement channel for the same application In the latter case the two measurement scenarios with their different settings are displayed simultaneously in separate tabs and you can switch between the tabs to compare the results For example you can activate one WLAN measurement channel to perform a WLAN modulation accuracy measurement and a second channel to perform an Multiple Measurement Channels and Sequencer Function SEM measurement using the same WLAN input source Then you can monitor all results at the same time in the MultiView tab 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 on the R amp S FSW at any t
90. measurements in the R amp S FSW WLAN application in a remote environment It is assumed that the R amp S FSW has already been set up for remote control in a net work as described in the R amp S FSW User Manual o Note that basic tasks that are independant of the application are not described here For a description of such tasks see the R amp S FSW User Manual In particular this includes e Managing Settings and Results i e storing and loading settings and result data e Basic instrument configuration e g checking the system configuration customizing the screen layout or configuring networks and remote operation e Using the common status registers After an introduction to SCPI commands the following tasks specific to the WLAN application are described here e Common Err 167 LENS eec s 168 Activating WLAN Measurements nnne eet bna ttn Res e ak nnn ERR Ra 173 e Selecting a Measuremlent iiiiieeeiiieceeeeiece cient ce e tei none Eo Etant ERR nnde Enn 177 e Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Toler BINGO 184 e Configuring Frequency Sweep Measurements on WLAN Signals 245 e Configuring the Result Display 247 e Staring a Measurement cereos ata 257 e Retrieving Res lls erre dera 261 EE 289 e Status EE 293 e Commands for Compatibility 2 cocer tere tired ia 3
91. number of TX antennas data will be transmitted from b Under MIMO antenna Signal Capture Setup select Sequential using OSP switch box c Enter the IP address of the connected OSP switch box d For the OSP Switch Bank Configuration select the module used to connect the OSP switch box to the R amp S FSW e Connect the antennas and the R amp S FSW to the OSP switch box as indicated in the dialog box f Configure the OSP switch box to switch between the antenna input as required 8 To define a particular starting point for the FFT or to improve the measurement speed for signals with a low duty cycle select the Synchronization OFDM Demod button and set the required parameters 9 Select the Tracking Channel Estimation button to define how the data channels are to be estimated and which distortions will be compensated for e g crosstalk between the MIMO antennas at the DUT 10 Select the Demod button to provide information on the modulated signal and how the PPDUs detected in the capture buffer are to be demodulated 11 Select the MIMO tab in the Demodulation dialog box to define which spatial mapping mode is used that is how the space time streams are mapped to the antennas User Manual 1173 9357 02 11 159 How to Analyze WLAN Signals in a MIMO Measurement Setup a If necessary include a time shift for the individual antennas b Ifthe signal power is amplified according to the maxtrix entries so that t
92. of the signal power to be included in the bandwidth measurement can be changed The occupied bandwidth is indicated as the Occ BW function result in the marker table the frequency markers used to determine it are also displayed EECH User Manual 1173 9357 02 11 49 R amp S FSW K91 Measurements and Result Displays Ref Level 0 00 dBm 2 RBW 3 z SGL Att 10 dB SWT 1 ms VBW 300kHz Mode Auto FFT 1 Occupied Bandwidth 1Rm Clin CF 2 1 GHz 1001 pts 1 15 MHz Span 11 52 MHz 2 Marker Table Type Ref Tre Stimulus Response Funetion Function Result Mi 1 2 09963 GHz 27 37 dBm 1 1 SHZ 32 78 dBm oc Bw 4 166073926 MHz T2 1 2 15 GH 33 12 dBm For details see chapter 5 4 3 Occupied Bandwidth on page 149 Remote command CONFigure BURSt SPI Querying results CALC MARK FUNC POW RES OBW see CALCulate MARKer FUNCtion POWer lt sb gt RESult on page 273 trum OBWidth IMMediate on page 183 E E CCDF The CCDF complementary cumulative distribution function measurement determines the distribution of the signal amplitudes The measurement captures a user definable amount of samples and calculates their mean power As a result the probability that a sample s power is higher than the calculated mean power x dB is displayed The crest factor is displayed in the Result Summary For details see chapter 5 4 4 CCDF on page 150 CARA AAA AAA User Manual 1173 9357 02 11 50 R amp S9FSW K91 Measurem
93. on 80 0 MHz Standard ALE dew GI Meas Sahin 3 Ty y 3 Demodulation MIMO PPDUs to Analyze PPDU Analysis Mode for each property to analyze PPDU Format to measure Channel Bandwidth to measure up to CBW40 MHz i MCS Index STBC Field Auto same type as first PPDU Extension Spatial Streams sounding Auto same type as first PPDU mes Modulation Data Rate Mb s Index Stream 1 Stream 2 Stream 3 Stream 4 800ns GI 400ns GI Guard Interval Length Auto same type as first PPDU T Fig 5 5 Demodulation settings for IEEE 802 11n standard PPDU Analysis MOULE ene er ute dt ei hee etu ete ip t voee ri doces 134 PPDU Format tO Measures P RE REX RRR AREE ERA 134 Channel Bandwidth to measure GBW 2er ie a he tree nnn 135 MES INGE to USE LE 135 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance pear e pianist tee 136 NN 136 Extension Spatial Streams EE e EE 136 Table are EE 137 Guard Werte tal Lo DEE 137 PPDU Analysis Mode Defines whether all or only specific PPDUs are to be analyzed Auto same type as first PPDU The signal symbol field i e the PLCP header field of the first recog nized PPDU is analyzed to determine the details of the PPDU All PPDUS identical to the first recognized PPDU are analyzed All subsequent settings are set to Auto mode Auto individually for each PPDU All PPDUs are analyzed User defined User defined setti
94. operation DN8 DN16 parameters in previous R amp S Signal and Spectrum Ana lyzers DL All PPDUs are demodulated assuming long guard interval length corresponds to Demod all as long in manual operation DL16 DL32 parameters in previous R amp S Signal and Spectrum Ana lyzers RST ALL Example CONF WLAN GTIM AUTO TYPE DL Manual operation See Guard Interval Length on page 131 CONFigure WLAN GTIMe SELect lt GuardTime gt This remote control command specifies the guard time the PPDUs in the IEEE 802 11n or ac input signal should have If the guard time is specified to be detected from the input signal using the CONFigure WLAN GTIMe AUTO command then this command is query only and allows the detected guard time to be obtained Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt GuardTime gt SHORt NORMal SHORt Only the PPDUs with short guard interval are analyzed NORMal Only the PPDUs with long guard interval are analyzed Long in manual operation RST NORMal Example CONF WLAN GTIM SEL SHOR Manual operation See Guard Interval Length on page 131 CONFigure WLAN SMAPping MODE lt Mode gt This remote control command specifies the special mapping mode Parameters lt Mode gt DIRect SEXPansion USER DIRect direct SEXPansion expansion USER user defined Manual operation See Spatial Mapping Mode on page 138 CONFigure WLAN SMAPping NORMalis
95. page 85 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 The Overview and dialog boxes are updated to indicate the settings for the selected window WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 3 Signal Description The signal description provides information on the expected input signal Signal Input Source Frequency Amplitude Output Signal Characteristic Sel IEEE 802 11a II E ENT CIA Prior IEEE 802 11 2012 Standard RNIN EE 91 o A Eeer E EE EE EE O E EN TOlerance LiM EE 91 Standard Defines the WLAN standard depending on which WLAN options are installed The measurements are performed according to the specified standard with the correct limit values and limit lines Many other WLAN measurement settings depend on the selected standard see chap ter 4 6 Demodulation Parameters Logical Filters on page 77 Remote command CONFigure STANdard on page 184 Frequency Specifies the center frequency of the signal to be measured Remote command SENSe FREQuency CENTer on page 196 Tolerance Limit Defines the tolerance limit to be used for the measurement The r
96. raa Rn eeu 214 CONFioure WAN ANTMatrtv ANTenna Analyzerz trennen enne rennen nre entes 214 CONFigure WLAN AN TMatrix STATesstate ucro netter nao eii ko khu e Ee p ERE a iria 214 GONFigure WEAN DUNT COnTG EE CONFigure WLAN EXTension AUTO TYPE GONFig re WEAN GTIMe AU T sie enne cien bi Peerage eec E pd cott roce Ub dern Fete Pe A GONFigure WEAN GTIM amp AUTO TYBE n erat ren cr etn rrt thx et ai GONFigure WLEAN GT IMG SEL CL cire e tet e te n ER Ee D ERE UE nares GONFig re WEAN MIMO GAEP TUEG c eroe etc ia GONFigure WEAN MIMO CAPTute BUIFFer 3 nacio epi tinere nr tn exea cinere tn n ceo id 215 CONFigure WLAN MIMO CAPTure TYPE tnter rrr rt nne rrr d ean 215 GONFig re WEAN MIMO OSP ADDHRSSS ceteri tetti rema ta er dE Ced beri Fre ron ci n 216 GONFigure WEAN MIMO OSP MObBDuUle 2 2 ctn oneri t nitet rte ei e ec de proa 216 GONFigure WLAN PAYLoad LENGth SRO rnnt tnr ene re perpe AAA 233 CONFigure WLAN PVERror MRANge co cai ti rotes tk En ne dE ok ee Den epe YET EX Ee ea e CHE XE CE e nz ERN E 234 CONFigure WLAN RSYNc JOINed CONFigure WLAN SMAPping MODE GONFigure WEAN SMAPDping NORMAalise teh ioa ttn re th ne bert kb n e EE Ov PE ek RE EEN gg 223 GONFigure WEAN SMAPping TXS CNS isis satiate e i ree cay cede e E e EM Eve tus 223 CONFigure WLAN SMAPping TX lt ch gt STReam lt StreaM gt eene eene 224 CONFEioure WAN SMAbpoing Tsch TlMeshift E 224 CONFigur WLAN STIBC AUTO TY d EE
97. stop sweep INITiate CONTinuous OFF ABORt 1 Configuring the result display Activate following result displays 1 Magnitude Capture default upper left 2 Result Summary Detailed below Mag Capt 3 Result Summary Global default lower right 4 EVM vs Carrier next to Mag Capt LAY REPL 2 RSD LAY ADD WIND 1 RIGH EVC Result 4 Programming Examples R amp S FSW K91 Ee Signal description Use measurement standard IEEE 802 11n CONF STAN 6 Center frequency is 13 25 GHz FREQ CENT 13 25GHZ 4 5252 Configuring Data Acquisition Each measurement captures data for 10 ms SWE TIME 10ms Set the input sample rate for the captured I Q data to 20MHz TRAC IQ SRAT 20MHZ Number of samples captured per measurement 0 01s 20e6 samples per second 200 000 samples Include effects from adjacent channels switch off filter BAND FILT OFF Synchronization Improve performance perform coarse burst search initially SENS DEM TXAR ON Minimize the intersymbol interference FFT start offset determined automatically SENS DEM FFT OFFS AUTO dees Tracking and channel estimation Improve EVM accuracy estimate channel from preamble and payload SENS DEM CEST ON Use pilot sequence as defined in standard SENS TRAC PIL STAN Disable all tracking and compensation functions SENS TR
98. streams between multiple transmit antennas and multiple receive antennas MIMO multiple in multiple out As opposed to other Rohde amp Schwarz signal and spectrum analyzers in the R amp S FSW WLAN application MIMO is not selected as a specific standard Rather when you select the IEEE 802 11ac or n standard MIMO is automatically available In the default configuration a single transmit antenna and a single receive antenna are assumed which corresponds to the common SISO setup R amp S FSW K91 Measurement Basics Basic technologies Some basic technologies used in MIMO systems are introduced briefly here For more detailed information see the Rohde amp Schwarz Application Note Introduction to MIMO 1MA142_0e available for download from the Rohde amp Schwarz website MIMO systems use transmit diversity or space division multiplexing or both With transmit diversity a bit stream is transmitted simultaneously via two antennas but with different coding in each case This improves the signal to noise ratio and the cell edge capacity For space division multiplexing multiple different data streams are sent simultane ously from the transmit antennas Each receive antenna captures the superposition of all transmit antennas In addition channel effects caused by reflections and scattering etc are added to the received signals The receiver determines the originally sent symbols by multiplying the received symbols wit
99. the optional Digital Baseband Interface R amp S FSW B17 is installed Parameters lt State gt ON OFF RST OFF Manual operation See Input Sample Rate on page 95 Configuring Input via the Analog Baseband Interface R amp S FSW B71 The following commands are required to control the Analog Baseband Interface R amp S FSW B71 in a remote environment They are only available if this option is instal led Useful commands for Analog Baseband data described elsewhere INP SEL AIQ see INPut SELect on page 187 e SENSe FREQuency CENTer on page 196 Commands for the Analog Baseband calibration signal are described in the R amp S FSW User Manual Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Remote commands exclusive to Analog Baseband data input and output IC irte Leg ETC KR RE 192 INPUE CRFULESSAS ALTO iii a isa 192 INPutiIQ F LLscale LEVel uoc oro eorr aida 192 INPUTICSTYPE Sonar A A A EEE 193 Lee Kleer iaa 193 CALIDO AQ DCO Rise DEE 194 SENSe PROBesch SETup CMOFfset 2 2 rice aia 194 TRACED APCO STATE EE 194 TRACE OSAP COMA kaaa 195 TRACENGIAR COM EE 195 TRAGEAG AP Com RESUIE EE 195 INPut IQ BALanced STATe lt State gt This command defines whether the input is provided as a differential signal via all 4 Analog Baseband connectors or as a plain UO signal via 2 simple ended lines
100. the peak power The unit of the return values depends on the scaling of the y axis logarithmic scaling returns the power in the current unit linear scaling returns the power in W For SEM measurements the return value is the peak power of the reference range in the specified sub block OBANdwidth OBWidth Occupied bandwidth Returns the occupied bandwidth in Hz Usage Query only Retrieving Results Manual operation See Channel Power ACLR on page 48 See Occupied Bandwidth on page 49 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 lt Position gt 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 Marker Table on page 52 See Marker Peak List on page 52 CALCulate STATistics RESult lt t gt lt ResultType gt This command queries the results of a CCDF or ADP measurement for a specific trace Parameters lt ResultType gt MEAN Average RMS power in dBm measured during the measure ment time PEAK Peak power in dBm measured during the measurement time CFACtor Determined crest factor ratio of peak power to average pow
101. to SEM measurements in the WLAN application ISENSG lt n gt POW CES EM icc ee rne ato xeu esie erneuten dada 245 SENSe POWer SEM CLASS EE 246 SENSe lt n gt POWer SEM lt Type gt This command sets the Spectrum Emission Mask SEM measurement type Parameters lt Type gt IEEE ETSI User User Settings and limits are configured via a user defined XML file Load the file using MMEMory LOAD SEM STATe on page 300 IEEE Settings and limits are as specified in the IEEE Std 802 11n 2009 Figure 20 17 Transmit spectral mask for 20 MHz transmission For other IEEE standards see the parameter values in the table below After a query IEEE is returned for all IEEE standards ETSI Settings and limits are as specified in the ETSI standard RST IEEE Table 10 6 Supported IEEE standards Manual operation The spectrum emission mask measurement Parameter value is performed according to the standard IEEE 802 11n 2009 IEEE Std 802 11n 2009 IEEE 20M 2 4G Figure 20 17 Transmit spectral mask for 20 or MHz transmission IEEE 2009 20 2 4 IEEE 802 11n 2009 IEEE Std 802 11n 2009 IEEE 2009 40 2 A 40M 2 4G Figure 20 18 Transmit spectral mask for a 40 MHz channel Configuring Frequency Sweep Measurements on WLAN Signals Manual operation The spectrum emission mask measurement is performed according to the standard Parameter value IEEE 802 11n 2009 20M 5G IE
102. to measure the number of DUT Tx Antennas as defined in DUT MIMO Configuration Data capturing is performed manually via the analyzer s user interface Remote command CONFigure WLAN MIMO CAPTure TYPE on page 215 Simultaneous Signal Capture Setup For each RX antenna from which data is to be captured simultaneously the settings are configured here Tip the LED symbol indicates the state of the Rx antenna Color State gray antenna off or IP address not available valid red antenna on and IP address valid but not accessible green antenna on and IP address accessible State Simultaneous Signal Capture Setup Switches the corresponding slave analyzer on or off In On state the slave analyzer captures data This data is transferred via LAN to the master for analysis of the MIMO system Remote command CONFigure WLAN ANTMatrix STATe lt state gt on page 214 Analyzer IP Address Simultaneous Signal Capture Setup Defines the IP addresses of the slaves connected via LAN to the master Remote command CONFigure WLAN ANTMatrix ADDRess add on page 214 Assignment Simultaneous Signal Capture Setup Assignment of the expected antenna to an analyzer For a wired connection the assignment of the Tx antenna connected to the analyzer is a possibility For a wired connection and Direct Spatial Mapping the Spectrum Flatness traces in the diagonal contain the useful information in case the signal transmitted fr
103. to the expected maximum signal level by setting the Reference Level to this maximum Compensate for any external attenuation or gain into consideration by defining a Reference Level offset Attenuation To optimize the signal to noise ratio of the measurement for high signal levels and to protect the R amp S FSW from hardware damage provide for a high attenuation Use AC coupling for DC input voltage User Manual 1173 9357 02 11 79 Triggered measurements Amplification To optimize the signal to noise ratio of the measurement for low signal levels the sig nal level in the R amp S FSW should be as high as possible but without introducing com pression clipping or overload Provide for early amplification by the preamplifier and a low attenuation Impedance When measuring in a 75 O system connect an external matching pad to the RF input and adapt the reference impedance for power results The insertion loss is compensa ted for numerically 4 9 Triggered measurements In a basic sweep measurement with default settings the sweep is started immediately when you start the measurement for example by pressing the RUN SINGLE key How ever sometimes you want the measurement to start only when a specific condition is fulfilled for example a signal level is exceeded or in certain time intervals For these cases you can define a trigger for the measurement In FFT sweep mode the trigger defines when the data acquisition starts
104. updated when the measurement is stopped However in this case the data is written to the same capture buffer for all antennas namely the one selected for RUNS SINGLE or RUN CONT gt updates in the MIMO Capture tab Thus the assignment of the individual data streams to antennas is no longer visible in the result displays User Manual 1173 9357 02 11 158 R amp S FSW K91 How to Perform Measurements in the WLAN Application To perform an automated sequential measurement with an OSP switch box This measurement setup requires an additional R amp S OSP switch box For details on setting up and using this instrument see the corresponding documentation 1 Press the MODE key on the front panel of the R amp S FSW 2 Select the WLAN item gt WLAN The R amp S FSW opens a new measurement channel for the WLAN application 3 Select the Overview softkey to display the Overview for a WLAN measurement 4 Select the Signal Description button to select the digital standard IEEE 802 11ac or IEEE 802 11n 5 Select the Input Frontend button and then the Frequency tab to define the input signal s center frequency The reference level is adapted automatically 6 Select the Signal Capture button to define how much and which data to capture from the input signal 7 Select the MIMO Capture tab to define how the data from the MIMO antennas is to be captured a For the DUT MIMO Config select the
105. vary depending on the selected digital standard see CONFigure STANdard on page 184 Manual configuration is described in chapter 5 3 8 Demodulation on page 124 GONFigure WLAN EXTension AUTO TYPE conocia riadas 220 CONFloure WAN GTlMe AUTO 221 CONFiqures WLAN GTIME AUTO TYPE conoci 221 CONFigure WLAN GTIMe SElLect esrin aaora de 222 GONFigure WLARESMAP ping MOD Bisa comia 223 CONFigure WLAN SMAPping NORMalise nono nono 223 CONFigure WLAN SMAPping Eege iii EES Seed 223 CONFigure WLAN SMAPping TX ch STReamsstream nana 224 CONFigure WLAN SMAPping T X lt ch gt TIMeShift cececeeeeeeeeeeeeeeeeeeeaeeeeaeaaaeaaeneneteneees 224 CONPIqure WEAN STBE AUTO Ak EE 224 SENSe BANDWidthGHANneAUTO TYPE cocinar 225 SENSe IDEMod FORMaEBANaGlyze ocio nit ias 227 ISENGe IDEMod FORMat BANzahvzeBivbe AUTOTbE enne 228 ISENSeIDEMod FORMatt BCONtengt AUTO 230 SENSe DEMod FORMACMCS INGO E 230 SENSe DEMod FORMat MCSindex MODE c ccceeeeeceeeeeeeeeeaeeeeeeecaeesaeeeaaeseaeeeaeeees 230 SENSeTDEMod FORMAGNS ESINGOX ER 231 SENSe DEMod FORMaENSTSindex MODE cancion ii and 231 SENSe n DEMod FORMatSIGSymlbol nen tine eon tnr nita i Le ona n nean ennt 232 CONFigure WLAN EXTension AUTO TYPE lt PPDUType gt Defines the PPDUs taking part in the analysis according to the Ness Extension Spatial Streams field content for IEEE 802
106. want to add See the table below for available parameter values When adding a new window the command returns its name by default the same as its number as a result LAY ADD 1 LEFT MTAB Result 2 Adds a new window named 2 with a marker table to the left of window 1 Query only See AM AM on page 23 See AM PM on page 23 See AM EVM on page 24 See Bitstream on page 25 See Constellation on page 27 See Constellation vs Carrier on page 28 See EVM vs Carrier on page 29 See EVM vs Chip on page 30 See EVM vs Symbol on page 30 See FFT Spectrum on page 31 See Freq Error vs Preamble on page 32 See Group Delay on page 33 See Magnitude Capture on page 34 See Phase Error vs Preamble on page 35 See PLCP Header IEEE 802 11b g GSSS on page 36 See PvT Full PPDU on page 37 See PvT Rising Edge on page 38 See PvT Falling Edge on page 39 See Result Summary Detailed on page 40 See Result Summary Global on page 41 See Signal Field on page 43 See Spectrum Flatness on page 46 See Diagram on page 51 See Result Summary on page 52 See Marker Table on page 52 See Marker Peak List on page 52 Table 10 7 lt WindowType gt parameter values for WLAN application Parameter value Window type Window types for I Q data AMAM AM AM IEEE 802 11a g OFDM ac n p only R amp S FSW K91 Remote Commands for WLAN Measurements
107. 00 Programming Examples R amp S FSW KO91 ieo reti tee etti 302 10 1 Common Suffixes For the description of the remote commands in the WLAN application the following common suffixes are used Table 10 1 Common suffixes for WLAN measurements on l Q data Suffix Value range Description n 1 16 Window lt k gt 1 8 Limit 10 2 10 2 1 Introduction Suffix Value range Description lt t gt 1 Trace lt m gt 1 4 Marker Table 10 2 Common suffixes for frequency sweep measurements Suffix Value range Description lt n gt 1 16 Window lt t gt 1 6 Trace lt m gt 1 16 Marker lt ch gt 1 18 Tx channel Channel 1 11 ALTernate or ADJa cent channel lt k gt 1 8 Limit line 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 or events 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 after the last header element even if the command contains a parameter A header contains one or more keywords separated by a colon
108. 00000000E 006 0 000000000 000000000E 006 FO 000000000 0 000000000 0 000000000 2 108782336E4 000000000 4 109000064E 4 000000000 4 009 FO 00000000 009 r0 00000000 13987200E4 Ra Start freq Stop freq RBW Hz Freq peak Abs peak Rel peak Delta to Limit ng Hz Hz power Hz power power margin check e dBm dB result No 1 1 0000000 1 2750000 8 5000000 1 0000000 2 1087823 8 0571777 7 8827995 2 98279 0 0 0 00 00E 007 00E 006 00E 006 36E 009 34E 001 30E 001 9530E 00 00 00 001 00 00 00 00 00 00 00 00 00 0 0 0 2 2 0000000 8 5000000 7 5000000 1 0000000 2 1090000 8 1585472 7 9841690 3 08416 0 0 0 00 00E 006 00E 006 00E 006 64E 009 11E 001 06E 001 9006E 00 00 00 001 00 00 00 00 00 00 00 00 00 0 0 0 3 3 0000000 7 5000000 3 5000000 1 0000000 2 1139872 4 2027084 4 0283302 5 27056 0 0 0 00 00E 006 00E 006 00E 006 00E 009 35E 001 31E 001 5033 00 00 00 00 00 00 00 00 00 00 00 00 0 0 0 009 R amp S FSW K91 Annex Reference A Annex Reference A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input Definitions e Input sample rate ISR the sample rate of the useful data provided by the con nected instrument to the R amp S FSW input e User Output Sam
109. 1 ac standard Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Mode gt Example Manual operation FBURst ALL MEASure DEMod FBURst The Nsts of the first PPDU is detected and subsequent PPDUs are analyzed only if they have the same Nsts corresponds to Auto same type as first PPDU ALL All recognized PPDUs are analyzed according to their individual Nsts corresponds to Auto individually for each PPDU MEASure Only PPDUs with the Nsts specified by SENSe DEMod FORMat NSTSindex are analyzed DEMod The Nsts index specified by SENSe DEMod FORMat NSTSindexis used for all PPDUs RST FBURst SENS DEM FORM NSTS MODE MEAS SENS DEM FORM NSTS 1 See Nsts to use on page 129 SENSe lt n gt DEMod FORMat SIGSymbol State Activates and deactivates signal symbol field decoding For IEEE 802 11b this command can only be queried as the decoding of the signal field is always performed for this standard Parameters for setting and query lt State gt Manual operation OFF Deactivates signal symbol field decoding All PPDUs are assumed to have the specified PPDU format PSDU modula tion regardless of the actual format or modulation ON If activated the signal symbol field of the PPDU is analyzed to determine the details of the PPDU Only PPDUs which match the PPDU type PSDU modulation defined by SEN
110. 101 SENSe FREQuency CENTer STEP AUTO lt State gt This command couples or decouples the center frequency step size to the span Parameters lt State gt ON OFF 0 1 RST 1 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Example FREQ CENT STEP AUTO ON Activates the coupling of the step size to the span SENSe FREQuency OFFSet lt Offset gt This command defines a frequency offset If this value is not O 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 102 Note In MSRA mode the setting command is only available for the MSRA Master For MSRA applications only the query command is available Parameters lt Offset gt Range 100 GHz to 100 GHz RST 0 Hz Example FREQ OFFS 1GHZ Usage SCPI confirmed Manual operation See Frequency Offset on page 102 10 5 3 2 Amplitude Settings The following commands are required to configure the amplitude settings in a remote environment Useful commands for amplitude settings described elsewhere e INPut COUPling on page 186 e INPut IMPedance on page 187 e SENSe ADJust LEVel on page 244 Remote commands exclusive to amplitude settings CAL Cullate sn UNIT POW f 199 CONFigure POWERAUTO coo
111. 11 Trigger Unit and the required con nections see the R amp S FS Z11 Trigger Unit Manual Multiple Measurement Channels and Sequencer Function 9 Configuration 5 1 The default WLAN I Q measurement captures the I Q data from the WLAN signal and determines various characteristic signal parameters such as the modulation accuracy spectrum flatness center frequency tolerance and symbol clock tolerance in just one measurement see chapter 3 1 WLAN UO Measurement Modulation Accuracy Flat ness and Tolerance on page 13 Other parameters specified in the WLAN 802 11 standard must be determined in sepa rate measurements see chapter 5 4 Frequency Sweep Measurements on page 147 In settings required to configure each of these measurements are described here Selecting the measurement type P To select a different measurement type do one of the following e Select the Overview softkey In the Overview select the Select Measure ment button Select the required measurement e Press the MEAS key on the front panel In the Select Measurement dialog box select the required measurement e Multiple Measurement Channels and Sequencer Funchon 85 Display Cobfiguralloh ect rr cert ti EE a 87 e WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 87 e Frequency Sweep Measurements eene 147 Multiple Measurement Channels and Sequencer Function When you activate an application a new
112. 1173 9357 02 11 53 4 4 1 4 1 1 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM Measurement Basics Some background knowledge on basic terms and principles used in WLAN measure ments is provided here for a better understanding of the required configuration set tings Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM This description gives a rough view of the signal processing when using the R amp S FSW WLAN application with the IEEE 802 11a or g OFDM standard Details are disregar ded in order to provide a concept overview Abbreviations alk symbol at symbol of subcarrier k EVM error vector magnitude of subcarrier k EVM error vector magnitude of current packet g signal gain Af frequency deviation between Tx and Rx symbol index 1 nof_Symbols nof_symbols number of symbols of payload Hk channel transfer function of subcarrier k k channel index k 31 32 Kmod modulation dependent normalization factor amp relative clock error of reference oscillator fik subcarrier of symbol e Block Diagram for Multicarrier Measurements sese 54 e Literature on the IEEE 802 11a Standard seeeeeeee 61 Block Diagram for Multicarrier Measurements A diagram of the significant blocks when using the IEEE 802 11a or g OFDM stand ard in the R amp S FSW WLAN applica
113. 11n standard only Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt PPDUType gt FBURst ALL MO M1 M2 M3 DO D1 D2 D3 The first PPDU is analyzed and subsequent PPDUs are ana lyzed only if they match FBURst The Ness field contents of the first PPDU is detected and subse quent PPDUs are analyzed only if they have the same Ness field contents corresponds to Auto same type as first PPDU ALL All recognized PPDUs are analyzed according to their individual Ness field contents corresponds to Auto individually for each PPDU MO M1 M2 M3 Only PPDUs with the specified Ness value are analyzed DO D1 D2 D3 All PPDUs are analyzed assuming the specified Ness value RST FBURst Example CONF WLAN EXT AUTO TYPE MO Manual operation See Extension Spatial Streams sounding on page 136 CONFigure WLAN GTIMe AUTO lt State gt This remote control command specifies whether the guard time of the input signal is automatically detected or specified manually IEEE 802 11n or ac only Parameters lt State gt ON The guard time is detected automatically according to CONFigure WLAN GTIMe AUTO TYPE on page 221 OFF The guard time is defined by the CONFigure WLAN GTIMe SELect command RST ON Manual operation See Guard Interval Length on page 131 CONFigure WLAN GTIMe AUTO TYPE lt Type gt This remote control command specifies which PPDUs
114. 1ac D1 1 August 2011 Figure 22 19 Transmit spectral mask for a 80 MHz channel lEEE AC D1 1 An 5 IEEE AC D1 1 80 5 SENSe POWer SEM CLASs Index This command sets the Spectrum Emission Mask SEM power class index The index represents the power classes to be applied The index is directly related to the entries displayed in the power class drop down combo box within the SEM settings configura tion page Parameters Index RST 0 10 7 10 7 1 Configuring the Result Display Configuring the Result Display The following commands are required to configure the screen display in a remote envi ronment The corresponding tasks for manual operation are described in chapter 5 2 Display Configuration on page 87 The suffix lt n gt in the following remote commands represents the window 1 16 in the currently selected measurement channel e General Window elt Le EE 247 e Working with Windows in the Display 248 e Selecting Items to Display in Result Gummam eee 254 e Configuring the Spectrum Flatness and Group Delay Result Displays 256 e Configuring the AM AM Result Display 256 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 176 DISPlav e E EE 247
115. 2 11 can not only be measured by the WLAN application itself it can also be imported to the application provided it has the correct format Furthermore the analyzed UO data from the WLAN application can be exported for further analysis in external applications See chapter 7 1 Import Export Functions on page 152 Parameters lt Source gt RF Radio Frequency RF INPUT connector RST RF Manual operation See Radio Frequency State on page 93 See Digital UO Input State on page 95 See Analog Baseband Input State on page 97 Configuring Digital UO Input and Output Useful commands for digital UO data described elsewhere e INP SEL DIQ see INPut SELect on page 187 e TRIGger SEQuence LEVel BBPower on page 206 Remote commands for the R amp S DiglConf software Remote commands for the R amp S DiglConf software always begin with SOURce EBOX Such commands are passed on from the R amp S FSW to the R amp S DiglConf automatically which then configures the R amp S EX IQ BOX via the USB connection All remote commands available for configuration via the R amp S DiglConf software are described in the R amp SGEX IQ BOX Digital Interface Module R amp SGDiglConf Software Operating Manual Example 1 SOURCe EBOX RST SOURce EBOX IDN Result Rohde8Schwarz DiglConf 02 05 436 Build 47 Example 2 SOURCe EBOX USER CLOCk REFerence FREQuency 5MHZ Defines the freque
116. 2 11b g DSSS are considered for measurement analysis If disabled a maximum and minimum Min Max Payload Length IEEE 802 11b g DSSS can be defined and all PPDUs whose length is within this range are consid ered Remote command IEEE 802 11a g OFDM SENSe DEMod FORMat BANalyze SYMBols EQUal on page 237 IEEE 802 11 b g DSSS SENSe DEMod FORMat BANalyze DURation EQUal on page 236 SENSe DEMod FORMat BANalyze DBYTes EQUal on page 235 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Min Max No of Data Symbols IEEE 802 11a g OFDM ac n p If the Equal PPDU Length setting is enabled the number of data symbols defines the exact length a PPDU must have to be considered for analysis If the Equal PPDU Length setting is disabled you can define the minimum and maxi mum number of data symbols a PPDU must contain to be considered in measurement analysis Remote command SENSe DEMod FORMat BANalyze SYMBols MIN on page 238 SENSe DEMod FORMat BANalyze SYMBols MAX on page 238 Min Max Payload Length IEEE 802 11b g DSSS If the Equal PPDU Length setting is enabled the payload length defines the exact length a PPDU must have to be considered for analysis If the Equal PPDU Length setting is disabled you can define the minimum and maxi mum payload length a PPDU must contain to be considered in measurement analysis
117. 802 11b or g DSSS According to standard The pilot sequence is determined according to the corresponding WLAN standard In case the pilot generation algorithm of the device under test DUT has a problem the non standard conform pilot sequence might affect the measurement results or the WLAN appli cation might not synchronize at all onto the signal generated by the DUT WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Detected The pilot sequence detected in the WLAN signal to be analyzed is used by the WLAN application In case the pilot generation algorithm of the device under test DUT has a problem the non standard con form pilot sequence will not affect the measurement results In case the pilot sequence generated by the DUT is correct it is recommen ded that you use the According to Standard setting because it gen erates more accurate measurement results Remote command SENSe TRACking PILots on page 219 5 3 8 Demodulation The demodulation settings define which PPDUs are to be analyzed thus they define a logical filter The available demodulation settings vary depending on the selected digital standard in the Signal Description see Standard on page 91 e Demodulation IEEE 802 11a 9 OFDM Dc iei e teet te 124 e Demodulation IEEE 802 1186 nete tte ecd 127 e Demodulation IEEE 802 11b g DG EE 131 e Demodulation EE CH kees erede erret gren nete c 133 e Demodulation MIM
118. A 103 L Reference Level Mode prai i eii 103 L Reference Level 104 ona Lal RMS MEET EM 104 L Shifting the Display O feet ee tete tenete rtntn tens 104 e A 104 L Setting the Reference Level Automatically Auto Level 105 FRE suiRUII B 105 L Attenuation Mode Value nono rn conan 105 Using Electronic Attenuation Option B25 2 c iret iced 105 PTV WE SS ie ce E 106 L Preamplifier option B34 tette tnnt ttrtntr testas 106 Reference Level Settings The reference level defines the expected maximum signal level Signal levels above this value may not be measured correctly which is indicated by the IF OVLD status display Reference Level Mode Reference Level Settings By default the reference level is automatically adapted to its optimal value for the cur rent input data continuously At the same time the internal attenuators and the pre amplifier are adjusted so the signal to noise ratio is optimized while signal compres sion clipping and overload conditions are minimized WLAN IQ Measurement Modulation Accuracy Flatness Tolerance In order to define the reference level manually switch to Manual mode In this case you must define the following reference level parameters Remote command CONF POW AUTO ON see CONFigure POWer AUTO on page 241 Reference Level Reference Level Settings Defines the expected maximum signal level Signal levels above this value may not be measured correctly
119. AC LEV OFF SENS TRAC PHAS OFF SENS TRAC TIME OFF Zieser Demodulation Define a user defined logical filter to analyze SENS DEM FORM BCON AUTO OFF all PPDU formats SENS DEM FORM BAN BTYP AUTO TYPE ALL 20MHZ channel bandwidth SENS BAND CHAN AUTO TYPE MB20 an MCS Index 1 SENS DEM FORM MCS MODE MEAS SENS DEM FORM MCS 1 STBC field 1 CONF WLAN STBC AUTO TYPE M1 Ness 1 CONF WLAN EXT AUTO TYPE M1 short guard interval length 8 samples CONF WLAN GTIM AUTO ON CONF WLAN GTIM AUTO TYPE MS Programming Examples R amp S FSW K91 f a 8 Evaluation range settings Calculate statistics over 10 PPDUs SENS BURS COUN STAT ON SENS BURS COUN 10 Determine payload length from HT signal CONF WLAN PAYL LENG SRC HTS Payload length 8 16 symbols SENS DEM FORM BAN SYMB EQU OFF SENS DEM FORM BAN SYMB MIN 8 SENS DEM FORM BAN SYMB MAX 16 7 Measurement settings Define units for EVM and Gain imbalance results UNIT EVM PCT UNIT GIMB PCT a Defining Limits Define non standard limits for demonstration purposes and return to standard limits later Query current limit settings CALC LIM BURS ALL Set new limits Average CF error 5HZ max CF error 10HZ average symbol clock error 5 max symbol clock error 10 average I Q offset 5 maximum I Q offset 10 average
120. AUTO on page 190 Adjust Reference Level to Full Scale Level If enabled the reference level is adjusted to the full scale level automatically if any change occurs Remote command INPut DIQ RANGe COUPling on page 190 Connected Instrument Displays the status of the Digital Baseband Interface connection If an instrument is connected the following information is displayed e Name and serial number of the instrument connected to the Digital Baseband Inter face Used port e Sample rate of the data currently being transferred via the Digital Baseband Inter face e Level and unit that corresponds to an I Q sample with the magnitude 1 Full Scale Level if provided by connected instrument Remote command INPut DIQ CDEVice on page 189 DiglConf Starts the optional R amp S DiglConf application This softkey is available in the In Output menu but only if the optional software is installed Note that R amp S DiglConf requires a USB connection not LAN from the R amp S FSW to the R amp S EX IQ BOX in addition to the Digital Baseband Interface R amp S FSW B17 connection R amp S DiglConf version 2 20 360 86 Build 170 or higher is required To return to the R amp S FSW application press any key on the front panel The R amp S FSW application is displayed with the Input Output menu regardless of which key was pressed For details on the R amp S DiglConf application see the R amp SGEX IQ BOX Digital Inter face Module R am
121. BANalyze DBYTes EQUal State For IEEE 802 11b and g DSSS signals only If enabled only PPDUs with a specific payload length are considered for measure ment analysis If disabled only PPDUs whose length is within a specified range are considered The payload length is specified by the SENSe DEMod FORMat BANalyze DBYTes MIN command A payload length range is defined as a minimum and maximum number of symbols the payload may contain see SENSe DEMod FORMat BANalyze DBYTes MAX on page 235 and SENSe DEMod FORMat BANalyze DBYTes MIN Parameters State ON OFF RST OFF Manual operation See Equal PPDU Length on page 140 SENSe DEMod FORMat BANalyze DBYTes MAX lt NumDataBytes gt If the SENSe DEMod FORMat BANalyze DBYTes EQUal command is set to false this command specifies the maximum number of data bytes allowed for a PPDU to take part in measurement analysis If the SENSe DEMod FORMat BANalyze DBYTes EQUal command is set to true then this command has no effect Parameters lt NumDataBytes gt RST 64 Default unit bytes Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Manual operation See Min Max Payload Length IEEE 802 11b g DSSS on page 141 SENSe DEMod FORMat BANalyze DBYTes MIN lt NumDataBytes gt For IEEE 802 11b and g DSSS signals only If the SENSe DEMod FORMat BANalyze DBYTe
122. BSTestState gt State of the PRBS test Not Started Has to be Started Started Passed Failed Done lt SampleRateType gt 0 Maximum sample rate is displayed 1 Current sample rate is displayed lt FullScaleLevel gt The level in dBm that should correspond to an I Q sample with the magnitude 1 if transferred from connected device If not available 9 97637 is returned Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Example INP DIQ CDEV Result 1 SMU200A 103634 Out A 70000000 100000000 Passed Not Started 0 0 Manual operation See Connected Instrument on page 96 INPut DIQ RANGe UPPer AUTO lt State gt If enabled the digital input full scale level is automatically set to the value provided by the connected device if available This command is only available if the optional Digital Baseband interface option R amp S FSW B17 is installed Parameters lt State gt ON OFF RST OFF Manual operation See Full Scale Level on page 95 INPut DIQ RANGe COUPling State If enabled the reference level for digital input is adjusted to the full scale level automat ically if the full scale level changes This command is only available if the optional Digital Baseband Interface R amp S FSW B17 is installed Parameters lt State gt ON OFF RST OFF Manual operation See Adjust Reference Level to Full Scale Level on page 96 INPut DIQ RANGe UPPer lt Lev
123. BURSt EVM ESYMbol IMMediate command is also supported for the IEEE 802 11b and g DSSS standards However for new remote control programs use the LAYout commands see chapter 10 7 2 Working with Windows in the Dis play on page 248 Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Manual operation See EVM vs Chip on page 30 CONFigure BURSt EVM ESYMbol IMMediate This remote control command configures the measurement type to be EVM vs Symbol Selecting a Measurement For IEEE 802 11b and g DSSS standards this command selects the EVM vs Chip result display Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See EVM vs Chip on page 30 See EVM vs Symbol on page 30 CONFigure BURSt PREamble IMMediate This remote control command configures the measurement type to be Frequency Error vs Preamble or Phase Error vs Preamble Which of the two is determined by CONFigure BURSt PREamble SELect Manual operation See Freq Error vs Preamble on page 32 See Phase Error vs Preamble on page 35 CONFigure BURSt PREamble SELect lt ErrType gt This remote control command specifies whether frequency or phase results are dis played when the measurement type is set to Error Vs Preamble CONFigure BURSt PREamble IMMediate on page 180 Parameters lt ErrType
124. CII values separated by in the following order lt average CF error gt lt max CF error gt lt average symbol clock error gt max symbol clock error average UO offset lt maxi mum UO offset average EVM all carriers max EVM all car riers gt lt average EVM data carriers gt lt max EVM data carriers gt lt average EVM pilots gt lt max EVM pilots gt CALCulate LIMit BURSt EVM ALL AVERage lt Limit gt CALCulate LIMit BURSt EVM ALL MAXimum Limit This command sets or queries the average or maximum error vector magnitude limit for all carriers as determined by the default WLAN measurement Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance For details on the EVM results and the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Parameters lt Limit gt numeric value in dB The unit for the EVM parameters can be changed in advance using UNIT EVM on page 268 Default unit DB CALCulate LIMit BURSt EVM DATA AVERage Limit CALCulate LIMit BURSt EVM DATA MAXimum Limit This command sets or queries the average or maximum error vector magnitude limit for the data carrier determined by the default WLAN measurement For details on the EVM results and the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Parameters Limit num
125. CONDition lt ChannelName gt STATus QUEStionable LIMit lt n gt 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 Status Registers 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 10 11 3 4 Controlling the ENABle Part STATus OPERation ENABle lt SumBit gt STATus QUEStionable ENABle lt SumBit gt STATus QUEStionable ACPLimit ENABle lt SumBit gt lt ChannelName gt STATus QUEStionable LIMit lt n gt ENABle lt SumBit gt lt ChannelName 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 10 11 3 5 Controlling the Negative Transition Part STATus
126. CP header of the PPDU This result display is only available for single carrier measurements IEEE 802 11b g DSSS for other standards use Signal Field instead 1 PLCP Header Signal PSDU Length Fig 3 17 PLCP Header result display for IEEE 802 11b g DSSS standards The following information is provided The signal field information is provided as a decoded bit sequence and where appro priate also in human readable form beneath the bit sequence for each PPDU Table 3 4 Demodulation results in PLCP Header result display IEEE 802 11b g DSSS Result Description Example PPDU Number of the decoded PPDU PPDU 1 A colored block indicates that the PPDU was successfully deco ded Signal Information in signal field 01101110 The decoded data rate is shown below 11 MBits s EES User Manual 1173 9357 02 11 36 R amp S FSW K91 Measurements and Result Displays EH Result Description Example Service Information in service field 00100000 Symbol clock state Modulation format Length extension Lock CCK bit state where Symbol clock state Locked Modulation format see table 4 1 Length extension bit state 1 set not set PSDU Length Information in length field 0000000001 11100 Time required to transmit the PSDU 0 120 us CRC Information in CRC field 111010011100111 Result of cyclic redundancy code check OK or Failed 0 OK
127. Ce Y SCALe RLEVel OFFSet on page 199 Unit Reference Level Settings The R amp S FSW measures the signal voltage at the RF input In the default state the level is displayed at a power of 1 mW dBm Via the known input impedance 50 Q or 75 Q see Impedance on page 93 conversion to other units is possible The fol lowing units are available and directly convertible e dBm dBmV dByV dBpA dBpW Volt Ampere WLAN IQ Measurement Modulation Accuracy Flatness Tolerance e Watt Remote command INPut IMPedance on page 187 CALCulate lt n gt UNIT POWer on page 199 Setting the Reference Level Automatically Auto Level Reference Level Set tings Automatically determines the optimal reference level for the current input data At the same time the internal attenuators and the preamplifier are adjusted so the signal to noise ratio is optimized while signal compression clipping and overload conditions are minimized In order to do so a level measurement is performed to determine the optimal reference level You can change the measurement time for the level measurement if necessary see Changing the Automatic Measurement Time Meastime Manual on page 145 Remote command CONFigure POWer AUTO on page 199 RF Attenuation Defines the attenuation applied to the RF input This function is not available for input from the Digital Baseband Interface R amp S FSW B17 Attenuation Mode Value RF Att
128. E 193 INPUNE SELEG E 187 INSTrument GREate DUPLicate coito aiii 173 ENT lee E E TEE 174 INSTrument CREate NE Wisin A EE XE EE FERRI 173 INSTr ment RIES 174 INS TrUment EIS EE 174 INS Tr metnt ENAITIQ E 176 le Kater E E Gi ritiro n te a in ie a onte er Pho lin ccr Eds poit EX x UH Ea RR M REDIERE 176 LAYOUEADDEWINDOW errore ree er epe rese repa cere Ye y vy Ee eeu FH EF e EXAM PNE USER 248 EAYout CATalogEWINDBOWJ oio ei rer Fs Adi e APER PUE EVER CREME DISTR 250 LEAYout IDENtIyWINDOW cette ira eat aa Fere orb ere kn reve SEELEN ala ee XY EAE 251 LAY out REMove Te EE LAYout REPLace WINDow E BN dee LE LAYU WINDOWS ADD costaria dE t a cede apa EAEE EAEE ESSENSE 253 LAYU WINDOWS IDENY occiso 254 LAY out WINDow lt n gt REMOVE copita a EE EE a ESE 254 ido nim ATTI DT op eiui dE c r aa ad 254 MMEMOrysEOAD IQ RRE 288 MMEMory LOAD SEM STATe 300 MMEMory STORS IQ S TAT6 riot err ttr etti eee er e tp ten ER Re RR ELE Ce Y NR ERR 289 DIER We 196 OUTPut TRIGgersport DIRGCIOI 5 orn rre a ia 212 QUTPUt TRIGgersport Eel ntt ttti t terre rtp der eo ere E 212 OUTP t TEIGgersport OT d utro p trn e remate aae ru Do tees tr tr tx tpe a Dese oce enti tenes 212 OUTPutTRIGg er lt port gt PULSe IMMediate retten eene ri eene nnns 213 OUTPuETRIGger lt port gt PULSE LEN GI conterere rre ene rei trn ett dte ENEE 213 STATus OPERation CONDI ORDI iso titt reete Deco Pri
129. EE Std 802 11n 2009 Figure 20 17 Transmit spectral mask for 20 MHz transmission EEE_2009_20_5 IEEE 802 11n 2009 40M 5G IEEE Std 802 11n 2009 Figure 20 18 Transmit spectral mask for a 40 MHz channel IEEE 2009 40 5 IEEE 802 11mb D08 20M 2 4G IEEE Std 802 11n 2009 Figure 20 17 Transmit spectral mask for 20 MHz transmission IEEE Draft P802 11 REVmb D8 0 March 2011 Figure 19 17 Transmit spectral mask for 20 MHz transmission in the 2 4 GHz band EEE D08 20 2 4 IEEE 802 11mb D08 40M 2 4G IEEE Std 802 11n 2009 Figure 20 18 Transmit spectral mask for a 40 MHz channel IEEE Draft P802 11 REVmb D8 0 March 2011 Figure 19 18 Transmit spectral mask for a 40 MHz channel in the 2 4 GHz band EEE D08 40 2 4 Figure 19 20 Transmit spectral mask for a 40 MHz channel in the 5 GHz band IEEE 802 11mb D08 20M 5G IEEE Draft P802 11 REVmb D8 0 March 2011 IEEE DO8 20 5 Figure 19 19 Transmit spectral mask for 20 MHz transmission in the 5 GHz band IEEE 802 11mb D08 40M 5G IEEE Draft P802 11 REVmb D8 0 March 2011 IEEE DO8 40 5 IEEE 802 11ac D1 1 20M 5G IEEE P802 11ac D1 1 August 2011 Figure 22 17 Transmit spectral mask for a 20 MHz channel IEEE AC D1 1 20 5 IEEE 802 11ac D1 1 40M 95G IEEE 802 11ac D1 1 80M 5G IEEE P802 11ac D1 1 August 2011 Figure 22 18 Transmit spectral mask for a 40 MHz channel IEEE P802 1
130. EO S cocina eege R R amp S DIGI COME EE 96 R amp S EX IQ BOX elle eer SE 96 Record length A teteearac Se E 307 Relationship to sample rate sssss 308 Reference level UA E Auto level continuous CTU FCR E RP TRES SICH OIffSeL seien Offset softkey Hot VT Remote commands BASICS Oe MAX ccoo ntc eee 168 Bool amp ri Values morosidad eren expe ps 172 GapitaliZatiOli ecco reperti aeuo epi aves tace interes 169 Character EE 172 Data DIOCKS cocaina orante 172 tut Ze 171 ioc ERE 300 Optional KeyWOEdS etaient evt torte te nexis 170 LTE UE 170 Strings EE 169 FepetitionifilerVal recep rra reato rh erar toti 113 d c 113 Resetting RF input DrOlG CLIOD coena toe rie eege gegeteig 78 186 Restoring Ghantiel Settilgs EE 90 Result configuration DONKEY e P 142 Result displays E AM EVM AM PM Bitstream 1o Configuration remote sss 247 CONOUG WEE 87 Constellation 27 Constellation vs carrier 28 Diagram 51 Evaluated data EVM vs carrier 29 Re TE 30 EVIVIVS SYMDO EE 30 FFT spectrum Freq Error vs Preamble sssssssesssss 32 Group Delay iii ri 33 Magnitude Capture 34 Marker table 252 Peak list 4 52 Phase Error vs Preamble mee 35 PVT Falling Edge rn 39 PVT PU
131. EQuence LEVel BBPower on page 206 TRIGger SEQuence LEVel RFPower on page 208 Repetition Interval Trigger Source Settings Defines the repetition interval for a time trigger The shortest interval is 2 ms The repetition interval should be set to the exact pulse period burst length frame length or other repetitive signal characteristic Remote command TRIGger SEQuence TIME RINTerval on page 211 Drop Out Time Trigger Source Settings Defines the time the input signal must stay below the trigger level before triggering again For more information on the drop out time see chapter 4 9 3 Trigger Drop Out Time on page 81 Remote command TRIGger SEQuence DTIMe on page 205 Trigger Offset Trigger Source Settings Defines the time offset between the trigger event and the start of the sweep For more information see chapter 4 9 1 Trigger Offset on page 80 offset 0 Start of the sweep is delayed offset 0 Sweep starts earlier pre trigger Remote command TRIGger SEQuence HOLDoff TIME on page 205 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Hysteresis Trigger Source Settings 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
132. EREN AA KEREC AAAA R E NR AREE REER RARN ERRANSA 156 How to Analyze WLAN Signals in a MIMO Measurement Setup 157 How to Determine the OBW SEM ACLR or CCDF for WLAN Signals 162 Optimizing and Troubleshooting the Measurement 164 Optimizing the Measurement Results eene 164 Error Messages and Warnings eese nennen nennen nnn 165 Remote Commands for WLAN Measurements 167 COMMON SUOS t M 167 uge e dl ET 168 Activating WLAN Measurements cccccsseenceeeeeeeeeeeeeeeeeeeeseeeeeeeeeseeeeeeenenseeeneneneeeeanes 173 Selecting a Measurement essen ercer 177 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tol lcu EE 184 Configuring Frequency Sweep Measurements on WLAN Signals 245 Configuring the Result Display eeeeeeeeneneennnnnennn nennen 247 SAA 257 Retrieving ResSultS ciocoiosiiisrnciccinn ercer Ee 261 EI e 289 Status RegiSterS coincide 293 Commands for Compatibility eeeeeeeeeeeeerennenenenen enne nnn 300 Programming Examples R amp S FSW K91 eene 302 Annex FRETTING Me 307 Sample Rate and
133. ETCh BURSt EVM PILot MINimum This command returns the average maximum or minimum EVM in dB for the pilot car rier For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only FETCh BURSt FERRor AVERage FETCh BURSt FERRor MAXimum FETCh BURSt FERRor MINimum This command returns the average maximum or minimum center frequency errors in Hertz For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only FETCh BURSt GIMBalance AVERage FETCh BURSt GIMBalance MAXimum FETCh BURSt GIMBalance MINimum This command returns the average maximum or minimum UO imbalance in dB For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only Retrieving Results FETCh BURSt IQOFfset AVERage FETCh BURSt IQOFfset MAXimum FETCh BURSt IQOFfset MINimum This command returns the average maximum or minimum UO offset in dB For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only FETCh BURSt EVM ALL AVERage FETCh BURSt EVM ALL MAXimum FETCh BURSt EVM ALL MINimum This command returns the average maximum or minimum UO skew in picoseconds For details see chapter 3 1 1 4 1 Q Skew on page 19 Usage Query only FETCh BURSt PAYLoad AVERage FETCh BURSt PAYLoad MINimum FETCh B
134. Expected Input Signal Frontend Parameters on page 79 e put Source Setllligs vetere iain aden 92 o E AE E E 98 e Frogin SONNIE EE 101 WE ale Ee EE 102 5 3 4 1 Input Source Settings The input source determines which data the R amp S FSW will analyze Input settings can be configured in the Input dialog box Some settings are also available in the Amplitude tab of the Amplitude dialog box O The Digital UO input source is currently not available in the R amp S FSW WLAN applica tion e Radio Frequenty Inp lt u corro tente hee ete te ue 93 e Jpigitall G Input Settilig9 1 erc eere ri 94 e Analog Baseband Input Gettinges enne 97 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Radio Frequency Input The default input source for the R amp S FSW is Radio Frequency i e the signal at the RF INPUT connector on the front panel of the R amp S FSW If no additional options are installed this is the only available input source r pes EC OO o won Input Source Power Sensor Probes Radio Frequency On External Input Coupling Mixer Impedance Digital I 9 Q High Pass Filter 1 3 GHz Analog YIG Presclector Baseband Input Connector Radio Frequency Gtate Au 93 DFU US SOM EE 93 dere 93 elle Eed e Me EE 94 MIG EE 94 Radio Frequency State Activates input from the RF INPUT connector Remote command INPut SELect on page 187 Input Coupling Th
135. FSW WLAN application provides two different types of EVM calculation PPDU EVM Direct method The PPDU EVM direct method evaluates the root mean square EVM over one PPDU That is the square root of the averaged error power normalized by the averaged refer ence power N 1 N 1 y IX uisi n Xref n K le n EVM n 0 _ n 0 N 1 N 1 gt ror 1 gt ror 1 n 0 n 0 Before calculation of the EVM tracking errors in the measured signal are compensated for if specified by the user In the ideal reference signal the tracking errors are always compensated for Tracking errors include phase center frequency error common phase error timing Sampling frequency error and gain errors quadrature offset and gain imbalance errors however are not corrected The PPDU EVM is not part of the IEEE standard and no limit check is specified Never theless this commonly used EVM calculation can provide some insight in modulation quality and enables comparisons to other modulation standards WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Fig 3 6 Q diagram for EVM calculation Peak Vector Error IEEE method The peak vector error Peak EVM is defined in section 18 4 7 8 Transmit modulation accuracy of the IEEE 802 11b standard The phase timing and gain tracking errors of the measurement signal center frequency error common phase error sampling fre quency error are compensated for before EVM c
136. INUIT icon E E a rex ce YR en 266 FETCh BURStEVM DATA MINIMUMZ iii iiie en oni onim anao n ata anna nana rap Ra auch ca 266 FETICIBURSEEVMIPIEGEAVERBOSST ucc b o e x eb ade hula 266 FETCHBURSEEVNEPIEoEMAXIDI 3 2 222 22 2 2 2G AA eege 266 FETCHh BURSEEVMEPIEGEMINIIRUIT eio roit denen nine NEES dE 266 FETChBURGCEERRor AVEHRage nana nananananananenanes 266 FETCH BURSEFERROEMAXIMUN conan 266 FETCHBURStEFERROEMINIMUM KEE 266 FETOChBURGGGlMalance AVEhRage nn nnnenanans 266 FETCH BURSEGIMBSlaNCE MAXIM KEE 266 FETCh BURSEGIMBalarice MINImblI uia ooa roo oot eoo n roe AEN 266 FETCIEBURSEIOOPISELAVER 8087 icc tre rau river eee de ge RR EEEE 267 FETCHBURSEIQOFfseEM AXIDIDRTE 5 1 1222 ccumsan eek i er oda c aaa a prm ape sip rei caian 267 FETCHh BURSEIQOFfsetMINITINI cda eriis av cecus tas 267 FEIGIIBURSEEVMEALLOUAVERGAGEOT ae etude coenae swans ENEE ege 267 FETGHBURSEEVM IALE MAXIBYUITID sineret Kees AA diria NEESS ENEE EE A 267 FETCH BURSt EV MEAL MINIMU KE 267 FENCMBURSEPAY Load AVER JE EE 267 FETGHh BURSEPAYLoad MINIIUIT socia a laa ceci 267 FETCHBURSEPAY RER dl re EE 267 FETCMBURSEPEAKEAVERAQG iii aa 267 FETCHBURSEPEAR MINIMUM ains 267 FETCH BURStPEAK MAXIMUMT cacon e narrar parata crac ii daa da 267 FETCHNBURSEPREamble AVERAGE 22 2 tiir rrt AA 267 FETCh BEURSEPREamible MINIWUITI 2 12 c oriri oo oo eee c cid 267 FETCh BURSEPREamble MAXimUtIY 1 ein reecit s
137. LAN IQ Measurement Modulation Accuracy Flatness Tolerance Automatic Settings Some settings can be adjusted by the R amp S FSW automatically according to the current measurement settings and signal characteristics 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 Level 145 Resetting the Automatic Measurement Time Meastime Auto 145 Changing the Automatic Measurement Time Meastime Manual 145 Upper Level Hysteresis eerie breiter Ferri net e ade a T Ere da 145 ENEE 146 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 and the preamplifier for analog baseband input the full scale level are adjusted so the signal to noise ratio is optimized while signal compression clipping and overload conditions are minimized In order to do so a level measurement is performed to determine the optimal reference level Remote command SENSe ADJust LEVel on page 244 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
138. Maximum Usable UO Bandwidth for RF Input 307 VO Data File Format ET EE 312 List of Remote Commands WLAN eene 318 due a 325 User Manual 1173 9357 02 11 4 About this Manual 1 Preface 1 1 About this Manual This WLAN User Manual provides all the information specific to the application All general instrument functions and settings common to all applications and operating modes are described in the main R amp S FSW 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 e chapter 2 Welcome to the WLAN Application on page 9 Introduction to and getting familiar with the application e chapter 3 Measurements and Result Displays on page 13 Details on supported measurements and their result types e chapter 4 Measurement Basics on page 54 Background information on basic terms and principles in the context of the mea surement e chapter 5 Configuration on page 85 and chapter 6 Analysis on page 151 A concise description of all functions and settings available to configure measure ments and analyze results with their corresponding remote control command e chapter 7 1 Import Export Functions on page 152 Description of general functions to import and export raw l Q measurement data e chapter 8 How to Perform Measurem
139. Modulation and Cod ing Scheme MCS index Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display MCS column see Signal Field on page 43 Auto same type as first PPDU A1st All PPDUs using the MCS index identical to the first recognized PPDU are analyzed Auto individually for each PPDU AI All PPDUs are analyzed Meas only the specified MCS M Only PPDUs with the MCS index specified for the MCS Index setting are analyzed Demod all with specified MCS D The MCS Index setting is used for all PPDUs Remote command SENSe DEMod FORMat MCSindex MODE on page 230 MCS Index Defines the MCS index of the PPDUs taking part in the analysis manually This field is enabled for MCS index to use Meas only the specified MCS or Demod all with specified MCS Remote command SENSe DEMod FORMat MCSindex on page 230 Nsts to use Defines the the PPDUs taking part in the analysis depending on their Nsts Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display NSTS column see Signal Field on page 43 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Auto same type as first PPDU A1st All PPDUs using the Nsts identical to the first recognized PPDU are analyzed Auto individually for each PPDU Al All P
140. O IEEE 802 1186 M orco tee re tn nette 137 5 3 8 1 Demodulation IEEE 802 11a g OFDM p The following settings are available for demodulation of IEEE 802 11a g OFDM p signals E Demodulation PDUs to Analyze PSDU Modulation Coded OFDM Coded OFDM BPSK r 1 2 Rate is indicated in Signal Guard Interval Length 16 samples Fig 5 2 Demodulation settings for IEEE 802 11a g OFDM or p standard WLAN IQ Measurement Modulation Accuracy Flatness Tolerance PPDU RE 125 PPDU Format re n EE 125 Channel Bandwidth to measure CBW EEN 126 PSDU Modulation tO TC EE 126 PSDU Modulatioll 1 A a re o v rne 127 PPDU Analysis Mode Defines whether all or only specific PPDUs are to be analyzed Auto same type as first PPDU The signal symbol field i e the PLCP header field of the first recog nized PPDU is analyzed to determine the details of the PPDU All PPDUS identical to the first recognized PPDU are analyzed All subsequent settings are set to Auto mode Auto individually for each PPDU All PPDUs are analyzed User defined User defined settings define which PPDUs are analyzed This setting is automatically selected when any of the subsequent settings are changed to a value other than Auto Remote command SENSe DEMod FORMat BCONtent AUTO on page 230 PPDU Format to measure Defines which PPDU formats are to be included in the analysis Depending on which standards t
141. PDUs are analyzed Meas only the specified Nsts M Only PPDUs with the Nsts specified for the Nsts on page 130 set ting are analyzed Demod all with specified Nsts D The Nsts on page 130 setting is used for all PPDUs Remote command SENSe DEMod FORMat NSTSindex MODE on page 231 Nsts Defines the Nsts of the PPDUs taking part in the analysis This field is enabled for Nsts to use Meas only the specified Nsts or Demod all with specified Nsts Remote command SENSe DEMod FORMat NSTSindex on page 231 STBC Field Defines the PPDUs taking part in the analysis according to the Space Time Block Cod ing STBC field content Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display STBC column see Signal Field on page 43 Auto same type as first PPDU A1st All PPDUs using a STBC field content identical to the first recognized PPDU are analyzed Auto individually for each PPDU Al All PPDUs are analyzed Meas only if STBC field 1 1 Stream M1 IEEE 802 11N Only PPDUs with the specified STBC field content are analyzed Meas only if STBC field 2 2 Stream M2 IEEE 802 11N Only PPDUS with the specified STBC field content are analyzed Demod all as STBC field 1 D1 IEEE 802 11N All PPDUs are analyzed assuming the specified STBC field content Demod all as STBC field 2 D2
142. PDUs are demodulated assuming short guard interval length Demod all as long DL All PPDUs are demodulated assuming long guard interval length Remote command CONFigure WLAN GTIMe AUTO on page 221 CONFigure WLAN GTIMe AUTO TYPE on page 221 CONFigure WLAN GTIMe SELect on page 222 5 3 8 3 Demodulation IEEE 802 11b g DSSS The following settings are available for demodulation of IEEE 802 11b or g DSSS sig nals WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Demodulation PPDUs to Analyze AAA Meas only the specified PPDU Format OIE Trin chun Meas only the specified PSDU Modulation PPDU Format Long PPDU PSDU Modulation PLCP Preamble PLCP Header PSDU 144 bits 48 bits Variable 1 2 5 5 11 Mb s Long PPDU Format Fig 5 4 Demodulation settings for IEEE 802 11b g DSSS signals PPDU Format to measure PSDU Modulation touse cece eee eeeeeeeeeeee ease 132 PPDU e EE 133 PSDUMOdUS ION xo ida 133 PPDU Format to measure PSDU Modulation to use Defines which PPDU formats modulations are to be included in the analysis Depend ing on which standards the communicating devices are using different formats of PPDUS are available Thus you can restrict analysis to the supported formats Note The PPDU format determines the available channel bandwidths For details on supported PPDU formats modulations and channel bandwidths depending on the standard see table 4 1 Auto same type as
143. PERation reg ister bit 5 as well as by a low level signal at the AUX port pin 9 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 lt port gt OTYPe on page 212 Level Output Type Trigger 2 3 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 212 Pulse Length Output Type Trigger 2 3 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 213 Send Trigger Output Type Trigger 2 3 Sends a user defined trigger to the output connector immediately Note that the trigger 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 213 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 4 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 e Select the F
144. PP DW in ic tritt n yet asia era 37 PVT Rising Edge emer rere 38 Result Summary o rrr nm reri ens 52 Result Summary Detailed Result Summary Global AA 41 Result Summary items 2 142 Result Summary items remote sn 290 see also Evaluation methods 13 DIGMAL Field terrre cens Spectrum Flatness a WIGAN EE Result Summary Detailed result display AAA 40 Evaluation method Global result display icon 41 Items to display eiii 142 Items to display remote s 255 Result display rrr nr rts 52 Trace dala tact oi eere cree eire 279 Results AWAM EE 283 AMIEVM surta oreet x cer rc P ah 283 AMPM m 283 Bitstream zi CODE EE 284 Constellation VS Cartier oen 285 Constellation vs symbol 285 Data format remote 276 Evaluating 2 151 EVM vs Cartier 286 FFT Spectrum 287 Group ET EE 287 Magnitude Capture neret cns 279 Numeric remote 262 PvT Full Burst si 287 Result summary 219 Retrieving remote 261 RF remote ve 271 Signal field acia 288 Spectrum FlaMMesS aci 288 Trace remote Trace data query remote Retrieving Numeric results remote AA 262 Results remote EX RE Results remote bees 271 Trace results remote oruinn 276 RF attenuation Auto SOfIKGy ipa teorie i e
145. Peers et e et E EDI FO Dee p A EON zd 298 ERNEST 299 STATus QUEStionable CONDIIOR 2 1 rere tete Pete A oce a eds 298 STATUS QUEStionable ere Ee elle LTE 295 STATUS QUEStionable DIQ ENABIC i iria dad a e FRA ER EEN 296 STATus QUEStionable DIQ NTfRarISILOTD ocius tet rp undae d tsp pe edge ode pe da ree abes 296 STATus QUEStlonable DIQ P T E Ia ul DEE 296 STAT S QUEStionable DIQLEVEN KEE 297 STATus QUEStionable EIMiten NTERansitlon 12 tct rtp ida e 299 STATus QUEStionable EIMit amp n P HERR eessen emere a eria ASA 300 STAT s QUEStionable EIMit amp ns EVENIt cerei terrre e mre a eser ter te rt eco indi 298 STATus QUEStionable N TRarisitioh eegene epp a 299 STATUS QUEStOMable PTIRANSINOMN iieri a 300 STAT s QUEStionable SYNG GONDILOT T 2 1c creuser cn ti aati rra vea FU Reset 298 AE ME lee d le IT 299 STATus QUEStlonable SYNC NTRansiti n ordi EES l ie ll 299 STATus QUEStionable SYNC PTRansition STATUS QUEStionable der E A CL RE 298 STATus QUEStionable EVENI 5 creer eege se ER XE CLE ER e XX e E Ded e Re ERR EHE Ada 298 STATUS QUELE pz gpac T 298 SYSTem PRESet CHANnelpEXECUO luisa Agea 177 SYS RER ele 261 TRACE OSAP CONIA EE 195 TRACe IQ APCon B 195 Rer E RE uioreniiziciidi C 195 TRACE e RE TECH KN E EE 194 TRACCAO DATA MEMO E 279 Ul erac EE 204 TMRAGSSNSEEDAMA associa
146. Q Measurement Modulation Accuracy Flatness Tolerance 5 3 6 Synchronization and OFDM Demodulation Synchronization settings have an effect on which parts of the input signal are pro cessed during the WLAN measurement i yncnro zatic e kal Synchronization Power Interval Search OFDM Demodulation Power Interval Seskei uie ee et titer ee ter reae ei nnt e teat tete eeu EEA ea PER E OUT 121 FET Start Offset rte re re i e E eet e dds 121 Power Interval Search If enabled the R amp S FSW WLAN application initially performs a coarse burst search on the input signal in which increases in the power vs time trace are detected Further time consuming processing is then only performed where bursts are assumed This improves the measurement speed for signals with low duty cycle rates However for signals in which the PPDU power levels differ significantly this option should be disabled as otherwise some PPDUs may not be detected Remote command SENSe DEMod TXARea on page 217 FFT Start Offset This command specifies the start offset of the FFT for OFDM demodulation not for the FFT Spectrum display AUTO The FFT start offset is automatically chosen to minimize the intersym bol interference Guard Interval Cntr Guard Interval Center The FFT start offset is placed to the center of the guard interval Peak The peak of the fine timing metric is used to determine the FFT start offset Remote com
147. QUADoffset MINimum FETCH BURSERMS MAXIMUM 2 sorsra ie 268 FETCh BURSERMS MINIMUM cursi ac cora TEE ei OA vico aaa 268 NS Rer TER RE 268 FETCHBURSESTAR E 263 FETCh BURSESYMBolerror AVERageY c tr rrr ia a a 268 FETCh BURSESYMBolerror MAXimutm o etn ten ee ESA SENG 268 FETCh BURSt SYMBolerror MINimum FETCHIS YMBOl COUNG EE 263 Xe Eug LN KE 276 lee Hin TC 258 INIMiate tee 259 INiTiate SEQuencer EE 259 INIiate ele EE 260 ll MEET 259 dli i ETSI Ie EE iii aia 200 acq MESTRE o BAD UO coito oie 200 INPut ATTen ation PROTection RESOL rr rnt tee epe tree ctl eva pesi tere Ly ut ER ede xt 186 INPU COUPLING Efe Siesctis B 186 elei Dr eile Ver pe 189 INPut _DIQURANGE6 COUPIING BEEN 190 INPUCDIQ RANGELUR PEN inisi tek Erit Ta ve e ak io a 190 INPut DIQ RANGe UPPa r E ALTO eren ec perc re eio teet pee ree ve erexit cien dca persone uev mad 190 ll Te le Ne TEE TN RE 191 INPUEDIO SRA ET INPut DIQ SRATe AUTO lei a EE INPUEEATT AU TO E INPUBEAT TS TA Trios E INPUUEILTERHPASS S TAT NG 186 INPUt FILTerYIGESTAT Elevacion xn ee p ee Edd reo tr ovk a se rx Deed Ci va ue 187 INPULGAINISTIA M INPut GAIN VALue ll helle le INPUtlO BALanced ESTATE citar e Ei Nata 192 INPut IQ FULIE Scale AUTO DE 192 INPUEIO FULESCale MEV el eege eege ia 192 elei D er ag d
148. R amp S FSW has to resample the data During data processing in the R amp S FSW the sample rate usually changes decrea ses The RF input is captured by the R amp S FSW using a high sample rate and is resampled before it is processed by the R amp S FSW WLAN application Remote command TRACe IQ SRATe on page 204 Capture Time Specifies the duration and therefore the amount of data to be captured in the capture buffer If the capture time is too short demodulation will fail Remote command SENSe SWEep TIME on page 203 3 5 2 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Swap UO Activates or deactivates the inverted UO modulation If the and Q parts of the signal from the DUT are interchanged the R amp S FSW can do the same to compensate for it On and Q signals are interchanged Inverted sideband Q j l Off and Q signals are not interchanged Normal sideband I j Q Remote command SENSe SWAPi q on page 203 Suppressing Filter out Adjacent Channels IEEE 802 11a g OFDM ac n p If activated default only the useful signal is analyzed all signal data in adjacent chan nels is removed by the filter This setting improves the signal to noise ratio and thus the EVM results for signals with strong or a large number of adjacent channels However for some measurements information on the effects of adjacent channels on the measured signal may be of in
149. R amp S9FSW K91 WLAN Measurements User Manual 22 Constellation 5 0n s gt rier 250 5 t 04 stn A Clw d ier i i i i D mg H og Config T Symb 1 57 Symb Symb 57 1173 9357 02 11 ROHDE amp SCHWARZ Test amp Measurement User Manual This manual applies to the following R amp S9FSW models with firmware version 2 00 and higher R amp S FSW8 1312 8000K08 R amp S FSW13 1312 8000K13 R amp S FSW26 1312 8000K26 R amp S FSW43 1312 8000K43 R amp S FSW50 1312 8000K50 R amp S FSW67 1312 8000K67 The following firmware options are described R amp S FSW K91 WLAN 802 11a 1313 1500 02 R amp S FSW K91ac WLAN 802 11ac 1313 4209 02 R amp S FSW K91n WLAN 802 11n 1313 1516 02 R amp S FSW K91p WLAN 802 11p 1321 5646 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 2014 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 R amp S is a registered trademark of Rohde amp Schwarz GmbH amp C
150. RACking LEVel SENSe RN le SENSE TRACKING GIE SENSe TRACKING TIME ccr teo ep erret NEEN denen SENSe n DEMod F ORMat SIGSymbol 2 rtr teta rient th nhe ei pino e Ra e cines SENS sBD IPOWSr E CAL Culate LIMit ACPower ACHannel RE Gu 272 CAL Culate LIMit ACPower AL Ternate lt ch gt RESUlP AA 272 CAL Culate EIMIRBU RSA ba ooo ara das da Du RED 239 CALcGulate LIMIEBURSEtALERESUI EE 269 CAL C ulate EIMIEBURSEEVM ALLE MAXImUEn 22 cott rota erc rp dao 239 CAL Culate IM BURGCEVM ALL MAXimum RE Gu 269 CALCulate LIMitiBURSEEVM ALLAVERAGQG iscsi cia res degen 239 CAL Culatel IMC BUIRGCEVMALLTAVERaoelRE Gut 269 CAL Culatel IMC BURGCEVM DATA MAXimum cnn EENS 240 CAL Culatel IMC BUIRGCEVM DATA MAXimum REG 270 CALCulate EIMiItEBURSEtEVM DATA AVMERage erreichten rere cete lees eee nee CALCulate LIMit BURSt EVM DATA AVERage RESult CALGulate EIMiIEBU RSECEEVM PIEOGMAXIIUII ME CAL Culate LIMit BURSt EVM PlLot MAXimum RES Ult osnan 270 CAL Culatel IM BURGCEVM PI ol AVERA JO A 240 CALCulate LIMiItBURStEVM PILot AVERage RESU erisnimien endai 270 CALG late LIMittBURS FERRO MAXIMU M E 240 CAL Culate IMC BURGCEERRor MA Ximum RE Gut 270 CALCulate LIMit BURSt FERRor AVERage CAL Culatel IMC BURGCEERRort AVERaoel RE Gut 270 CAL Culatel IMC BURG lOOFtserMAvimum nano n cana tnn nan nc aran cnn nan n cn rnnnn cn nn aa 241 CAL Culatel IMC BURG IOOFtserMAvimum BEGUE
151. REQ key and then the Frequency Config softkey e Select Input Frontend from the Overview and then switch to the Frequency tab Frequency Center 13 25 GHz Center Freque Stepsize 1 0 MHz reque Offset alo TE ds 101 Center Frequency Stepsiz8 nr adr io ri e d ede 101 Frequency OSet PE 102 Center frequency Defines the normal center frequency of the signal The allowed range of values for the center frequency depends on the frequency span fmax and SPAN pin are specified in the data sheet Remote command SENSe FREQuency CENTer on page 196 Center Frequency Stepsize Defines the step size by which the center frequency is increased or decreased when the arrow keys are pressed When you use the rotary knob the center frequency changes in steps of only 1 10 of the Center Frequency Stepsize The step size can be coupled to another value or it can be manually set to a fixed value Center Sets the step size to the value of the center frequency The used value is indicated in the Value field Manual Defines a fixed step size for the center frequency Enter the step size in the Value field Remote command SENSe FREQuency CENTer STEP on page 197 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Frequency Offset Shifts the displayed frequency range along the x axis by the defined offset This parameter has no effect on the R amp S FSW hardware or on the captured da
152. RSEEVM ALEMAXIRUITI aca itc edo EENS SEN 239 CAL Culate IMC BURGCEVM DATA AVERaoel enema 240 CAL Culate LIMit BURSt EVM DATA MAXiMUM ocoocccccooccnccoonnnoconnnnoncnnnonnnnnonnnnnnonnnnnnnaninnnos 240 CAL Culatel IMC BURG EVM PI ot AVtEhRagoel eene 240 CALCulate LIMIEBURSEEVM PIEGEMAXIDYUI 22 tat ete onam ed vo aaia 240 CALCulate LIMit tBURSt FERRor AVERage eeeess eee eitis 240 CAL Culate IM BURGGEERbRor M ANimum nsaan nnannooaannn1anannnnrarnronrrnrnnrnnrnrnnrerrnrrnnnrennnnnn 240 CALCulate LIMIt BURStIQOFfset AVERage terit ce dice dcneaeespacedeee ban dae hn 241 CAL Culate IM BURGrlOOFtserMAvimum sienn n aE AAR AEE 241 CAL CulateL IM BURGt SvMolerort AVEHRagel nenet etsrrteesrererersrsrnrnrnen rnrn nnne 241 CAL Culate IM BURG SvMolerror MA ximum ener enn sse an n 241 CALCulate LIMit BURSt ALL lt Limits gt This command sets or returns the limit values for the parameters determined by the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 all in one step To define individual limit values use the individual CALCulate lt n gt LIMit lt k gt BURSt commands Note that the units for the EVM and gain imbalance parameters must be defined in advance using the following commands e UNIT EVM on page 268 e UNIT GIMBalance on page 268 Parameters lt Limits gt The parameters are input or output as a list of AS
153. Recognized 3 Analyzed 3 Analyzed Physical Channel 0 PPDUs Min Limit Unit 1 18 IQ Offset Gain Imbalance Quadrature Error enter Freq Error Chip Clock Error Rise Time Fall Time Fig 3 25 Global result summary for IEEE 802 11b g DSSS standards The Result Summary Global contains the following information Note You can configure which results are displayed see On page 142 However the results are always calculated regardless of their visibility e Number of recognized PPDUs e Number of analyzed PPDUs e Number of analyzed PPDUs in entire physical channel if available IEEE 802 11a g OFDM ac n p standards Pilot bit error rate EVM all carriers dB EVM data carriers dB EVM pilot carriers dB Center frequency error Hz Symbol clock error ppm IEEE 802 11b g DSSS standards e Peak vector error e PPDU EVM e Quadrature offset e Gain imbalance User Manual 1173 9357 02 11 42 R amp S FSW K91 Measurements and Result Displays SS SS SS Ss eee eS SS SS SS e Quadrature error e Center frequency error e Chip cock error e Rise time e Fall time e Mean power e Peak power e Crest power For details on the individual results and the summarized values see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Remote command LAY ADD 1 RIGH RSG See LAYout ADD WINDow on page 248 Signal Field This result display shows the
154. S FSW with activated option B160 or U160 I Q Bandwidth Extension sample rate 100 Hz 10 GHz maximum bandwidth 160 MHz Sample rate Maximum UO bandwidth 100 Hz to 200 MHz proportional up to maximum 160 MHz 200 MHz to 10 GHz 160 MHz Sample Rate and Maximum Usable UO Bandwidth for RF Input Usable UO bandwidth UO bandwidths for RF input 160 MHz Activated option B160 U160 150 140 130 120 110 100 90 Dption B80 USO 80 or deactivated option B160 U160 70 60 50 40 Option B40 U40 30 mmm mg LLLA LEEELEELEELELLELLLL oio 828 ves LA LLLI LLL LLLLLLLLLLI deest 10 A extension options or B8 Output sample 10000 rate fon MHz 40 60 80 100 120 140 160 180 200 Fig 1 1 Relationship between maximum usable I Q bandwidth and output sample rate with and with out bandwidth extensions A 1 1 Max Sample Rate and Bandwidth with Activated UO Bandwidth Extension Option B320 U320 Sample rate Maximum UO bandwidth 100 Hz to 400 MHz proportional up to maximum 320 MHz 400 MHz to 10 GHz 320 MHz A 1 2 Sample Rate and Maximum Usable UO Bandwidth for RF Input Usable UO bandwidth UO bandwidths for RF input ctivated option B320 U320 unnm wg EG GG Wi CHT 5 80 120 160 200 240 280 320 360 400 Output sample 10000 rate fon MHz Fig 1 2 Relationship between maximum usable l Q bandwidth and output sample rate for active R amp S FSW B320 Max Sa
155. S Z11 Trigger Unit connections Perform the following configuration on all R amp S FSWs except for the MIMO capture settings step 7 These settings are only required for the master analyzer 1 Press the MODE key on the front panel of the R amp S FSW 10 11 How to Analyze WLAN Signals in a MIMO Measurement Setup Select the WLAN item ES WLAN The R amp S FSW opens a new measurement channel for the WLAN application Select the Overview softkey to display the Overview for a WLAN measurement Select the Signal Description button to select the digital standard EEE 802 11ac or IEEE 802 11n Select the Input Frontend button and then the Frequency tab to define the input signal s center frequency The reference level is adapted automatically Select the Signal Capture button to define how much and which data to capture from the input signal For the master analyzer only Select the MIMO Capture tab to define how the data from the MIMO antennas is to be captured a Forthe DUT MIMO Config select the number of TX antennas data will be transmitted from b Under MIMO antenna Signal Capture Setup select Simultaneous c For each connected R amp S FSW enter the IP address and assign an antenna that this analyzer slave will capture data from d Ensure that the State of each analyzer is On and the connection is estab lished the lights should be green in the dialog box e Connect the assig
156. STAT eC nia E aii 187 INPUteIM POG EE 187 IDNR SEG CE ET 187 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 The command works only if the overload condition has been eliminated first For details on the protection mechanism see chapter 4 7 1 RF Input Protection on page 78 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 93 INPut FILTer HPASs STATe lt State gt Activates an additional internal high pass filter for RF input signals from 1 GHz to 3 GHz This filter is used to remove the harmonics of the R amp S FSW in order to mea sure the harmonics for a DUT for example This function requires option R amp S FSW B13 Note for RF input signals outside the specified range the high pass filter has no effect For signals with a frequency of approximately 4 GHz upwards the harmonics are suppressed sufficiently by the YIG filter Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Toler
157. SW B71 IFPower Second intermediate frequency Not available for input from the Digital Baseband Interface R amp S FSW B17 For input from the Analog Baseband Interface R amp S FSW B71 this parameter is interpreted as BBPower for compatibility reasons IQPower Magnitude of sampled UO data For applications that process l Q data such as the UO Analyzer or optional applications Not available for input from the Digital Baseband Interface R amp S FSW B17 or the Analog Baseband Interface R amp S FSW B71 TIME Time interval BBPower Baseband power for digital input via the Digital Baseband Inter face R amp S FSW B17 Baseband power for digital input via the Digital Baseband Inter face R amp S FSW B17 or the Analog Baseband interface R amp S FSW B71 PSEN External power sensor GPO GP1 GP2 GP3 GP4 GP5 For applications that process l Q data such as the l Q Analyzer or optional applications and only if the Digital Baseband Inter face R amp S FSW B17 is available Defines triggering of the measurement directly via the LVDS connector The parameter specifies which general purpose bit 0 to 5 will provide the trigger data Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance The assignment of the general purpose bits used by the Digital IQ trigger to the LVDS connector pins is provided in Digital 1 Q on page 112 TUNit If activated the measurement is triggered b
158. Se DEMod FORMat BANalyze and SENSe DEMod FORMat BANalyze BTYPe are considered in results analysis RST OFF See PPDU Format to measure PSDU Modulation to use on page 132 10 5 8 Evaluation Range The evaluation range defines which data is evaluated in the result display Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Note that as opposed to manual operation the PPDUs to be analyzed can be defined either by the number of data symbols the number of data bytes or the measurement duration CONFigure BURSEPVT A VERE iia arena 233 EE Lee De ee 233 CONFloure WAN PA oad LENG GR 233 E Lee E RE ee EEN 234 SENSEIBURSECOUN EE 234 SENSe IBURSIECOUNtS TET iiir eher ace e tpa ii andan 235 SENSe DEMod FORMat BANalyze DBYTes EQUal esses 235 SENSe DEMod FORMat BANalyze DBYTes MAX esses nennen nnns 235 SENSe DEMod FORMat BANalyze DBYTes MIN essent 236 SENSe DEMod FORMat BANalyze DURation EQUal essen 236 SENSe DEMod FORMat BANalyze DURation MAX eese nennen 236 SENSe DEMod FORMat BANalyze DURation MIN eese 237 SENSe DEMod FORMat BANalyze S YMBols EQUal esee eene 237 SENSe DEMod FORMat BANalyze SYMBols MAX esses enne nnns 238 SENSe DEMod FORMat BANalyze SYMBols MIN eeeeeeeeeeen eene 238 CONFigure BURSt PVT AVERage Va
159. This format is almost always suitable regardless of the actual data format However the data is not as compact as other for mats may be REAL 32 32 bit IEEE 754 floating point numbers in the definite length block format In the Spectrum application the format setting REAL is used for the binary transmission of trace data For UO data 8 bytes per sample are returned for this format set ting UINT In the R amp S FSW WLAN application bitstream data can be sent as unsigned integers format to improve the data transfer speed compared to ASCII format RST ASCII Example FORM REAL 32 Usage SCPI confirmed Retrieving Results SENSe BURSt SELect lt Value gt This command selects the PPDU for which the trace data is queried using TRACe lt n gt DATA for the EVM vs Symbol and EVM vs Carrier result displays if SENSe BURSt SELect STATe is ON The selected PPDU does not affect the corresponding graphical trace displays Parameters lt Value gt Range 1 to lt statistic count gt RST 1 Example LAY WIND2 REPL EVSY SENS BURS SEL STAT ON SENS BURS SEL 10 TRAC2 DATA TRACE1 Returns the trace results for the PPDU number 10 in window 2 EVM vs Symbol SENSe BURSt SELect STATe State Determines whether a selected PPDU using SENSe BURSt SELect is consid ered or ignored Parameters State ON OFF ON Only the results for the selected PPDU are con
160. This remote control command configures the result display type of window 2 to be Bit stream Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See Bitstream on page 25 CONFigure BURSt STATistics SFleld IMMediate This remote control command configures the result display type of window 2 to be Sig nal Field Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See PLCP Header IEEE 802 11b g GSSS on page 36 See Signal Field on page 43 DISPlay WINDow lt n gt SELect This command sets the focus on the selected result display window This window is then the active window Example DISP WIND1 SEL Sets the window 1 active Usage Setting only Selecting a Measurement 10 4 2 Selecting a Common RF Measurement for WLAN Signals The following commands are required to select a common RF measurement for WLAN signals in a remote environment For details on available measurements see chapter 3 2 Frequency Sweep Measure ments on page 47 The selected measurement must be started explicitely see chapter 10 8 Starting a Measurement on page 257 CONFloure BURG GP Cirum AC IMMedlatel nana nnnnnnnanaran 183 CONFigure BURSt SPECtrum MASK IMMediate eese 183 CONFig re BURStSPECt um OBWidth I MMediate ssi nineniiiiiicnii
161. Tolerance Parameters lt Mode gt FBURst ALL MEASure DEMod FBURst The MCS index of the first PPDU is detected and subsequent PPDUS are analyzed only if they have the same MCS index corresponds to Auto same type as first PPDU ALL All recognized PPDUs are analyzed according to their individual MCS indexes corresponds to Auto individually for each PPDU MEASure Only PPDUs with an MCS index which matches that specified by SENSe DEMod FORMat MCSindex are analyzed DEMod All PPDUs will be analyzed according to the MCS index speci fied by SENSe DEMod FORMat MCSindex RST FBURst Example SENS DEM FORM MCS MODE MEAS SENS DEM FORM MCS 1 Manual operation See MCS Index to use on page 129 SENSe DEMod FORMat NSTSindex lt Index gt Defines the the PPDUs taking part in the analysis depending on their Nsts This command is only available for the IEEE 802 11 ac standard This command is available for DEM FORM NSTS MODE MEAS or DEM FORM NSTS MODE DEM see SENSe DEMod FORMat NSTSindex MODE on page 231 Parameters Index Example SENS DEM FORM NSTS MODE MEAS SENS DEM FORM NSTS 1 Manual operation See Nsts on page 130 SENSe DEMod FORMat NSTSindex MODE Mode Defines the the PPDUS taking part in the analysis depending on their Nsts This command is only available for the IEEE 802 1
162. U payloads must also be the same for each Tx antenna but this is not checked Thus useless results are returned if different data was sent To provide identical PPDU content for each Tx antenna in the measurement you can use the same pseudo random bit sequence PRBS with the same PRBS seed initial bit sequence for example when generating the useful data for the PPDU 4 3 5 Calculating Results When you analyze a WLAN signal in a MIMO setup the R amp S FSW acts as the receiv ing device Since most measurement results have to be calculated at a particular stage in the processing chain the R amp S FSW WLAN application has to do the same decoding that the receive antenna does The following diagram takes a closer look at the processing chain and the results at its individual stages Signal Processing for MIMO Measurements IEEE 802 11ac n Spatial Space Time Transmit DUT Stream Stream Antenna and Signals Signals Signals Precoding Wy d Space Time s EN H E ai R Hpny y Block Code Ma ae ES Hphy Qs STBC sli a Ye Hers ed PNE internal cross talk Channel Flatness i Group Delay Physical Channel Hpny k i 4 Effective Channel Hert Hpny Q i i Channel Flatness Group Delay EVMss EVMsrs 1 Q Offset Burst Power Conventional EVM Conventional EVM Gain Imbalance Crest Factor of Data Carrier of Pilot Carrier Quadrature Offset Data Constellation Pilot Conste
163. URSt PAYLoad MAXimum This command returns the average maximum or minimum of the Payload Power per PPDU in dBm All analyzed PPDUS up to the statistic length take part in the statisti cal evaluation Usage Query only FETCh BURSt PEAK AVERage FETCh BURSt PEAK MINimum FETCh BURSt PEAK MAXimum This command returns the average maximum or minimum of the Peak Power per PPDU in dBm All analyzed PPDUS up to the statistic length take part in the statisti cal evaluation Usage Query only FETCh BURSt PREamble AVERage FETCh BURSt PREamble MINimum FETCh BURSt PREamble MAXimum This command returns the average maximum or minimum of the Preamble Power per PPDU in dBm All analyzed PPDUs up to the statistic length take part in the statisti cal evaluation Usage Query only Retrieving Results FETCh BURSt QUADoffset AVERage FETCh BURSt QUADoffset MAXimum FETCh BURSt QUADoffset MINimum This command returns the average maximum or minimum quadrature offset of sym bols within a PPDU This value indicates the phase accuracy For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only FETCh BURSt RMS AVERage FETCh BURSt RMS MAXimum FETCh BURSt RMS MINimum This command returns the average maximum or minimum RMS power in dBm for all analyzed PPDUs For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame
164. URce on page 209 Trigger 2 3 Defines the usage of the variable TRIGGER INPUT OUTPUT connectors where Trigger 2 TRIGGER INPUT OUTPUT connector on the front panel Trigger 3 TRIGGER 3 INPUT OUTPUT connector on the rear panel Trigger 1 is INPUT only Note Providing trigger signals as output is described in detail in the R amp S FSW User Manual Input The signal at the connector is used as an external trigger source by the R amp S FSW No further trigger parameters are available for the connector WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Output The R amp S FSW 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 212 OUTPut TRIGger lt port gt DIRection on page 212 Output Type Trigger 2 3 Type of signal to be sent to the output Device Trig Default Sends a trigger when the R amp S FSW triggers gered Trigger Sends a high level trigger when the R amp S FSW is in Ready for trig Armed ger state This state is indicated by a status bit in the STATus OPERation reg ister bit 5 as well as by a low level signal at the AUX port pin 9 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 lt port gt
165. VT Reference Power IEEE 802 11b g DSSS seen 141 Peak Vector Error Meas Range IEEE 802 11b g DSSS seeesss 141 PPDU Statistic Count No of PPDUs to Analyze If the statistic count is enabled the specified number of PPDUS is taken into considera tion for the statistical evaluation Sweeps are performed continuously until the required number of PPDUs are available The number of captured and required PPDUs as well as the number of PPDUs detected in the current sweep are indicated as Analyzed PPDUs in the channel bar see Channel bar information on page 11 If disabled all valid PPDUs in the current capture buffer are considered Note that in this case the number of PPDUs contributing to the current results may vary extremely Remote command SENSe BURSt COUNt STATe on page 235 SENSe BURSt COUNt on page 234 Source of Payload Length IEEE 802 11 ac n Defines which signal source is used to determine the payload length of a PPDU Take from Uses the length defined by the signal field Signal Field IEEE 802 11 A P L Signal IEEE 802 11 AC Determines the length of the L signal HT Signal IEEE 802 11 N Determines the length of the HT signal Estimate from signal Uses an estimated length Remote command CONFigure WLAN PAYLoad LENGth SRC on page 233 Equal PPDU Length If enabled only PPDUs with the specified Min Max Payload Length IEEE 80
166. Vergers 77 Settings MIMO Diagramm footer Em 12 Diagrams Evaluation method eren ert corretti 51 Differential input Analog Baseband B71 remote control Analog Baseband BT miii DiglConf Softkey see also R amp S DiglConf 96 Digital Baseband Interface B17 Input Settirigs EE Input status remote D Status FEGISIENS o emer metres Digital UO Enhanced mode ner neni 112 Input connection information essessss 96 Input Settings or ttr rh ren creen 94 Biet Ge E 112 Digital input Connection information nte 96 Digital standatdl eoo crc erret 13 15 Channel bandwidths 126 128 135 Default gestanen rr rrr rr hr qe erint 88 Displayed EE 11 Selecting Se Selecting te WEE 184 Display Configuration softkey sess 87 Understanding rore eren 10 Drop out time Ure 81 113 Duplicating Measurement channel remote 173 E Electronic input attenuation esseeesesess 105 Enhanced mode A a A OL 112 Errors Calculating parameters seseseeees 58 Calculating parameters IEEE 802 11a g OFDM 60 Et EE EE 13 Device connections B17 D 294 ISO EE 20 Gain imbalance 1 Q offset e Ee Phase drift seis dlc HE PPDU levels PRO UIMINO eegene RN 123
167. a tion and can be calculated as lt SampleRate gt lt CaptureTime gt See TRACe 10 SRATe on page 204 and SENSe SWEep TIME on page 203 Parameters lt OffsetSamp gt Offset of the values to be read related to the start of the capture buffer Range 0 to lt NumSamples gt 1 lt NumSamples gt Number of measurement values to be read Range 1 to lt NumSamples gt lt OffsetSa gt RST RST value 10 9 4 Measurement Results for TRACe lt n gt DATA TRACE lt n gt The evaluation method selected by the LAY ADD WIND command also affects the results of the trace data query see TRACe lt n gt DATA TRACE lt n gt Details on the returned trace data depending on the evaluation method are provided here Retrieving Results No trace data is available for the following evaluation methods e Magnitude Capture e Result Summary Global Detailed As opposed to the R amp S FSW base unit the window suffix lt n gt is not considered in the R amp S FSW WLAN application Use the DISPlay WINDow lt n gt SELect to select the window before you query trace results For details on the graphical results of these evaluation methods see chapter 3 1 2 Evaluation Methods for WLAN IQ Measurements on page 21 The following table provides an overview of the main characteristics of the WLAN OFDM symbol structure in the frequency domain for various standards The description of the TRACe results refers to these values t
168. a and the complementary blocks in reverse order applied at the receive antenna Spatial Space Time Transmit Receive Space Time Spatial Streams Streams Antennas Antennas Streams Streams v x 4 Stream 9 4 gt Spatial 9 9 gt Spatial gt un Constellation Parser and d Shave Tne s Encoder with way y Synchroni Decoder with SE Demapper Constellation Matrix Q zation and Matrix Q Demod gt Encoder Guard Decoder Mappa STBC Interval y Y PEN STBC ane Steal Coded Modulation la y Qs p L ip s y Q Combiner Coded Bis Physical Channel Heny l Bits Effective Channel Hey Hpny Q R Hey y Hphy Qs Ha S Fig 4 3 Data flow from the transmit antenna to the receive antenna User Manual 1173 9357 02 11 68 R amp S FSW K91 Measurement Basics 4 3 1 Space Time Block Coding STBC The coded bits to be transmitted are modulated to create a data stream referred to as a spatial stream by the stream parser in the transmitting device under test see fig ure 4 3 The Space Time Block Encoder STBC implements the transmit diversity technique see Basic technologies on page 68 It creates multiple copies of the data streams each encoded differently which can then be transmitted by a number of antennas To do so the STBC encodes only the data carriers in the spatial stream using a matrix Each row in the matrix represents an OFDM symbol and each co
169. a ie br qo dae den ehe roseus 49 Occupied ne Lt EE 49 egi 50 Channel Power ACLR Channel Power ACLR performs an adjacent channel power also known as adjacent channel leakage ratio measurement according to WLAN 802 11 specifications The R amp S FSW measures the channel power and the relative power of the adjacent channels and of the alternate channels The results are displayed in the Result Sum mary Ref Level 7 36 dBm RBW 10 kHz 17dB SWT 100 ms e VBW 300 kHz Mode Aut CF 850 0 MHz 1001 pts 419 0 kHz Span 4 19 MHz 2 Result Summary CDMA 2000 Channel Bandwidth Offset Power T 229 MHz 0 86 dBm Upper 0 86 dBm 79 59 dB 80 34 dB 85 04 dB 83 85 dB For details see chapter 5 4 1 Channel Power ACLR Measurements on page 147 Remote command CONFigure BURSt SPECtrum ACPR IMMediate on page 183 Querying results CALC MARK FUNC POW RES ACP see CALCulate MARKer FUNCtion POWer lt sb gt RESul1t on page 273 CEA AAA wu lcs AAA User Manual 1173 9357 02 11 48 R amp S FSW K91 Measurements and Result Displays El Spectrum Emission Mask The Spectrum Emission Mask SEM measurement determines the power of the WLAN signal in defined offsets from the carrier and compares the power values with a spectral mask specified by the WLAN 802 11 specifications The limits depend on the selected bandclass Thus the performance of the DUT can be tested a
170. able The master analyzer sends a trigger impulse to the Trigger Unit to start the measurement as Soon as all slave analyzers are ready to measure The NOISE SOURCE output of the master analyzer is connected to the Trigger Unit s NOISE SOURCE input Each of the Trigger Unit s TRIG OUT connectors is connected to one of the analyzer s TRIGGER INPUT connectors When the master analyzer sends a signal to the Trigger Unit via its NOISE SOURCE output the Trig ger Unit triggers all analyzers simultaneously via its TRIGGER OUTPUT e Manual mode a trigger is generated by the Trigger Unit and triggers all analyzers simultaneously No connection to the DUT is required Each of the Trigger Unit s TRIG OUT connectors is connected to one of the analyz er s TRIGGER INPUT connectors A trigger signal is generated when you press release the TRIG MANUAL button on the Trigger unit Note In manual mode you must turn on the NOISE SOURCE output of the master analyzer manually see the manual of the analyzer User Manual 1173 9357 02 11 83 Triggered measurements A Trigger Unit is activated in the Trigger Source Settings The required connections between the analyzers the trigger unit and the DUT are visualized in the dialog box The NOISE SOURCE output of the master analyzer must be connected to the Trigger Unit s NOISE SOURCE input for all operating modes to supply the power for the Trig ger Unit For more detailed information on the R amp S FS Z
171. able SYNC register contains application specific information about synchronization errors or errors during pilot symbol detection If any errors occur in this register the status bit 11 in the STATus QUEStionable register is set to 1 Each active channel uses a separate STATus QUEStionable SYNC register Thus if the status bit 11 in the STATus QUEStionable register indicates an error the error may have occurred in any of the channel specific STATus QUEStionable SYNC reg isters In this case you must check the register of each channel to determine which channel caused the error By default querying the status of a register always returns the result for the currently selected channel However you can specify any other chan nel name as a query parameter Status Registers Table 10 16 Meaning of the bits used in the STATus QUEStionable SYNC register Bit No Meaning 0 PPDU not found This bit is set if an IQ measurement is performed and no PPDUs are detected 1 This bit is not used 2 No PPDUs of REQuired type This bit is set if an IQ measurement is performed and no PPDUS of the specified type are detec ted 3 GATE length too small This bit is set if gating is used in a measurement and the gate length is not set sufficiently large enough 4 PPDU count too small This bit is set if a PVT measurement is performed with gating active and there is not at least 1 PPDU within the gate lines 5 Au
172. able for input from the Digital Baseband Interface R amp S FSW B17 Note Electronic attenuation is not available for stop frequencies or center frequencies in zero span gt 13 6 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 201 INPut EATT AUTO on page 201 INPut EATT on page 201 Input Settings Some input settings affect the measured amplitude of the signal as well The parameters Input Coupling and Impedance are identical to those in the Input settings see chapter 5 3 4 1 Input Source Settings on page 92 Preamplifier option B24 Input Settings If option R amp S FSW B24 is installed a pream
173. ager Manual softkey RER input nentes Overload protection Overload protection remote ssssssse 186 REMOTE EE 186 187 RF measurements EI 151 Configuration remote 0 0 0 0 eee eeeeeeeeeeeees 245 Results remote ae Step DY Step iniciara ios RF Power let GE 111 Trigger level remote emn 208 RUN CONT KEV rin 146 RUN SINGLE c M M 146 S Sample Tate rasante ataca elle EE Digital l Q Digital UO remote Displayed EE EK la EE Relationship to bandwidth ne Samples Number 13 15 iM 85 SEM Configuring cdma2000 Programming example ccc aa concede SEQUENCE os Aborting remote Activating remote MOS siet Mode remote Remote nc M Pm ji ei CT ERERRPDR Sequential MIMO capture method eu rrr ene 118 Sequential manual MIMO capture method eu rettet 119 Settings IM 89 Short symbol SS IEEE 802 112 g OFDM sm 56 Signal capturing Duration eoe Duration remote Remote control OTK SY corran sereni inpr taste ec Eo Irae FID ESA Signal description COMUN O RECTORE 91 Remote COntrol seriyi neepa n onere inpr eege seen 184 A geed ee EN eine 230 Signal Field PPDU analysis sssaaa sesno 125 127 134 Result display socorro acond 43 Trace
174. al 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 e NAN 10 2 6 2 10 2 6 3 10 2 6 4 10 2 6 5 Introduction Not a number Represents the numeric value 9 91E37 NAN 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 10 2 2 Long and Short Form on page 169 Querying text parameters When you query text parameters the system returns its short form Example Setting SENSe BANDwidth RESolution TYPE NORMal Query SENSe BANDwidth RESolution TYPE would return NORM Character Strings Strings are alphanumeric characters They have to be in straight quotatio
175. al 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 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 174 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 174 Example INST CRE REPL Spectrum2 IQ IQAnalyzer Replaces the channel named Spectrum2 by a new measure ment channel of type IQ Analyzer named IQAnalyzer INSTrument DELete lt ChannelName gt This command deletes a measurement channel If you delete the last measurement channel the default Spectrum channel is activated 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 spectrum channel with the name Spectrum4 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
176. alculation The standard does not specify a normalization factor for the error vector magnitude To get an EVM value that is independent of the level the R amp S FSW WLAN application normalizes the EVM values Thus an EVM of 100 indicates that the error power on the l or Q channels equals the mean power on the l or Q channels respectively The peak vector error is the maximum EVM over all payload symbols and all active carriers for one PPDU If more than one PPDU is analyzed several analyzed PPDUs in the capture buffer or due to the PPDU Statistic Count No of PPDUs to Analyze setting the Min Mean Max columns show the minimum mean or maximum Peak EVM of all analyzed PPDUs The IEEE 802 11b or g DSSS standards allow a peak vector error of less than 35 In contrary to the specification the R amp S FSW WLAN application does not limit the measurement to 1000 chips length but searches the maximum over the whole PPDU 3 1 2 Evaluation Methods for WLAN IQ Measurements The captured UO data from the WLAN signal can be evaluated using various different methods without having to start a new measurement or sweep Which results are dis played depends on the selected evaluation WLAN UO Measurement Modulation Accuracy Flatness and Tolerance The selected evaluation method not only affects the result display in a window but also the results of the trace data query in remote control see TRACe lt n gt DATA on page 277 All ev
177. aluations available for the selected WLAN measurement are displayed in Smart Grid mode To activate SmartGrid mode do one of the following B Select the SmartGrid icon from the toolbar e Select the Display Config button in the configuration Overview see chapter 5 2 Display Configuration on page 87 e Press the MEAS CONFIG hardkey and then select the Display Config softkey To close the SmartGrid mode and restore the previous softkey menu select the 2 Close icon in the righthand corner of the toolbar or press any key on the front panel E MIMO measurements When you capture more than one data stream MIMO measurement setup see chap ter 4 3 Signal Processing for MIMO Measurements IEEE 802 11ac n on page 67 each result display contains several tabs The results for each data stream are displayed in a separate tab In addition an overview tab is provided in which all data streams are displayed at once in individual subwindows The WLAN measurements provide the following evaluation methods AWAM Em 23 A O shee angina B 23 PIE NW DEE 24 Bitstream orria a ras 25 eccl mM 27 Constellation VS TEE 28 EVM VS Cama UEM 29 STORE ul Em 30 EEN eege 30 FET CUI E 31 Fred Enter vs Preamble eerte eee he SEENEN AEN 32 Group Dolay 33 Magnitud CAPITA Adi 34 Phase Error vs Preamble consi 35 PLGP Header IEEE 802 11D g GO99
178. an first connect an external noise source whose noise power level is known in advance to the R amp S FSW and measure the total noise power From this value you can determine the noise power of the R amp S FSW Then when you measure the power level of the actual DUT you can deduct the known noise level from the total power to obtain the power level of the DUT The noise source is controlled in the Output settings see Noise Source on page 99 Receiving and Providing Trigger Signals Using one of the variable TRIGGER INPUT OUTPUT connectors of the R amp S FSW the R amp S FSW can use a signal from an external reference as a trigger to capture data Alternatively the internal trigger signal used by the R amp S FSW can be output for use by other connected devices Using the same trigger on several devices is useful to syn chronize the transmitted and received signals within a measurement For details on the connectors see the R amp S FSW Getting Started manual User Manual 1173 9357 02 11 78 R amp S FSW K91 Measurement Basics EH External trigger as input If the trigger signal for the R amp S FSW is provided by an external reference the refer ence signal source must be connected to the R amp S FSW and the trigger source must be defined as External on the R amp S FSW Trigger output The R amp S FSW can send output to another device either to pass on the internal trigger signal or to indicate that the R amp S FSW itself i
179. ance Parameters lt State gt ON OFF RST OFF Usage SCPI confirmed Manual operation See High Pass Filter 1 3 GHz on page 94 INPut FILTer YIG STATe State This command turns the YIG preselector on and off Note the special conditions and restrictions for the YIG filter described in YIG Prese lector on page 94 Parameters State ON OFF 0 1 RST 1 0 for UO Analyzer GSM VSA and MC Group Delay measurements Example INP FILT YIG OFF Deactivates the YIG preselector Manual operation See YIG Preselector on page 94 INPut IMPedance Impedance This command selects the nominal input impedance of the RF input 75 Q should be selected if the 50 O input impedance is transformed to a higher impe dance using a matching pad of the RAZ type 25 O in series to the input impedance of the instrument The power loss correction value in this case is 1 76 dB 10 log 750 500 Parameters Impedance 50 75 RST 50 Q Example INP IMP 75 Usage SCPI confirmed Manual operation See Impedance on page 93 See Unit on page 104 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 FSW If no additional options are installed only RF input is supported 10 5 2 2 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Tip The I Q data to be analyzed for WLAN 80
180. annel 0 Complex sample 2 111215 901111215 Channel 1 Complex sample 2 21121 O 121121 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 MATLAB Q Save vector of complex cartesian I Q data i e iqiqiq N 100 iq randn 1 N 13 randn 1 N fid fopen xyz complex float32 w for k 1 length iq fwrite fid single real iq k f10at32 fwrite fid single imag iq k float32 end fclose fid List of Remote Commands WLAN SENSe ADJust CONFigure DU RaltiOn 2 2 tint a 242 SENSe ADJust CONFIgure DURaltior MODE toco rni sth eege eege gege EES 243 SENSe ADJust CONFigure HYS Teresis EO Wer oer re erp een ert e n a enr edu 243 SENSe JADJ st CONFigure HYS l eresis UPB er rrr rnt ari 243 SENSeJADJUStLEVOL e EEEO 244 SENSe BANDwidth CHANnelAUTQO TYPE eot tt t nne nt er nett geri en e 225 SENSe BANDwidth RESolution FIL Ter S TATe essent 203 SENSE BURSE COU jy 234 SENSe BURSECOUNESTA Tesi A ANEN 235 SENSe BURSt SELect SENSe BURSt SELect STATe SENSe IDEMOGQ GESTiRTiatiODi oerte A A enc tte to bc ud pg e d 218 SENSe IDEMOQ EF FOE ESOU iieri vector c daa 217 SENS DEMOG FORMaAEBANALVZG center r
181. annononononononononcncnonnnnnonons 18 19 Reference level ocooooncccccnncccnonccccconccononrccnonancnnnnncnnnnno 104 Options Bandwidth extension oooococccccccococncnccconooonnnnnos 307 308 Electronic attenuation B25 sss 105 High pass filter B13 94 186 Preamplifier B24 retentis 106 OSP switch box Antenna connection MIMO 0ccocciccnicconocccinncnanccnnno 119 P address iii at Setup 5e State MIMO Output Configuration remote one nter 195 Configuration softkey IF frequency remote netten 196 NOISE E 78 99 Parameters cr eerie thee nina 78 Sample rate definition 307 SOMOS sacs icr nter th ri i en 98 MOI iuc emere ias 99 114 Overload siga Tue e as 78 REinpu t remole et eter rci ties 186 Overview Configuring WLAN measurements 89 P Packet search IEEE 802 112 g OFDM sm 56 Parameters A eer eneee E nA aE 79 INPUESIONAN ME 78 A 78 WEAN E 13 Payload Channel estimation oooooocccccncocoocccccconononannnnno 122 218 length eene es 140 141 233 Length source remote enne 233 Length SOUFCB onere depre tornare eene ken n 140 NA aoo rc 56 Peak list Eval ation Method ij crsscescencesconceavcaneuseeneanersarastesaenend 52 Peak vector error Measurement range ue centre preterea 141 Peak Vector Error
182. ansmitted power is not increased the measured powers can be normalised to consider this effect in demodulation 12 Select the Evaluation Range button to define which data in the capture buffer you want to analyze 13 Select the Display Config button and select the displays that are of interest to you up to 16 Arrange them on the display to suit your preferences 14 Exit the SmartGrid mode 15 Return to the Signal Capture MIMO Capture dialog box tab to perform the measurement a Connect the input for the first Tx antenna to the RF input of the R amp S FSW b Select the Single or Cont button for the RX 1 capture buffer to perform a single or continuous measurement for that antenna For a continuous measure ment select the Cont button again to stop the measurement c Connect the input for the second Tx antenna to the RF input of the R amp S FSW d Select the Single Cont button for the RX 2 capture buffer e If necessary repeat these steps for the third and fourth antennas f Select Calc Results to determine the results for each individual data stream in the selected result displays Note Instead of selecting the Single Cont button in the Signal Capture dia log box for each individual antenna capture which requires keeping the dialog box open you can press the RUN SINGLE or RUN CONT key on the front panel to per form the measurements The data is evaluated and the result displays are
183. arameters lt Average gt numeric value Default unit W Usage Query only 10 5 2 4 Configuring the Outputs o Configuring trigger input output is described in Configuring the Trigger Output on page 211 Re Ee ie 196 QUTPUEIFAFFReqQUencY cion A A a 196 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance DIAGnostic SERVice NSOurce lt State gt This command turns the 28 V supply of the BNC connector labeled NOISE SOURCE CONTROL on the front panel on and off For details see chapter 4 7 2 Input from Noise Sources on page 78 Parameters lt State gt ON OFF RST OFF Example DIAG SERV NSO ON Manual operation See Noise Source on page 99 OUTPut IF IFFRequency Frequency This command defines the frequency for the IF output The IF frequency of the signal is converted accordingly This command is available in the time domain and if the IF VIDEO DEMOD output is configured for IF Parameters Frequency RST 50 0 MHz 10 5 3 Frontend Configuration The following commands configure frequency amplitude and y axis scaling settings which represent the frontend of the measurement setup LEE e le 196 Amplitude e 198 10 5 3 1 Frequency SENSE Eege GENT Gi cocina aid deed 196 SENSe TFREQUSnCy CENTERS TEP nerodia tres EES 197 SENSe FREQuency CENTer STEP AUTO cette tenente tette 197 SENSe FREQuesncy
184. are analyzed depending on their guard length if automatic detection is used CONF WLAN GTIM AUTO ON see CONFigure WLAN GTIMe AUTO on page 221 This command is available for IEEE 802 11 n ac standards only Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Note On previous R amp S Signal and Spectrum analyzers this command configured both the guard interval type and the channel bandwidth On the R amp S FSW this com mand only configures the guard type The channel bandwidth of the PPDU to be mea sured must be configured separately using the SENSe BANDwidth CHANnel AUTO TYPE command Parameters lt Type gt FBURst The Gurad interval length of the first PPDU is detected and sub sequent PPDUs are analyzed only if they have the same length corresponds to Auto same type as first PPDU ALL All PPDUs are analyzed regardless of their guard length corre sponds to Auto individually for each PPDU MS Only PPDUs with short guard interval length are analyzed corresponds to Meas only Short in manual operation MN8 MN16 parameters in previous R amp S Signal and Spectrum Ana lyzers ML Only PPDUs with long guard interval length are analyzed corresponds to Meas only Long in manual operation ML16 ML32 parameters in previous R amp S Signal and Spectrum Ana lyzers DS All PPDUs are demodulated assuming short guard interval length corresponds to Demod all as short in manual
185. art of the IEEE 802 11n signal field displayed for convenience see PPDU Format to measure on page 125 MCS Modulation and Coding Scheme MCS index of the PPDU as defined in IEEE Std 802 11 2012 section 20 6 Parameters for HT MCSs CBW Channel bandwidth to measure 0 20 MHz or 40 MHz upper lower 1 40 MHz HT SIG Length Sym Human readable length of payload in OFDM symbols The number of octets of data in the PSDU in the range of 0 to 65 535 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Parameter Description SNRA Smoothing Not Sounding Reserved Aggregation Smoothing 1 channel estimate smoothing is recommended 0 only per carrier independent unsmoothed channel estimate is recommended Not Sounding 1 PPDU is not a sounding PPDU 0 PPDU is a sounding PPDU Reserved Set to 1 Aggregation 1 PPDU in the data portion of the packet contains an AMPDU 0 otherwise STBC Space Time Block Coding 00 no STBC NSTS NSS 0 the difference between the number of spacetime streams NSTS and the number of spatial streams NSS indicated by the MCS Gl Guard interval length PPDU must have to be measured 1 short Gl used after HT training 0 otherwise Ness Number of extension spatial streams Ness see Extension Spatial Streams sounding on page 136 CRC Cyclic redundancy code of bits 0 23 in HT SIG1 and bits 0 9 in HT SIG2 Tail Bits Used to terminate the trellis of the convol
186. asured and evaluated as a single antenna SISO measurement DUT MIMO configuration 1 Tx antenna 4 3 4 1 Sequential MIMO Measurement Sequential MIMO measurement allows for MIMO analysis with a single analyzer by capturing the receive antennas one after another sequentially However sequential MIMO measurement requires each Tx antenna to transmit the same PPDU over time The PPDU content from different Tx antennas on the other hand may be different If this requirement can not be fulfilled use the simultaneous MIMO capture method see chapter 4 3 4 Capturing Data from MIMO Antennas on page 71 In addition the following PPDU attributes must be identical for ALL antennas e PPDU length e PPDU type User Manual 1173 9357 02 11 72 Signal Processing for MIMO Measurements IEEE 802 11ac n e Channel bandwidth e MCS Index e Guard Interval Length e Number of STBC Streams e Number of Extension Streams Thus for each PPDU the Signal Field bit vector has to be identical for ALL antennas same PPDU attributes different PPDU attributes un j j Sg e Deg Rx1 Capture Memory same PPDU atribu m same PPDU attributes different PPDU contents t d 1 rs P MM b different PPDU attributes ok CX x CN A D M Rx2 Capture Memory Fig 4 5 Basic principle of Sequential MIMO Measurement with 2 receive antennas Note that additionally the data contents of the sent PPD
187. ation to use on page 132 SENSe DEMod FORMat BCONtent AUTO lt State gt This command determines whether the PPDUs to be analyzed are determined auto matically or by the user Parameters lt State gt ON The signal field i e the PLCP header field of the first recog nized PPDU is analyzed to determine the details of the PPDU All PPDUs identical to the first recognized PPDU are analyzed OFF Only PPDUs that match the user defined PPDU type and modu lation are considered in results analysis see SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 and SENSe DEMod FORMat BANalyze on page 227 Manual operation See PPDU Analysis Mode on page 125 SENSe DEMod FORMat MCSindex lt Index gt This command specifies the MCS index which controls the data rate modulation and streams for IEEE 802 11n ac standards only see document IEEE 802 11n D11 0 June 2009 This command is required if SENSe DEMod FORMat MCSindex MODE is set to MEAS or DEM Parameters lt Index gt RST 1 Example SENS DEM FORM MCS MODE MEAS SENS DEM FORM MCS 1 Manual operation See MCS Index on page 129 SENSe DEMod FORMat MCSindex MODE lt Mode gt This command defines the PPDUs taking part in the analysis depending on their Modu lation and Coding Scheme MCS index for IEEE 802 11n ac standards only Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and
188. ble SYNC CONDition on page 298 The OPC command should be used after commands that retrieve data so that subse quent commands to change the trigger or data capturing settings are held off until after the data capture is completed and the data has been returned Retrieving Results e Numeric Modulation Accuracy Flatness and Tolerance Results 262 e Numeric Results for Frequency Sweep Measuremenmts sees 271 e Retrieving Trace Results aaa e Er REL seen EE RC 276 e Measurement Results for TRACe lt n gt DATA TRACE xn sess 279 e Importing and Exporting UO Data and Results 288 10 9 1 Numeric Modulation Accuracy Flatness and Tolerance Results The following commands describe how to retrieve the numeric results from the stand ard WLAN measurements The commands to retrieve results from frequency sweep measurements for WLAN sig nals are described in chapter 10 9 2 Numeric Results for Frequency Sweep Measure ments on page 271 PPDU and Symbol Count Results dto 262 e Error Parameter HResuts nennen nnns nn 264 e Limit Check E DEE 269 10 9 1 1 PPDU and Symbol Count Results The following commands are required to retrieve PPDU and symbol count results from the WLAN IQ measurement on the captured UO data see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 a ie H ee EE 262 FETCIVBURSECOUNEALLES enean tinauaeevectaneestshidv
189. ccur until the pulsed signal is over Y v T Drop Out Fig 4 9 Trigger drop out time for falling edge trigger For gated measurements a combination of a falling edge trigger and a drop out time is generally not allowed 4 9 4 Trigger Holdoff The trigger holdoff defines a waiting period before the next trigger after the current one will be recognized R amp S FSW K91 Measurement Basics Frame 1 Frame 2 Holdoff Fig 4 10 Effect of the trigger holdoff See Trigger Holdoff on page 114 4 9 5 Trigger Synchronization Using an R amp S FS Z11 Trigger Unit For MIMO measurements in which the data from the multiple antennas is captured simultaneously by multiple analyzers see Simultaneous Signal Capture Setup on page 117 the data streams to be analyzed must be synchronized in time The R amp S FS Z11 Trigger Unit can ensure that all analyzers start capturing UO data at the same time The Trigger Unit is connected to the DUT and all involved analyzers Then the Trigger Unit can be used in the following operating modes e External mode If the DUT has a trigger output the trigger signal from the DUT triggers all analyzers simultaneously The DUT s TRIGGER OUTPUT is connected to the Trigger Units TRIG INPUT connector Each of the Trigger Unit s TRIG OUT connectors is connected to one of the analyzer s TRIGGER INPUT connectors e Free Run mode This mode is used if no trigger signal is avail
190. cente obe Seed ies 179 GONFigure BURSEEVM ESYMbol IMMediate 1 erri ioter ENSE 179 CONFigure BURSt EVM ESYMbol IMMediate IEEE 802 11b and g DSSS sss 179 CONFigure BURSt PREamble SELect GONFigure BURStPREambleEIMMediate nett rrr da 180 EE Lee e e AE 233 CONFigur BURSEPVT RROW GM searre rid arica cope FEE AA 233 CONFigure BURSEPVT SELeCt iria Az 180 GONFig re BURSEPV T MMediate e pct odi a ia 180 GONFigure BURSEtSPECtrum ACPREIMMediate 2 6 onu ttt en rrr einn nun riter 183 GONFigure BURSt SPECtrum FF T IMMediate 12 rrr rer rre rne rrr rn nee 181 GONFigure BURSESPECtrum FLATness CSELect in titre cn pria eot berba Fh or iii 256 GONFigure BURSESPECtrum FLA Thess SEL6ectL eiii ii iii i ederet 181 CONFigure BURSt SPECtrum FLATness IMMediate 55 orent tont torn 182 CONFigure BURSt SPECtrum MASK IMMediate CONFigure BURSt SPECtrum OBWidth IMMediate CONFigure BURSEtSTATistics BSTReam IMMediate eese 182 CONFigure BURSEtSTATistics CCDF IMMediate a nennen 183 GONFigure BURSESTATistics SFleld IMMediate 2 2 4 toot rene rrr nene 182 GONFigure POWher AU TO icio rettet nr rone aa Py eats CONFigure POWerAU TO E CONFigure POWer AUTO SWEep TIME CONFigure POWerEXPectedRE coria ati EE Lee Re EE GONFigure WLAN ANTMatrix ADDRess add 2 trente mre epa eh
191. control command configures result display type of window 2 to be either Spectrum Flatness or Group Delay Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Parameters lt MeasType gt FLATness GRDelay Example CONF BURS SPEC FLAT SEL FLAT Configures the result display of window 2 to be Spectrum Flat ness CONF BURS SPEC FLAT IMM Performs a default WLAN measurement When the measure ment is completed the Spectrum Flatness results are displayed Usage Event Manual operation See Group Delay on page 33 See Spectrum Flatness on page 46 Selecting a Measurement CONFigure BURSt SPECtrum FLATness IMMediate This remote control command configures the result display in window 2 to be Spectrum Flatness or Group Delay depending on which result display was selected last using CONFigure BURSt SPECtrum FLATness SELect on page 181 Results are only displayed after a measurement is executed e g using the INI Tiate IMMediate command Example CONF BURS SPEC FLAT SEL FLAT Configures the result display of window 2 to be Spectrum Flat ness CONF BURS SPEC FLAT IMM Performs a default WLAN measurement When the measure ment is completed the Spectrum Flatness results are displayed Usage Event Manual operation See Group Delay on page 33 See Spectrum Flatness on page 46 CONFigure BURSt STATistics BSTReam IMMediate
192. crosstalk from various sour ces for example e from the transmission paths inside the DUT e from the connection between the analyzer and the DUT e from the analyzer itself The crosstalk from the analyzer can be neglected If the analyzer and DUT are connec ted by cable this source of crosstalk can also be neglected For further information on crosstalk see chapter 4 3 6 Crosstalk and Spectrum Flatness on page 75 4 3 4 Capturing Data from MIMO Antennas The primary purpose of many test applications that verify design parameters or are used in production is to determine if the transmitted signals adhere to the relevant standards and whether the physical characteristics fall within the specified limits In such cases there is no need to measure the various transmit paths simultaneously Instead they can either be tested as single antenna measurements or sequentially with restrictions see also chapter 4 3 4 1 Sequential MIMO Measurement on page 72 Then only one analyzer is needed to measure parameters such as error vector magnitude EVM power and UO imbalance Measurements that have to be carried out for development or certification testing are significantly more extensive In order to fully reproduce the data in transmit signals or analyze the crosstalk between the antennas for example measurements must be per formed simultaneously on all antennas One analyzer is still sufficient if the system is using transmit diversity
193. curacy Flatness and Tolerance on page 13 is started immediately However you can stop and start a new measurement any time Furthermore you can perform a sequence of measurements using the Sequencer see chapter 5 1 Multiple Measurement Channels and Sequencer Function on page 85 PARDO EE ee 257 CALC latesn gt OR EE EE 258 Nitia CON MUOU E 258 INTiate eR 259 INITlate GEOuencer ABOL 259 IN Tigte SEQUENCER TEEN 259 INITiate SEQUE MODE naaa 260 SYS Tem SEQUENCE oiia aaa a aA a a A A a a a A adaa ae 261 ABORt This command aborts a current measurement 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 WAI command after ABOR and before the next command For details see the Remote Basics chapter in the R amp S FSW User Manual To abort a sequence of measurements by the Sequencer use the INITiate SEQuencer ABORt on page 259 command Note on blocked remote control programs Starting a Measurement 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 FSW is blocked for further commands In this case you must inter rupt processing on the remote channel first in order to abort the measurement To do so send a Device Clear command from the control instrument to
194. d DETected STANdard The pilot sequence is determined according to the correspond ing WLAN standard In case the pilot generation algorithm of the device under test DUT has a problem the non standard con form pilot sequence might affect the measurement results or the WLAN application might not synchronize at all onto the signal generated by the DUT DETected The pilot sequence detected in the WLAN signal to be analyzed is used by the WLAN application In case the pilot generation algorithm of the device under test DUT has a problem the non standard conform pilot sequence will not affect the measure ment results In case the pilot sequence generated by the DUT is correct it is recommended that you use the According to Standard setting because it generates more accurate measure ment results RST STANdard Manual operation See Pilots for Tracking on page 123 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance SENSe TRACking TIME lt State gt Activates or deactivates the compensation for timing drift If activated the measure ment results are compensated for timing error on a per symbol basis Parameters lt State gt ON OFF RST OFF Manual operation See Timing Error Tracking on page 123 10 5 7 Demodulation The demodulation settings define which PPDUs are to be analyzed thus they define a logical filter The available demodulation settings
195. d The EVM results can be calculated more accurately R amp S FSW K91 Optimizing and Troubleshooting the Measurement Accounting for phase drift in the EVM According to the WLAN 802 11 standards the common phase drift must be estimated and compensated from the pilots Thus these deviations are not included in the EVM To include the phase drift disable Phase Tracking see Phase Tracking on page 123 Analyzing time jitter Normally a symbol wise timing jitter is negligible and not required by the IEEE 802 11a measurement standard 6 and thus not considered in channel estimation However there may be situations where the timing drift has to be taken into account However to analyze the time jitter per symbol enable Timing Tracking see Timing Error Tracking on page 123 Compensating for non standard conform pilot sequences In case the pilot generation algorithm of the device under test DUT has a problem the non standard conform pilot sequence might affect the measurement results or the WLAN application might not synchronize at all onto the signal generated by the DUT In this case set the Pilots for Tracking to Detected see Pilots for Tracking on page 123 so that the pilot sequence detected in the signal is used instead of the sequence defined by the standard However if the pilot sequence generated by the DUT is correct it is recommended that you use the According to Standard setting because it genera
196. d by stream sym bol and carrier IESSE User Manual 1173 9357 02 11 25 R amp S FSW K91 Measurements and Result Displays Stream 1 4 Stream 1 Stream2 Stream3 Stream 4 3 2 Stream 2 Carrier Symbol 1 gt Carrier 01110110 122 01110101 119 Symbol 1 11001110 01110011 10100111 122 01001010 10010110 11100000 119 11111101 10010010 01100010 11100001 116 10010011 00110000 10000110 116 01000011 01110001 00101110 10000100 11111110 01110101 01111110 113 10110010 10011010 11100110 10001111 113 11000101 00010010 11101101 01111010 110 10010101 00100101 10100100 110 107 10001011 00011011 01001010 107 104 10100100 HI 10111101 104 00001001 0 11011100 101 00111000 10110011 E 101 11100010 00110011 10101111 3 3 Stream 3 3 4 Stream 4 Carrier Symbol 1 Carrier 11001110 122 00010010 119 10101111 Symbol 1 01001101 11100110 01110110 00110011 122 11001101 00111101 10111011 119 11101001 00100011 00000111 00001011 00001011 10101000 116 00000001 00101101 10100010 116 01011101 113 01010001 10011000 113 00010010 01101101 01000000 11100010 110 10000010 11101011 11100100 110 00011101 00000010 107 01001111 11101100 11001101 107 01000010 01000111 00111110 0 01001111 104 10010001 0 01010000 104 11001001 101 00101101 01010011 i 101 11001101 01001101 Fig 3 8 Bitstream result display for IEEE 802 11n MIMO measurements For single carrier measurements IEEE 802 11b g DSSS
197. d in OFDM symbols EECH User Manual 1173 9357 02 11 43 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Parameter Description P Parity bit Signal Tail Signal tail preset to 0 Table 3 6 Demodulation parameters and results for Signal Field result display IEEE 802 11ac Parameter Description Format PPDU format used for measurement Not part of the IEEE 802 11ac signal field displayed for convenience see PPDU Format to measure on page 125 MCS Modulation and Coding Scheme MCS index of the PPDU as defined in IEEE Std 802 11 2012 section 20 6 Parameters for HT MCSs BW Channel bandwidth to measure 0 20 MHz 1 40 MHz 2 80 MHz 3 8080 MHz and 160MHz L SIG Length Sym Human readable length of payload in OFDM symbols STBC Space Time Block Coding 0 no spatial streams of any user has space time block coding 1 all spatial streams of all users have space time block coding GI Guard interval length PPDU must have to be measured 1 short guard interval is used in the Data field 0 short guard interval is not used in the Data field Ness Number of extension spatial streams Ngss see Extension Spatial Streams sounding on page 136 CRC Cyclic redundancy code Table 3 7 Demodulation parameters and results for Signal Field result display IEEE 802 11n Parameter Description Format PPDU format used for measurement Not p
198. d in this manual are the same as in the base unit and are described in the R amp S FSW User Manual The latest version is available for download at the product homepage http www2 rohde schwarz com product FSW html Installation You can find detailed installation instructions in the R amp S FSW Getting Started manual or in the Release Notes 2 1 Starting the WLAN Application The WLAN measurements require a special application on the R amp S FSW R amp S FSW K91 Welcome to the WLAN Application To activate the WLAN application 1 Press the MODE key on the front panel of the R amp S FSW A dialog box opens that contains all operating modes and applications currently available on your R amp S FSW 2 Select the WLAN item gt TT WLAN The R amp S FSW opens a new measurement channel for the WLAN application The measurement is started immediately with the default settings It can be configured in the WLAN Overview dialog box which is displayed when you select the Overview softkey from any menu see chapter 5 3 2 Configuration Overview on page 89 2 2 Understanding the Display Information The following figure shows a measurement diagram during analyzer operation All information areas are labeled They are explained in more detail in the following sec tions MultiView Spectrum WLAN Sampling Rate Fs 320 0 MHz Standard 3 Capt Time No of Samples Sms PPDU MCS Index GI Meas Setup 1 1 Rx No of Data Symbols
199. d x axis 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 Click on a displayed warning or error message to obtain more details see also WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 3 Measurements and Result Displays The R amp S FSW WLAN application provides several different measurements in order to determine the parameters described by the WLAN 802 11 specifications For details on selecting measurements see Selecting the measurement type on page 85 e WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 13 e Frequency Sweep MEasurBmMents roter eene ttl d Re choc nn ene etd 47 3 1 WLAN UO Measurement Modulation Accuracy Flat ness and Tolerance The default WLAN UO measurement captures the UO data from the WLAN signal using a nearly rectangular filter with a relatively large bandwidth The UO data captured with this filter includes magnitude and phase information which allows the R amp S FSW WLAN application to demodulate broadband signals and determine various character istic signal parameters such as the modulation accuracy spectrum flatness center fre quency tolerance and symbol clock tolerance in just one measurement Other parameters specified in the WLAN 802 11 standard requir
200. data 288 signal level E 104 Signal processing IEEE 802 11a g OFDM m 54 IEEE 802 11b g DSSS EE 61 Signal source une 187 Simultaneous MIMO capture method rtt rennen 117 Single Sequencer dc H 86 Single sweep led 146 SISO ME 67 SKEW enuresis 19 Slave analyzers IP address MIMO State MIMO icons rain iaa Slope lee GE 114 209 SmartGFid WE 22 87 softkey Average Length K91 91n sess 141 Ref Pow Max Mean K91 91n 141 Signal Field KIWI vous 36 Softkeys Amiplit de Conflg EE 102 Auto Level voca 105 145 EEN 112 eu 235101 Continue Single Sweep 146 Continuous SequencCer cooocccccooccccconcccnonancnnnnncnnnanacancnno 86 Continuous Sweep 146 DIGI GON ice rrr tte rcr nce 96 Digital Qr etr cia 112 Display Config me ttes 87 Export sissies we 153 External 2 140 Free Run ate 1410 Frequency Config 101 VQ POW M EE 111 IF e EE 110 Import Sp Input Source Config E ER IQ EXDOFE EE 153 IQ Import ene 153 Lower Level Hysteresis 146 Meastime Auto 145 Meastime Manual 145 Outputs GONG a codec o rd eee per ntes 98 Power Sensor aiii 112 Pre MP M 106 Ref Level Offset 104 Repetition interval dd Result Config we 142
201. data for all antennas sequentially and calculates and displays the results individually for each data stream in the selected result displays automati cally A single analyzer and the Rohde amp Schwarz OSP Switch Platform is required to measure the multiple DUT Tx antennas the switch platform must be fitted with at least one R amp SGOSP B101 option the number depends on the number of Tx antennas to measure The IP address of the OSP and the used module configu ration bank must be defined on the analyzer the required connections between the DUT Tx antennas the switch box and the analyzer are indicated in the MIMO Signal Capture dialog box For important restrictions concerning sequential measurement see chap ter 4 3 4 1 Sequential MIMO Measurement on page 72 e Sequential using manual operation The data streams are captured sequentially by a single analyzer The antenna sig nals must be connected to the single analyzer input sequentially by the user In the R amp S FSW WLAN application individual capture buffers are provided and displayed for each antenna input source so that results for the individual data streams can be calculated The user must initiate data capturing for each antenna and result calculation for all data streams manually For important restrictions concerning sequential measurement see chap ter 4 3 4 1 Sequential MIMO Measurement on page 72 e Single antenna measurement The data from the Tx antenna is me
202. diate cao eno a ren threat 213 OUTPut TRIGger sport PULSe ENGLh 2 1 2 2 2 2 222 x Lure ans 213 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance OUTPut TRIGger lt port gt DIRection Direction This command selects the trigger direction Suffix lt port gt Selects the trigger port to which the output is sent 2 trigger port 2 front 3 trigger port 3 rear Parameters lt Direction gt INPut Port works as an input OUTPut Port works as an output RST INPut Manual operation See Trigger 2 3 on page 99 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 TRIGger port OTYPe Suffix port Selects the trigger port to which the output is sent 2 trigger port 2 front 3 trigger port 3 rear Parameters lt Level gt HIGH TTL signal LOW OV RST LOW Manual operation See Trigger 2 3 on page 99 See Level on page 100 OUTPut 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 trigger port 2 front 3 trigger port 3 rear Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt OutputTy
203. e State This remote control command specifies whether an amplification of the signal power due to the spatial mapping is performed according to the matrix entries If this com mand it set to ON then the spatial mapping matrix is scaled by a constant factor to obtain a passive spatial mapping matrix which does not increase the total transmitted power If this command is set to OFF the normalization step is omitted Parameters State Manual operation See Power Normalise on page 138 CONFigure WLAN SMAPping TX lt ch gt STS I lt STS Q gt lt STS I sSTS Q gt lt TimeShift gt This remote control command specifies the mapping for all streams real amp imaginary data pairs and timeshift for a specified antenna Parameters lt STS I Imag part of the complex element of the STS Stream lt STS Q gt Real part of the complex element of the STS Stream Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance lt TimeShift gt Time shift for specification of user defined CSD cyclic delay diversity for the Spatial Mapping Range 32 ns to 32 ns Default unit ns Example CONF WLAN SMAP TX 1 0 1 0 2 0 2 0 3 0 3 0 4 0 4 0 1e 9 Manual operation See User Defined Spatial Mapping on page 139 CONFigure WLAN SMAPping TX lt ch gt STReams lt stream gt STS I lt STS Q gt This remote control command specifies the mapping for a specific stream and antenna Parameters lt STS
204. e CBW Defines the channel bandwidth of the PPDUs taking part in the analysis Depending on which standards the communicating devices are using different PPDU formats and channel bandwidths are supported For details on supported PPDU formats and channel bandwidths depending on the standard see table 4 1 Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display CBW column see Signal Field on page 43 Auto same type as first PPDU A1st The channel bandwidth of the first valid PPDU is detected and subse quent PPDUs are analyzed only if they have the same channel band width Auto individually for each PPDU Al All PPDUs are analyzed regardless of their channel bandwidth Meas only signal M Only PPDUs with the specified channel bandwidth are analyzed Demod all as signal D All PPDUs are assumed to have the specified channel bandwidth Remote command SENSe BANDwidth CHANnel AUTO TYPE on page 225 MCS Index to use Defines the PPDUs taking part in the analysis depending on their Modulation and Cod ing Scheme MCS index Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display MCS column see Signal Field on page 43 Auto same type as first PPDU A1st All PPDUs using the MCS index identical to the first recognized PPDU are ana
205. e see Format element and DataType element To allow reading and writing of streamed UO data all data is interleaved i e complex values are interleaved pairs of and Q values and multi channel signals contain interleaved complex sam 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 I 1 Real sample 1 UO Data File Format iq tar I 2 Real sample 2 Example Element order for complex cartesian data 1 channel I 0 QTO Real and imaginary part of complex sample 0 I 1 O 1 Real and imaginary part of complex sample 1 I 2 2 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 Phi 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 no time index 01 0 QI01 0 Channel 0 Complex sample 0 1 0 Q 1 0 Channel 1 Complex sample 0 2 0 Q 2 0 Channel 2 Complex sample 0 0 11 Q 0 1 Channel 0 Complex sample 1 ITT O FD 111 Channel 1 Complex sample 1 2 1 1 Q 21 1 Channel 2 Complex sample 1 0 21 Q 0 2 Ch
206. e Auto softkey Meastime Manual softkey Remote ul de EEN Auto track time Remote Control init lines 242 Bandwidth Exterision opliOrs 1 0 certet tenete Maximtumiusable iso ene Meng Relationship to sample rate BB Power Trigger SOftKey vacia 112 Bit error rate BER Dil 13 Bitstream Result display sosa ladito 25 Trace data reni innt eiecit 283 Block diagram IEEE 802 112 g OFDM iier itn teen 54 C Capture buffer ACCU cM e 34 Capture buffers Clearing MIMO Used MIMO Capture time Bc pd a aae H Displayed sse eet ceni desees iet ceo aes see also Measurement time ssussssss 203 Carriers Dog aaa 15 CCDF Configuring cdma2000 sss 150 Results etes 50 Trace data 284 Center frequency 101 Analog Baseband DI 98 eat seess Errores Softkey sl EE Channel Estimating Estimating IEEE 802 11a g OFDM 60 Channel bandwidth CBW Default italia 88 PPDU eene 125 126 128 132 134 135 225 Channel bar Displayed information eee 11 Channel estimation Default eit tet DEET 88 Remote Control ii ete aa 218 Channel power AGER see ACER unit 48 Channels elen TEE AWGN IEEE 802 11a g OFDM ETIGCUVO 2c cct adictos Ph
207. e H in FFT represents the channel at the long symbol of the preamble Consequently the frequency deviation A frest not yet compensated produces a phase drift between the long symbol and the first symbol of the payload Therefore this phase drift appears as a constant value DC value in dY R amp S FSW K91 Measurement Basics Tracking the phase drift timing jitter and gain Referring to the IEEE 802 11a g OFDM measurement standard chapter 17 3 9 7 Transmit modulation accuracy test 6 the common phase drift phase emmon must be estimated and compensated from the pilots Therefore this symbol wise phase tracking is activated as the default setting of the R amp S FSW WLAN application see Phase Tracking on page 123 Furthermore the timing drift in FFT is given by phase 9 2gx N Nx xkxl Timing drift 4 3 with amp the relative clock deviation of the reference oscillator Normally a symbol wise timing jitter is negligible and thus not modeled in Timing drift However there may be situations where the timing drift has to be taken into account This is illustrated by an example In accordance to 6 the allowed clock deviation of the DUT is up to max 20 ppm Furthermore a long packet with 400 symbols is assumed The result of FFT and Timing drift is that the phase drift of the highest sub carrier k 26 in the last symbol nof symbols is 93 degrees Even in the noise free case this would lead to s
208. e Modulation Accuracy Flatness and Tolerance Parameters for p ESI 156 e How to Analyze WLAN Signals in a MIMO Measurement Setup 157 e How to Determine the OBW SEM ACLR or CCDF for WLAN Signals 162 8 1 How to Determine Modulation Accuracy Flatness and Tolerance Parameters for WLAN Signals 1 Press the MODE key on the front panel of the R amp S FSW A dialog box opens that contains all operating modes and applications currently available on your R amp S FSW 2 Select the WLAN item 5 WLAN The R amp S FSW opens a new measurement channel for the WLAN application 3 Select the Overview softkey to display the Overview for a WLAN measurement 4 Select the Signal Description button to define the digital standard to be used 5 Select the Input Frontend button and then the Frequency tab to define the input signal s center frequency The reference level is adapted automatically 6 Select the Signal Capture button to define how much and which data to capture from the input signal 7 To define a particular starting point for the FFT or to improve the measurement speed for signals with a low duty cycle select the Synchronization OFDM Demod button and set the required parameters 8 Select the Tracking Channel Estimation button to define how the data channels are to be estimated and which distortions will be compensated for 9 Select t
209. e RF input of the R amp S FSW can be coupled by alternating current AC or direct cur rent DC This function is not available for input from the Digital Baseband Interface R amp S FSW B17 or from the Analog Baseband Interface R amp S FSW B71 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 page 186 Impedance The reference impedance for the measured levels of the R amp S FSW can be set to 50 O or75 0 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 75 Q should be selected if the 50 O input impedance is transformed to a higher impe dance using a 75 Q adapter of the RAZ type 25 O in series to the input impedance of the instrument The correction value in this case is 1 76 dB 10 log 750 500 This function is not available for input from the Digital Baseband Interface R amp S FSW B17 or from the Analog Baseband Interface R amp S FSW B71 For analog baseband input an impedance of 50 Q is always used Remote command INPut IMPedance on page 187 High Pass Filter 1 3 GHz Activates an additional internal high pass filter for RF input signals from 1 GHz
210. e a better signal to noise level or a smaller bandwidth filter than the UO measurement provides and must be determined in separate measurements see chapter 3 2 Frequency Sweep Meas urements on page 47 e Modulation Accuracy Flatness and Tolerance Parameiers A 13 e Evaluation Methods for WLAN IQ Measurements 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters The default WLAN UO measurement Modulation Accuracy Flatness captures the UO data from the WLAN signal and determines all the following UO parameters in a single sweep Table 3 1 WLAN I Q parameters for IEEE 802 11a g OFDM ac n p Parameter Description Sample Rate Fs Input sample rate PPDU Type of analyzed PPDUs MCS Index Modulation and Coding Scheme MCS index of the analyzed PPDUs Gl Guard interval length for current measurement Standard Selected WLAN measurement standard the limits can be changed via remote control not manually see chapter 10 5 9 Limits on page 238 in this case the currently defined limits are displayed here WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Parameter Meas Setup Description Number of Transmitter Tx and Receiver Rx channels used in the measure ment Capture time Duration of signal capture No of Samples Number of samples captured No of Data Symbols The minimum and maximum number of data symbols that a PPDU may have
211. e control command specifies the state of the receive path Note it is not possible to set the state of ANTMatrix1 Master Parameters lt State gt ON OFF State of the receive path Manual operation See State on page 117 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance CONFigure WLAN DUTConfig lt NoOfAnt gt This remote control command specifies the number of antennas used for MIMO mea surement Parameters lt NoOfAnt gt TX1 TX2 TX3 TX4 TX5 TX6 TX7 TX8 TX1 one antenna TX2 two antennas etc RST TX1 Example CONF WLAN DUTC TX1 Manual operation See DUT MIMO Configuration on page 116 CONFigure WLAN MIMO CAPTure lt SignalPath gt Specifies the signal path to be captured in MIMO sequential manual measurements Subsequently use the INITiate IMMediate command to start capturing data Parameters lt SignalPath gt RX1 RX2 RX3 RX4 RX5 RX6 RX7 RX8 For details see Manual Sequential MIMO Data Capture on page 119 RST RX1 Example CONFigure WLAN MIMO CAPTure RX2 INIT IMM Starts capturing data from the receive antenna number 2 Manual operation See Single Cont on page 120 CONFigure WLAN MIMO CAPTure BUFFer lt SignalPath gt Specifies the signal path to be captured in MIMO sequential manual measurements and immediately starts capturing data Parameters lt SignalPath gt RX1 RX2 RX3 RX4 RX5 RX6 RX7 RX8 For detai
212. e phase offset O Og the variation parameters of the IQ offset h i the coefficients of the transmitter filter 4 2 2 Calculation of Signal Parameters The frequency offset the phase offset and the IQ offset are estimated jointly with the coefficients of the transmit filter to increase the estimation quality Once the transmit filter is known all other unknown signal parameters are estimated with a maximum likelihood based estimation which minimizes the cost function N 1 Z 2 _ j2nf A atm atm L Y r v Z xe lav ed _ 9 xs v Ba x Salv Ago x Soll 0 j a v 0 Cost function for signal parameters 4 10 where 9 go the variation parameters of the gain used in the l Q branch Aga the crosstalk factor of the Q branch into the Lbranch S v So v the filtered reference signal of the 1 Q branch The unknown signal parameters are estimated in a joint estimation process to increase the accuracy of the estimates Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS The accurate estimates of the frequency offset the gain imbalance the quadrature error and the normalized UO offset are displayed by the measurement software Gain imbalance UO offset quadrature error The gain imbalance is the quotient of the estimates of the gain factor of the Q branch the crosstalk factor and the gain factor of the I branch 9a Aga 9 Gain imbalance Gain imbalance 4 11
213. e sources are useful when you are measuring power levels that fall below the noise floor of the R amp S FSW itself for example when measuring the noise level of a DUT For details see chapter 4 7 2 Input from Noise Sources on page 78 Remote command DIAGnostic SERVice NSOurce on page 196 Trigger 2 3 Defines the usage of the variable TRIGGER INPUT OUTPUT connectors where Trigger 2 TRIGGER INPUT OUTPUT connector on the front panel Trigger 3 TRIGGER 3 INPUT OUTPUT connector on the rear panel Trigger 1 is INPUT only Note Providing trigger signals as output is described in detail in the R amp S FSW User Manual WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Input The signal at the connector is used as an external trigger source by the R amp S FSW No further trigger parameters are available for the connector Output The R amp S FSW 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 212 OUTPut TRIGger lt port gt DIRection on page 212 Output Type Trigger 2 3 Type of signal to be sent to the output Device Trig Default Sends a trigger when the R amp S FSW triggers gered Trigger Sends a high level trigger when the R amp S FSW is in Ready for trig Armed ger state This state is indicated by a status bit in the STATus O
214. e start of each sweep for Modulation Accuracy Flatness Tolerance measurements This function is only considered for TRIG SEQ SOUR IFP and TRIG SEQ SOUR RFP See TRIGger SEQuence SOURce on page 209 In order to define the trigger level manually switch this function off and define the level using TRIGger SEQuence LEVel IFPower on page 207 or TRIGger SEQuence LEVel RFPower on page 208 Parameters for setting and query lt State gt OFF Switches the auto level detection function off ON Switches the auto level detection function on RST ON Manual operation See Trigger Level Mode on page 113 TRIGger SEQuence LEVel RFPower lt TriggerLevel gt This command defines the power level the RF input must exceed 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 The input signal must be between 500 MHz and 8 GHz For details on the trigger source see Trigger Source Settings on page 109 Parameters lt TriggerLevel gt For details on available trigger levels and trigger bandwidths see the data sheet RST 20 dBm Example TRIG LEV RFP 30dBm Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Manual operation See Trigger Level on page 113 TRIGger SEQuence SLOPe lt Type gt For external and time d
215. ean power of the signal also called Peak to Average Power Ratio PAPR the limits can be changed via remote control not manually see chapter 10 5 9 Limits on page 238 in this case the currently defined limits are displayed here Table 3 2 WLAN I Q parameters for IEEE 802 11b or g DSSS Parameter Description Sample Rate Fs Input sample rate PPDU Type of the analyzed PPDU Data Rate Data rate used for analysis of the signal SGL Indicates single measurement mode as opposed to continuous Standard Selected WLAN measurement standard Meas Setup Number of Transmitter Tx and Receiver Rx channels used in the measure ment Capture time Duration of signal capture No of Samples Number of samples captured sample rate capture time No of Data Symbols The minimum and maximum number of data symbols that a PPDU may have if it is to be considered in results analysis Analyzed PPDUs For statistical evaluation of PPDUs see PPDU Statistic Count No of PPDUs to Analyze on page 140 lt x gt PPDUs of totally required lt y gt PPDUs have been analyzed so far lt z gt indicates the number of analyzed PPDUs in the most recent sweep Number of recognized Number of PPDUs recognized in capture buffer PPDUs global Number of analyzed Number of analyzed PPDUs in capture buffer PPDUs global Number of analyzed Number of PPDUs analyzed in entire signal if available PPDUS i
216. easurement analysis Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance If the SENSe DEMod FORMat BANalyze DURation EQUal command is set to true then this command has no effect Parameters lt Duration gt RST 5464 Default unit us Manual operation See Min Max Payload Length IEEE 802 11b g DSSS on page 141 SENSe DEMod FORMat BANalyze DURation MIN lt Duration gt For IEEE 802 11b and g DSSS signals only If the SENSe DEMod FORMat BANalyze DURation EQUal command is set to true then this command specifies the exact duration required for a PPDU to take part in measurement analysis If the SENSe DEMod FORMat BANalyze DURation EQUal command is set to false this command specifies the minimum duration required for a PPDU to take part in measurement analysis Parameters lt Duration gt RST 1 Default unit us Manual operation See Min Max Payload Length IEEE 802 11b g DSSS on page 141 SENSe DEMod FORMat BANalyze SYMBols EQUal State For IEEE 802 11a g OFDM ac n p signals only If enabled only PPDUs with a specific number of symbols are considered for mea surement analysis If disabled only PPDUs whose length is within a specified range are considered The number of symbols is specified by the SENSe DEMod FORMat BANalyze SYMBols MIN command A range of data symbols is defined as a minimum and
217. ecified format are analyzed Demod all as D All PPDUs are assumed to have the specified PPDU format Remote command SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 SENSe DEMod FORMat BANalyze on page 227 Channel Bandwidth to measure CBW Defines the channel bandwidth of the PPDUS taking part in the analysis Depending on which standards the communicating devices are using different PPDU formats and channel bandwidths are supported For details on supported PPDU formats and channel bandwidths depending on the standard see table 4 1 Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display CBW column see Signal Field on page 43 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Auto same type as first PPDU A1st The channel bandwidth of the first valid PPDU is detected and subse quent PPDUs are analyzed only if they have the same channel band width Auto individually for each PPDU Al All PPDUs are analyzed regardless of their channel bandwidth Meas only signal M Only PPDUs with the specified channel bandwidth are analyzed Demod all as signal D All PPDUs are assumed to have the specified channel bandwidth Remote command SENSe BANDwidth CHANnel AUTO TYPE on page 225 MCS Index to use Defines the PPDUs taking part in the analysis depending on their
218. ectrum test scenarios can be determined by the standard measurements provided in the R amp S FSW base unit Spectrum application These measurements are performed using a much narrower bandwidth filter and they capture only the power level magnitude which we refer to as RF data of the signal as opposed to the two components provided by I Q data Frequency sweep measurements can tune on a constant frequency Zero span mea surement or sweep a frequency range Frequency sweep measurement The signal cannot be demodulated based on the captured RF data However the required power information can be determined much more precisely as more noise is filtered out of the signal User Manual 1173 9357 02 11 47 R amp S9FSW K91 Measurements and Result Displays 3 2 1 The Frequency sweep measurements provided by the R amp S FSW WLAN application are identical to the corresponding measurements in the base unit but are pre config ured according to the requirements of the selected WLAN 802 11 standard For details on these measurements see the R amp S FSW User Manual The R amp S FSW WLAN application provides the following frequency sweep measure ments Measurement Types and Results for Frequency Sweep Measure ments The R amp S FSW WLAN application provides the following pre configured frequency Sweep measurements GhamelPower AGR 2 e eere ert oponen A RECETA RR Te er aa aa 48 Specuum Emission Mask recede tit re eee R
219. ed Note For R amp S power sensors the Gate Mode Lv is not supported The signal sent by these sensors merely reflects the instant the level is first exceeded rather than a time period However only time periods can be used for gating in level mode Thus the trigger impulse from the sensors is not long enough for a fully gated measurement the measurement cannot be completed Remote command TRIG SOUR PSE see TRIGger SEQuence SOURce on page 209 Baseband Power Trigger Source Trigger Source Settings Defines triggering on the baseband power for baseband input via the Digital Baseband Interface R amp S FSW B17 or the Analog Baseband interface R amp S FSW B7 1 For more information on the the Digital Baseband Interface or the Analog Baseband Interface see the R amp S FSW UO Analyzer and l Q Input User Manual Remote command TRIG SOUR BBP see TRIGger SEQuence SOURce on page 209 Digital I Q Trigger Source Trigger Source Settings For applications that process l Q data such as the UO Analyzer or optional applica tions and only if the Digital Baseband Interface R amp S FSW B17 is available Defines triggering of the measurement directly via the LVDS connector In the selection list you must specify which general purpose bit GPO to GP5 will provide the trigger data Note If the Digital UO enhanced mode is used i e the connected device supports transfer rates up to 200 Maps only the general pu
220. ed since the last PRESET operation These parameters can be changed but are not reset automatically the next time you re enter the measure ment Refer to the description of each measurement type for details The main measurement configuration menus for the WLAN frequency sweep measure ments are identical to the Spectrum application For details refer to Measurements in the R amp S FSW User Manual The measurement specific settings for the following measurements are available via the Overview e Channel Power ACLR Measurements A 147 Spectrum Emission Mask ec be a 148 Occupied Bandwidth EE 149 ee EE 150 5 4 1 Channel Power ACLR Measurements The Adjacent Channel Power measurement analyzes the power of the TX channel and the power of adjacent and alternate channels on the left and right side of the TX chan nel The number of TX channels and adjacent channels can be modified as well as the band class The bandwidth and power of the TX channel and the bandwidth spacing and power of the adjacent and alternate channels are displayed in the Result Sum mary 5 4 2 Frequency Sweep Measurements Channel Power ACLR measurements are performed as in the Spectrum application with the following predefined settings according to WLAN specifications adjacent channel leakage ratio Table 5 3 Predefined settings for WLAN ACLR Channel Power measurements Setting Default value ACLR Standard same as defined
221. ed measurements see the R amp S FSW User Manual TIMES SOURCES SUING EE 109 L VE 110 A O A 110 bs itera Tigger tee ici tradi tit 110 e MT 110 dci lnntdende 111 od Ts 111 A 111 L Power SA 112 L Baseband OWN sisi 112 O PEPPER 112 o Level Miesen tu acd ser oer 113 order anni iaa 113 ir e i A 113 Bro Sii METEO T T 113 ET Eno RETE E NM 113 do a un E 114 o ebe 114 Doo EE 114 LEE A UT 114 O 114 L Output A 115 A A M 115 L Pulse ET 115 Pgs PONE saint dest dou ein e EE 115 Trigger Source Settings The Trigger Source settings define when data is captured WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Trigger Source Trigger Source Settings Defines whether a trigger is to be considered at all and if so which signal IF RF external signal etc will provide the trigger signal 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 209 Free Run Trigger Source Trigger Source Settings 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 209 External Trigger 1 2 3 Trigger Source Trigger Source Settings Data acquisition starts when the TTL signal fed into the spec
222. ed value limit defined in standard Max Limit Maximum measured value limit defined in standard UO Offset An UO offset indicates a carrier offset with fixed amplitude This results in a constant shift of the UO axes The offset is normalized by the mean symbol power and displayed in dB 3 1 1 2 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance ON PERE EIA drehen t ll Fig 3 1 I Q offset in a vector diagram Gain Imbalance An ideal UO modulator amplifies the and Q signal path by exactly the same degree The imbalance corresponds to the difference in amplification of the and Q channel and therefore to the difference in amplitude of the signal components In the vector dia gram the length of the vector changes relative to the length of the Q vector The result is displayed in dB and where 1 dB offset corresponds to roughly 12 difference between the and Q gain according to the following equation Imbalance dB 20log Gaing Gain Positive values mean that the Q vector is amplified more than the vector by the corre sponding percentage For example using the figures mentioned above 0 98 20 log10 1 12 1 pum vaa ee Fig 3 2 Positive gain imbalance Negative values mean that the vector is amplified more than the Q vector by the cor responding percentage For example using the figures mentioned above 0 98 20 log10 1 1 12 3 1 1 3
223. ee the R amp S FSW Getting Started manual WLAN IQ Measurement Modulation Accuracy Flat ness Tolerance When you activate the WLAN application an UO measurement of the input signal is started automatically with the default configuration The WLAN menu is displayed and provides access to the most important configuration functions This menu is also displayed when you press the MEAS CONFIG key on the front panel The Span Bandwidth Lines and Marker Functions menus are not available for WLAN IQ measurements WLAN measurements can be configured easily in the Overview dialog box which is displayed when you select the Overview softkey from any menu e Default Settings for WLAN Measurement AAA 88 Configuration e 89 Signal Kleber oo ai ito 91 e Jla putamnd Fronterid SINS maana E 92 e Signal Capture Data Acquisition pi recie edis 107 e Synchronization and OFDM Demodulation eere nennen 121 e Tracking and Channel Eetmaton nenne 122 e DOMO DEE 124 E SE en Re EE 139 5 3 1 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance EI le TE E 142 Aoma SUID S e is aie on Can tocca ra id rec dte c no ad tunes 145 LER IE IIo Am 146 Default Settings for WLAN Measurements When you activate the WLAN application the first time a set of parameters is passed on from the currently active application e center frequency and frequency offset e reference level and reference
224. eese 270 CALOulate LIMit BURStEVM PILot AVERage RESUIt essen 270 CALCulate LIMit BURSt EVM PILotMAXimum RESUIE eiie eene en enano nnn nang 270 CALCulate LIMit BURSt FERRor AVERage RE Gut 270 CALOulate LIMit BURSt FERRor MAXimum RESUIt losses eese 270 CALCulate LIMit BURSt IQOFfset AVERage RESUIt eese 271 CALCulate LIMIEBURSEIQOFfsetMAXimu mt RESUll 5 241 eraot nani rn neni 271 CALOCulate LIMit BURSt SYMBolerror AVERage RESUIt sse 271 CALOulate LIMit BURSt SYMBolerror MAXimum RESUIt eese 271 CALCulate LIMit BURSt ALL RESult This command returns the result of the EVM limit check for all carriers The limit value is defined by the standard or the user see CALCulate LIMit BURSt ALL on page 239 Return values lt LimitCheck gt PASS The defined limit for the parameter was not exceeded FAILED The defined limit for the parameter was exceeded Usage Query only CALCulate LIMit BURSt EVM ALL AVERage RESult CALCulate LIMit BURSt EVM ALL MAXimum RESult This command returns the result of the average or maximum EVM limit check The limit value is defined by the standard or the user see CALCulate LIMit BURSt EVM ALL MAXimum on page 239 Retrieving Results Return values lt LimitCheck gt PASS The defined limit for the parameter was not exceeded FAILED The defined li
225. efine your own spatial mapping between streams and Tx antennas For each antenna Tx1 4 the complex element of each STS stream is defined The upper value is the real part part of the complex element The lower value is the imagi nary part of the complex element Additionally a Time Shift can be defined for cyclic delay diversity CSD The stream for each antenna is calculated as User Manual 1173 9357 02 11 69 Signal Processing for MIMO Measurements IEEE 802 11ac n Tx Stream Tx STS 1 Tx STSA STS Stream Tx Stream Tx STS l Tx STSA ASTS Stream 4 3 3 Physical vs Effective Channels The effective channel refers to the transmission path starting from the space time stream and ending at the receive antenna It is the product of the following compo nents e the spatial mapping e the crosstalk inside the device under test DUT transmission paths e the crosstalk of the channel between the transmit antennas and the receive anten nas For each space time stream at least one training field the V HT LTF is included in every PPDU preamble see figure 4 4 Each sender antenna transmits these training fields which are known by the receive antenna The effective channel can be calcula ted from the received and known V HT LTF symbols of the preamble without knowl edge of the spatial mapping matrix or the physical channel Thus the effective channel can always be calculated HT mixed
226. el gt Defines or queries the Full Scale Level i e the level that corresponds to an I Q sam ple with the magnitude 1 This command is only available if the optional Digital Baseband Interface R amp S FSW B17 is installed Parameters lt Level gt lt numeric value gt Range 1pV to 7 071 V RST 1V Manual operation See Full Scale Level on page 95 10 5 2 3 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance INPut DIQ RANGe UPPer UNIT lt Unit gt Defines the unit of the full scale level See Full Scale Level on page 95 The availa bility of units depends on the measurement application you are using This command is only available if the optional Digital Baseband Interface R amp S FSW B17 is installed Parameters lt Level gt VOLT DBM DBPW WATT DBMV DBUV DBUA AMPere RST Volt Manual operation See Full Scale Level on page 95 INPut DIQ SRATe lt SampleRate gt This command specifies or queries the sample rate of the input signal from the Digital Baseband Interface R amp S FSW B17 see Input Sample Rate on page 95 Parameters lt SampleRate gt Range 1 Hz to 10 GHz RST 32 MHz Example INP DIQ SRAT 200 MHz Manual operation See Input Sample Rate on page 95 INPut DIQ SRATe AUTO lt State gt If enabled the sample rate of the digital UO input signal is set automatically by the con nected device This command is only available if
227. ent in that channel is activated by the Sequencer Starting a Measurement Parameters lt State gt ON OFF 0 1 ON 1 Continuous sweep OFF 0 Single sweep RST 1 Example INIT CONT OFF Switches the sweep mode to single sweep INIT CONT ON Switches the sweep mode to continuous sweep Manual operation See Continuous Sweep RUN CONT on page 146 INITiate IMMediate This command starts a single new measurement You can synchronize to the end of the measurement with OPC OPC or WAI For details on synchronization see the Remote Basics chapter in the R amp S FSW User Manual Manual operation See Single Cont on page 120 See Single Sweep RUN SINGLE on page 146 INITiate 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 SEQuencer IMMediate on page 259 To deactivate the Sequencer use SYSTem SEQuencer on page 261 Usage Event Manual operation See Sequencer State on page 86 INITiate SEQuencer IMMediate This command starts a new sequence of measurements by the Sequencer Its effect is similar to the INITiate IMMediate command used for a single measurement Before this command can be executed the Sequencer must be activated see SYSTem SEQuencer on page 261 Starting a Measurement Example SYST SEQ ON Activates the Sequencer INIT SEQ MODE SING Set
228. ents chap ter Parameters lt 1 gt lt Filename gt Example Commands for Compatibility string Path and name of the xm1 file that contains the SEM setup information MMEM LOAD SEM STAT 1 Nsem StdNWLANN802 11a1802 11a 10MHz 5GHz band XML SENSe DEMod FORMat BANalyze BTYPe lt PPDUType gt This remote control command specifies the type of PPDU to be analyzed Only PPDUs of the specified type take part in measurement analysis Parameters lt PPDUType gt Manual operation LONG Only long PLCP PPDUs are analyzed Available for IEEE 802 11b g SHORT Only short PLCP PPDUs are analyzed Available for IEEE 802 11b g MM20 IEEE 802 11n Mixed Mode 20 MHz sampling rate Note that this setting is maintained for compatibility reasons only Use the specified commands for new remote control pro grams see SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 and SENSe BANDwidth CHANnel AUTO TYPE on page 225 For new programs use SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE MMIX SENSe BANDwidth CHANnel AUTO TYPE MB20 GFM20 IEEE 802 11n Green Field Mode 20 MHz sampling rate Note that this setting is maintained for compatibility reasons only Use the specified commands for new remote control pro grams see SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 and SENSe BANDwidth CHANnel AUTO TYPE on page 225 For new programs use SENSe
229. ents and Result Displays 3 2 2 Ref Level 0 50 dBm AnBW 40 MHz Att 9dB Meas Time 12 5 ms CF 100 0 MHz Mean Pwr 20 00 dB 2 Result Summary Samples 500000 Mean Peak Crest 1 0 1 Trace 1 7 22 dBm 3 34 dBm 10 56 dB B 0 0 o Fig 3 29 CCDF measurement results Remote command CONFigure BURSt STATistics CCDF IMMediate on page 183 Querying results CALCulate lt n gt MARKer lt m gt Y on page 290 CALCulate STATistics RESult lt t gt on page 275 Evaluation Methods for Frequency Sweep Measurements The evaluation methods for frequency sweep measurements in the R amp S FSW WLAN application are identical to those in the R amp S FSW base unit Spectrum application BICI 51 Rosul SUMMA EE 52 uin ME c nN Eea 52 Marker Peak bil ace elt tc ed ceni b edd dv ctr b t or 52 Diagram Displays a basic level vs frequency or level vs time diagram of the measured data to evaluate the results graphically This is the default evaluation method Which data is displayed in the diagram depends on the Trace settings Scaling for the y axis can be configured mm CEP MENU NC RNC AN NN NU User Manual 1173 9357 02 11 51 R amp S FSW K91 Measurements and Result Displays CF 1 95 GHz 1001 pts 2 57 MHz Span 25 7 MHz Remote command LAY ADD 1 RIGH DIAG see LAYout ADD WINDow on page 248 Result Summary Result summaries provide
230. ents in the WLAN Application on page 156 The basic procedure to perform each measurement and step by step instructions for more complex tasks or alternative methods e chapter 9 Optimizing and Troubleshooting the Measurement on page 164 Hints and tips on how to handle errors and optimize the test setup e chapter 10 Remote Commands for WLAN Measurements on page 167 Remote commands required to configure and perform WLAN 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 FSW User Manual Programming examples demonstrate the use of many commands and can usually be executed directly for test purposes e chapter A Annex Reference on page 307 Reference material e List of remote commands Alphahabetical list of all remote commands described in the manual e Index Documentation Overview 1 2 Documentation Overview The user documentation for the R amp S FSW consists of the following parts e Printed Getting Started manual e Online Help system on the instrument e 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 Help is embedded in the instrument s firmware It offers quick context sen sitive access to the complete information needed for operation and
231. enuation 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 Option B25 is not available mechanical attenuation is applied This function is not available for input from the Digital Baseband Interface R amp S FSW B17 In Manual mode you can set the RF attenuation in 1 dB steps down to 0 dB also using the rotary knob 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 reference level is adjusted accordingly and the warning Limit reached is displayed 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 200 INPut ATTenuation AUTO on page 200 Using Electronic Attenuation Option B25 If option R amp S FSW B25 is installed 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance This function is not avail
232. equired tolerance limit depends on the used standard Prior IEEE 802 11 2012 Standard Tolerance limits are based on the IEEE 802 11 specification prior to 2012 Default for OFDM standards except 802 11ac In line with IEEE 802 11 2012 Standard Tolerance limits are based on the IEEE 802 11 specification from 2012 Required for DSSS standards Also possible for OFDM standards except 802 11ac WLAN IQ Measurement Modulation Accuracy Flatness Tolerance In line with IEEE 802 11ac standard Tolerance limits are based on the IEEE 802 11ac specification Required by IEEE 802 11ac standard Remote command CALCulate LIMit TOLerance on page 185 5 3 4 Input and Frontend Settings The R amp S FSW can analyze signals from different input sources and provide various types of output such as noise or trigger signals Importing and Exporting UO Data The l Q data to be analyzed for WLAN 802 11 can not only be measured by the WLAN application itself it can also be imported to the application provided it has the correct format Furthermore the analyzed l Q data from the WLAN application can be expor ted for further analysis in external applications See chapter 7 1 Import Export Functions on page 152 Frequency amplitude and y axis scaling settings represent the frontend of the mea surement setup For more information on the use and effects of these settings see chapter 4 8 Pre paring the R amp S FSW for the
233. er in dB ALL Results of all three measurements mentioned before separated by commas lt mean power gt lt peak power gt lt crest factor gt Example CALC STAT RES2 ALL Reads out the three measurement results of trace 2 Example of answer string 5 56 19 25 13 69 i e mean power 5 56 dBm peak power 19 25 dBm crest factor 13 69 dB Usage Query only Manual operation See CCDF on page 50 Retrieving Results 10 9 3 Retrieving Trace Results The following commands describe how to retrieve the trace data from the WLAN IQ measurement Modulation Accuracy Flatness and Tolerance Note that for these measurements only 1 trace per window can be configured The traces for frequency sweep measurements are identical to those in the Spectrum application Useful commands for retrieving results described elsewhere e DISPlay WINDow lt n gt SELect on page 182 Remote commands exclusive to retrieving trace results POR EE 276 SENSE ET 277 SENSE BURSESELCCESTA TO ocio 277 o EE 277 TRACE DATA E 279 TRACeIO DATA MEMO EE 279 FORMat DATA lt Format gt This command selects the data format that is used for transmission of trace data from the R S FSW to the controlling computer Note that the command has no effect for data that you send to the R amp S FSW The R amp S FSW automatically recognizes the data it receives regardless of the format Parameters lt Format gt ASCii ASCii format separated by commas
234. er since only one connector is occupied by a probe the Single ended setting must be used for all probes Differential Q and inverse I Q data Single Ended l Q data only Remote command INPut IQ BALanced STATe on page 192 Center Frequency Defines the center frequency for analog baseband input For real type baseband input I or Q only the center frequency is always 0 Hz Note If the analysis bandwidth to either side of the defined center frequency exceeds the minimum frequency 0 Hz or the maximum frequency 40 MHz 80 MHz an error is displayed In this case adjust the center frequency or the analysis bandwidth Remote command SENSe FREQuency CENTer on page 196 5 3 4 2 Output Settings The R amp S FSW can provide output to special connectors for other devices For details on connectors refer to the R amp S FSW Getting Started manual Front Rear Panel View chapters WLAN IQ Measurement Modulation Accuracy Flatness Tolerance O How to provide trigger signals as output is described in detail in the R amp S FSW User Manual 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 Noise Source Trigger 2 Trigger 3 e 99 O 99 Mies c E 100 A O 100 L RTE 100 L Send O Eet 100 Noise Source Switches the supply voltage for an external noise source on or off External nois
235. eric value in dB The unit for the EVM parameters can be changed in advance using UNIT EVM on page 268 Default unit DB CALCulate LIMit BURSt EVM PILot AVERage Limit CALCulate LIMit BURSt EVM PILot MAXimum Limit This command sets or queries the maximum error vector magnitude limit for the pilot carriers determined by the default WLAN measurement For details on the EVM results and the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Parameters Limit numeric value in dB The unit for the EVM parameters can be changed in advance using UNIT EVM on page 268 Default unit DB CALCulate LIMit BURSt FERRor AVERage Limit CALCulate LIMit BURSt FERRor MAXimum Limit This command sets or queries the average or maximum center frequency error limit determined by the default WLAN measurement For details on the center frequency error results and the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Limit gt numeric value in Hertz Default unit HZ CALCulate LIMit BURSt IQOFfset AVERage Limit CALCulate LIMit BURSt IQOFfset MAXimum Limit This command sets or queries the average or maximum UO offset error limit deter mined by the default WLAN measurement For deta
236. erload EE 78 Overload remote 186 RE arne Na a T les 93 Settings uz 92 106 Signal eu CEET 78 Source Configuration softkey ssss 92 Source Analog Baseband Source connection errors Source digital WO E Source Radio frequency RE 93 Input sample rate 32 107 Default erc ette e Es 88 NIE p P 11 REMOTE esee TE 204 Input sample rate ISR Definito Msa ceo orta eine Etre sh dan ees 307 Digital Q EE 95 Installation ets i9 Inter channel interference ICI sssss 56 IP address OSP switchbox MIMO ote es 119 J Joined RX Sync and Tracking MIMO e 118 K Keys i M est 87 UNES essex EE 87 MKR FUNCT ccscuscescccesscssosessencenseacdessensesacndesevaudarsscsenecs 87 RUIN Kee 1 ME 146 RUN SINGLE 1 Serge Eeer ot eoru ex preme 146 SPAN e 87 L Level leie daro Tracking IEEE 802 11a g OFDM Level etror tracking citer tent Limits Defining remote cn emere tr er 238 EVM iiit 239 240 EVM pilot carriers result rae 270 EVM result 269 270 Fredgeuncy error result drei i eco 270 FTeQUENCy SMON vivir 240 OS OSE MR n 241 VQ offset result voca tati 271 Symbol clock erTOF corona tenet t 241 Symbol clock error Feelt vec ccedv Genie 271 Lines M n ec 87 Literature
237. es The term select may refer to any of the described methods i e using a finger on the touchscreen a mouse pointer in the display or a key on the instrument or on a key board Starting the WLAN Application 2 Welcome to the WLAN Application The R amp S FSW WLAN application extends the functionality of the R amp S FSW to enable accurate and reproducible Tx measurements of a WLAN device under test DUT in accordance with the standards specified for the device The following standards are currently supported if the corresponding firmware option is installed e EEE standards 802 11a e EEE standards 802 11ac SISO MIMO e EEE standards 802 11b e IEEE standards 802 11g OFDM e EEE standards 802 11g DSSS e EEE standards 802 11n SISO MIMO e EEE standards 802 11p The R amp S FSW WLAN application features Modulation measurements e Constellation diagram for demodulated signal e Constellation diagram for individual carriers e Q offset and UO imbalance e Modulation error EVM for individual carriers or symbols e Amplitude response and group delay distortion spectrum flatness Further measurements and results e Amplitude statistics CCDF and crest factor e FFT also over a selected part of the signal e g preamble e Payload bit information This user manual contains a description of the functionality that is specific to the appli cation including remote control operation All functions not discusse
238. es are supported depends on the selected digital standard some are also interdependant Table 4 1 Supported modulation formats PPDU formats and channel bandwidths depending on standard Standard Modulation formats PPDU formats Channel bandwidths IEEE 802 11a g OFDM p BPSK 6 Mbps amp 9 Mbps QPSK 12 Mbps amp 18 Mbps 16QAM 24 Mbps amp 36 Mbps 64QAM 48 Mbps amp 54 Mbps Non HT Short PPDU Long PPDU 5 MHz 10 MHz 20 MHz IEEE 802 11ac 16QAM 64QAM 256QAM 1024QAM VHT 20 MHz 40 MHz 80 MHz 160 MHz IEEE 802 11b g DSSS DBPSK 1 Mbps DQPSK 2 Mbps CCK 5 5 Mbps amp 11 Mbps PBCC 5 5 Mbps amp 11 Mbps Short PPDU Long PPDU 22 MHz IEEE 802 11n SISO BPSK 6 5 7 2 13 5 amp 15 Mbps QPSK 13 14 4 19 5 21 7 27 30 40 5 amp 45 Mbps 16QAM 26 28 9 39 43 3 54 60 81 amp 90 Mbps 64QAM 52 57 8 58 5 65 72 2 108 121 5 135 120 135 amp 150 Mbps MIMO depends on the MCS index HT MF Mixed format HT GF Greenfield format 20 MHZ 40 MHz requires R amp S FSW bandwidth extension option see chapter A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input on page 307 R amp S FSW K91 4 7 4 7 1 4 7 2 4 7 3 Measurement Basics Receiving Data Input and Providing Data Output The R amp S FSW can analyze signals from different input sources a
239. esncdeiidanesnscesauanctectaaubedses snes as 263 PE VCS TI MBOLCOUNGE atada tea edes estet dte aor ido 263 usb Bc y EEUU 263 EMC BUR NR eiie ettet an 263 UNM BURSI m 263 FETCh BURSt COUNt This command returns the number of analyzed PPDUs from the current capture buffer If multiple measurements are required because the number of PPDUS to analyze is greater than the number of PPDUs that can be captured in one buffer this command only returns the number of captured PPDUS in the current capture buffer as opposed to FETCh BURSt COUNt ALL Usage Query only Retrieving Results FETCh BURSt COUNt ALL This command returns the number of analyzed PPDUs for the entire measurement If multiple measurements are required because the number of PPDUs to analyze is greater than the number of PPDUs that can be captured in one buffer this command returns the number of analyzed PPDUs in all measurements as opposed to FETCh BURSt COUNt Usage Query only FETCh SYMBol COUNt This command returns the number of symbols in each analyzed PPDU as a comma separated list The length of the list corresponds to the number of PPDUs i e the result of FETCh BURSt COUNTE ALL Usage Query only FETCh BURSt LENGths This command returns the length of the analyzed PPDUs from the current measure ment If the number of PPDUs to analyze is greater than
240. eviewing the I Q data in a web browser The ig tar file format allows you to preview the I Q data in a web browser 1 Use an archive tool e g WinZip or PowerArchiver to unpack the iq tar file into a folder 2 Locate the folder using Windows Explorer 3 Open your web browser gt xzy xml How to Export and Import UO Data 4 Drag the l Q parameter XML file e g example xm1 into your web browser al gt file D fy xml e D x xzy xml xzy xml of iq tar file Saved by FSV IQ 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 xzy complex 1ch float32 Scaling factor 1v 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 schwarz com Internet http Avww rohde schwarz com Fileformat version 1 How to Determine Modulation Accuracy Flatness and Tolerance Parameters for WLAN Signals 8 How to Perform Measurements in the WLAN Application The following step by step instructions demonstrate how to perform measurements in the R amp S FSW WLAN application The following tasks are described e How to Determin
241. f analyzed PPDUs as defined by the Evaluation Range gt Statistics settings see PPDU Statistic Count No of PPDUs to Analyze on page 140 All 57 carriers are shown including the unused carrier 0 This result display is not available for single carrier measurements IEEE 802 11b g DSSS FGroup Delay Carrier 250 50 1 Carrier Carrier 250 CEA AAA User Manual 1173 9357 02 11 33 R amp S FSW K91 Measurements and Result Displays 3 Group Delay Stream 4 RX1T 4 Stream 1 Rx 1 4 Stream 2 Rx 1 4 Stream 3 Rx 1 4 Stream 4 Rx1 4 St 3 1 Stream 1 Rx 1 3 2 Stream 1 Rx 2 3 3 Stream 1 Rx 3 3 4 Stream 1 Rx 4 Carrier 25 Carr CE Carrier 25 r Carrie Carrier 25 Carr Carrier 25 Carr 3 5 Stream 2 Rx 1 3 6 Stream 2 2 3 7 Stream 2 Rx 3 3 8 Stream 2 Rx 4 Carrier 25 Carr Carrier 25 Carr arrie Carrier 25 Carr arrier Carrier 25 Carr 3 9 Stream 3 Rx 1 3 10 Stream 3 Rx 2 3 11 Stream 3 Rx 3 3 12 Stream 3 Rx 4 Carrier 25 Carr d Carrier 25 Carr Carrie Carrier 25 Carr C Carrier 25 Carr Ce 3 13 Stream 4 Rx 1 3 14 Stream 4 Rx 2 3 15 Stream 4 Rx 3 3 16 Stream 4 Rx 4 Fig 3 15 Group delay result display for IEEE 802 11n MIMO measurements Group delay is a measure of phase distortion and defined as the derivation of phase over frequency To calculate the group delay the estimated channel is upsampled inactive carriers are interpolated and phases are unwrapped before they are differentiated over the carrier frequencies T
242. f 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 10 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 Example LAY SPL 1 4 70 Moves the splitter between window 1 Frequency Sweep and 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 LAY out WINDow lt n gt ADD lt Direction gt lt WindowType gt This command adds a measurement window to the display Note that with this com mand the suffix lt n gt determines the existing window next to which the new window is added as opposed to LAYout ADD WINDow for which the existing window is defined by a parameter To replace an existing window use the LAYout WINDo
243. ffset in the I branch and the IQ offset of the Q branch are estimated sepa rately ge y REAL O UO offset l branch 4 16 S 1 AN o Sch IMAG v N v 0 UO offset Q branch 4 17 where r v is the measurement signal which has been corrected with the estimates of the timing offset frequency offset and phase offset but not with the estimates of the gain imbalance and UO offset With these values the gain imbalance of the I branch and the gain imbalance of the Q branch are estimated in a non linear estimation in a second step i 18 amp LS rEaLE0 v 0 Gain imbalance l branch 4 18 1Y S y IMAG tt 60 Gain imbalance Q branch 4 19 Finally the mean error vector magnitude can be calculated with a non data aided cal culation TE SC q NA 8 22 REAL v 0 g uc IMAG v 02 90 0 v 0 Verr v Zk al Mean error vector magnitude 4 20 The symbol error vector magnitude is the error signal magnitude normalized by the root mean square value of the estimate of the measurement signal power R amp S FSW K91 O 4 2 3 4 3 CEA AAA User Manual 1173 9357 02 11 67 Measurement Basics i REAL v 6 9 IMAG r v a do pera Symbol error vector magnitude 4 21 Verr v The advantage of this method is that no estimate of the reference signal is needed but the UO offset and gain imbalance values are not estimated in a
244. for the parameter was exceeded 10 9 2 Retrieving Results Usage Query only CALCulate LIMit BURSt IQOFfset AVERage RESult CALCulate LIMit BURSt IQOFfset MAXimum RESult This command returns the result of the average or maximum UO offset limit check The limit value is defined by the standard or the user see CALCulate LIMit BURSt IQOFfset MAXimum on page 241 Return values lt LimitCheck gt PASS The defined limit for the parameter was not exceeded FAILED The defined limit for the parameter was exceeded Usage Query only CALCulate LIMit BURSt SYMBolerror AVERage RESult CALCulate LIMit BURSt SYMBolerror MAXimum RESult This command returns the result of the average or maximum symbol clock error limit check The limit value is defined by the standard or the user See CALCulate LIMit BURSt SYMBolerror MAXimum on page 241 Return values lt LimitCheck gt PASS The defined limit for the parameter was not exceeded FAILED The defined limit for the parameter was exceeded Usage Query only Numeric Results for Frequency Sweep Measurements The following commands are required to retrieve the numeric results of the WLAN fre quency sweep measurements see chapter 3 2 Frequency Sweep Measurements on page 47 In the following commands used to retrieve the numeric results for RF data the suf fixes n for CALCulate and lt k gt for LIMit are irrelevant CAL Culate LIMit ACPower ACHannel HREGu
245. format PPDU 1 4 Data HT LTFs Extension HT LTFs Kb lt gt 3 3 8 8 8 8 8 8 8 Eu EA Sa ES ga Sg gag 4 ES Go Ge at Ge at at Oot e t p N e N Kg a e HT greenfield format PPDU 1 3 Data HT LTFs Extension HT LTFs Fig 4 4 Training fields TF in the preamble of PPDUs in IEEE 802 11n standard The effective channel is sufficient to calculate the EVM the constellation diagram and the bitstream results of the measured signal so these results are always available The physical channel refers to the transmission path starting from the transmit antenna streams and ending at the receive antenna It is the product of the following components e the crosstalk inside the device under test DUT transmission paths e the crosstalk of the channel between the transmit antennas and the receive anten nas R amp S FSW K91 Measurement Basics The physical channel is derived from the effective channel using the inverted spatial mapping matrix Q Hohy Ha Thus if the spatial mapping matrix cannot be inverted the physical channel cannot be calculated This may be the case for example if the signal contains fewer streams than Rx antenna signals or if the spatial matrix is close to numerical singularity In this case results that are based on the transmit antenna such as UO offset gain imbalance and quadrature offset are not available Crosstalk in estimated channels E Note that the estimated channel transfer function contains
246. from the FFT This is an exhaustive call due to the fact that there are nearly always more FFT points than UO samples The number of FFT points is a power of 2 that is higher than the total number of UO samples i e number of FFT points round number of I Q samples to next power of 2 E g if there were 20000 samples then 32768 FFT points are returned Data is returned in floating point format in dBm Group Delay Currently the following trace types are provided with this measurement e TRACEL A repeating list of group delay values for each subcarrier The number of repeating lists corresponds to the number of fully analyzed PPDUs as displayed in the cur rent Magnitude Capture Each group delay value is returned as a floating point number expressed in units of seconds e TRACE All group delay values per subcarrier for each analyzed PPDU of the capture period Example For GDmn the group delay of the m th analyzed PPDU for the subcarrier correspond ing to n 1 2 Nusea TRACE DATA TRACE2 Analyzed PPDU 1 GD GD 2 SEN Analyzed PPDU 2 GD GD gt 3 Analyzed PPDU N GDy 1 GDy is Power vs Time Full Burst and Rising Falling Data All complete PPDUs within the capture time are analyzed in three master PPDUs The three master PPDUs relate to the minimum maximum and average values across all complete PPDUs This data is returned in dBm values on a per sample basis Each sample rela
247. ftkey is highlighted blue During an active Sequencer process the selected mode softkey is highlighted orange Single Sequence Each measurement is performed once until all measurements in all active channels have been performed Continuous Sequence The measurements in each active channel are performed one after the other repeatedly in the same order until sequential operation is stopped This is the default Sequencer mode Remote command INITiate SEQuencer MODE on page 260 5 2 5 3 Display Configuration Display Configuration The measurement results can be displayed using various evaluation methods All eval uation methods available for the R amp S FSW WLAN application are displayed in the evaluation bar in SmartGrid mode when you do one of the following e Select the EJ SmartGrid icon from the toolbar e Select the Display Config button in the Overview e Select the Display Config softkey in any WLAN menu Then you can drag one or more evaluations to the display area and configure the lay out as required Up to 16 evaluation methods can be displayed simultaneously in separate windows The WLAN evaluation methods are described in chapter 3 Measurements and Result Displays on page 13 To close the SmartGrid mode and restore the previous softkey menu select the 2 Close icon in the righthand corner of the toolbar or press any key on the front panel For details on working with the SmartGrid s
248. g DSSS 3 AM EVM 10 0 dBm Remote command LAY ADD 1 RIGH AMEV see LAYout ADD WINDow on page 248 or CONFigure BURSt AM EVM IMMediate on page 178 IESSE User Manual 1173 9357 02 11 24 R amp S FSW K91 Measurements and Result Displays EH Bitstream This result display shows and demodulated payload data stream for all analyzed PPDUs of the currently captured UO data as indicated in the Magnitude Capture dis play The bitstream is derived from the constellation diagram points using the constel lation bit encoding from the corresponding WLAN standard See for example IEEE Std 802 11 2012 Fig 18 10 BPSK QPSK 16 QAM and 64 QAM constellation bit encoding Thus the bitstream is NOT channel decoded For multicarrier measurements IEEE 802 11a g OFDM ac n p the results are grouped by symbol and carrier 1 Bitstream Carrier Symbol 1 26 000010 110111 111110 23 000001 010100 0 20 011001 101010 010101 17 001010 011100 101010 14 111100 001010 001101 011011 111110 010010 111100 0 001100 001101 111100 101100 101010 100011 NULL 101010 101101 101010 011010 000101 010001 0 101101 001011 10 000110 100100 100101 13 101001 111101 101011 16 011100 111001 010010 19 110100 111001 0 22 000011 101111 101111 25 001111 111100 Carrier Symbol 2 Fig 3 7 Bitstream result display for IEEE 802 11a y OFDM ac n p standards For MIMO measurements IEEE 802 11ac n the results are groupe
249. g concept of the WLAN 802 11 application for IEEE 802 11b or g DSSS signals Abbreviations E timing offset nf frequency offset AQ phase offset 9 estimate of the gain factor in the Lbranch 9o estimate of the gain factor in the Q branch Ada accurate estimate of the crosstalk factor of the Q branch in the Lbranch h v estimated baseband filter of the transmit antenna Div estimated baseband filter of the receive antenna 6 estimate of the IQ offset in the I branch 6a estimate of the IQ offset in the I branch r v measurement signal v estimate of the reference signal 4 2 1 Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS v estimate of the power normalized and undisturbed reference signal ARG calculation of the angle of a complex value EVM error vector magnitude IMAG calculation of the imaginary part of a complex value PPDU protocol data unit a burst in the signal containing transmission data PSDU protocol service data unit a burst in the signal containing service data REAL calculation of the real part of a complex value e Block Diagram for Single Carrier Measurements sss 62 Caleulation of Signal Parameters coast EES 64 Literature on the IEEE 802 11b Standard ener ana 67 Block Diagram for Single Carrier Measurements A block diagram of the measurement applicatio
250. gle carrier measurements IEEE 802 11b g DSSS 4 AM AM Polynomial Fitting X 0 00 0 9 10 0 dBm Remote command LAY ADD 1 RIGH AMAM see LAYout ADD WINDow on page 248 or CONFigure BURSt AM AM IMMediate on page 178 Polynomial degree CONFigure BURSt AM AM POLYnomial on page 256 AM PM This result display shows the measured and the reference signal in the time domain For each sample the x axis value represents the amplitude of the reference signal The y axis value represents the angle difference of the measured signal minus the ref erence signal This result display is not available for single carrier measurements IEEE 802 11b g DSSS User Manual 1173 9357 02 11 23 R amp S FSW K91 Measurements and Result Displays See SSS eS SSS SSS SS SS SS ESS SSS SS 1 AM PM 1 Clrw 10 0 dBm Remote command LAY ADD 1 RIGH AMPM See LAYout ADD WINDow on page 248 or CONFigure BURSt AM PM IMMediate on page 178 AM EVM This result display shows the measured and the reference signal in the time domain For each sample the x axis value represents the amplitude of the reference signal The y axis value represents the length of the error vector between the measured signal and the reference signal The length of the error vector is normalised with the power of the corresponding refer ence signal sample This result display is not available for single carrier measurements IEEE 802 11b
251. gt FREQuency Displays frequency error results for the preamble of the mea sured PPDUs only PHASe Displays phase error results for the preamble of the measured PPDUs only Example CONF BURS PRE SEL PHAS Manual operation See Freq Error vs Preamble on page 32 See Phase Error vs Preamble on page 35 CONFigure BURSt PVT IMMediate This remote control command configures the measurement type to be Power vs Time Manual operation See PvT Full PPDU on page 37 See PvT Rising Edge on page 38 See PvT Falling Edge on page 39 CONFigure BURSt PVT SELect Mode This remote command determines how to interpret the Power vs Time measurement results Selecting a Measurement Parameters lt Mode gt EDGE Displays rising and falling edges only FALL Displays falling edge only FULL Displays the full PPDU RISE Displays the rising edge only Example CONF BURS PVT SEL FULL Interprets the measurement results as full PPDU Manual operation See PvT Full PPDU on page 37 See PvT Rising Edge on page 38 See PvT Falling Edge on page 39 CONFigure BURSt SPECtrum FFT IMMediate This remote control command configures the result display type of window 2 to be FFT Spectrum Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See FFT Spectrum on page 31 CONFigure BURSt SPECtrum FLATness SELect lt MeasType gt This remote
252. h the inverted channel matrix that is the mapping between the streams and the transmit antennas see chapter 4 3 2 Spa tial Mapping on page 69 Using space division multiplexing the transmitted data rates can be increased signifi cantly by using additional antennas To reduce the correlation between the propagation paths the transmit antenna can delay all of the transmission signals except one This method is referred to as cyclic delay diversity or cyclic delay shift The basis of the majority of the applications for broadband transmission is the OFDM method In contrast to single carrier methods an OFDM signal is a combination of many orthogonal separately modulated carriers Since the data is transmitted in paral lel the symbol length is significantly smaller than in single carrier methods with identi cal transmission rates Signal processing chain In a test setup with multiple antennas the R amp S FSW is likely to receive multiple spatial streams one from each antenna Each stream has gone through a variety of transfor mations during transmission The signal processing chain is displayed in figure 4 3 starting with the creation of the spatial streams in the transmitting device through the wireless transmission and ending with the merging of the spatial streams in the receiv ing device This processing chain has been defined by IEEE The following figure shows the basic processing steps performed by the transmit antenn
253. he Demod button to provide information on the modulated signal and how the PPDUS detected in the capture buffer are to be demodulated How to Analyze WLAN Signals in a MIMO Measurement Setup 10 Select the Evaluation Range button to define which data in the capture buffer you want to analyze 11 Select the Display Config button and select the displays that are of interest to you up to 16 Arrange them on the display to suit your preferences 12 Exit the SmartGrid mode 13 Start a new sweep with the defined settings e To perform a single sweep measurement press the RUN SINGLE hardkey e To perform a continuous sweep measurement press the RUN CONT hardkey Measurement results are updated once the measurement has completed 8 2 How to Analyze WLAN Signals in a MIMO Measure ment Setup MIMO measurements are only available for IEEE 802 11ac n standards They can be performed automatically or manually see chapter 4 3 4 Capturing Data from MIMO Antennas on page 71 To perform a manual sequential measurement 1 Press the MODE key on the front panel of the R amp S FSW 2 Select the WLAN item E Lo WLAN The R amp S FSW opens a new measurement channel for the WLAN application 3 Select the Overview softkey to display the Overview for a WLAN measurement 4 Select the Signal Description button to select the digital standard EEE 802 11ac or IEEE 802 11n 5 Select the Input Frontend button and then the
254. he communicating devices are using different formats of PPDUs are availa ble Thus you can restrict analysis to the supported formats Note The PPDU format determines the available channel bandwidths For details on supported PPDU formats and channel bandwidths depending on the standard see table 4 1 Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display Format column see Signal Field on page 43 Auto same type as first PPDU A1st The format of the first valid PPDU is detected and subsequent PPDUS are analyzed only if they have the same format Auto individually for each PPDU AI All PPDUs are analyzed regardless of their format Meas only M Only PPDUs with the specified format are analyzed Demod all as D All PPDUs are assumed to have the specified PPDU format Remote command SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 SENSe DEMod FORMat BANalyze on page 227 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Channel Bandwidth to measure CBW Defines the channel bandwidth of the PPDUS taking part in the analysis Depending on which standards the communicating devices are using different PPDU formats and channel bandwidths are supported For details on supported PPDU formats and channel bandwidths depending on the standard see table 4 1 Note The terms in brackets in the follow
255. he first intermediate fre quency The input signal must be in the frequency range between 500 MHz and 8 GHz The resulting trigger level at the RF input depends on the RF attenuation and preampli fication For details on available trigger levels see the data sheet Note If the input signal contains frequencies outside of this range e g for fullspan measurements the sweep may be aborted and a message indicating the allowed input frequencies is displayed in the status bar A Trigger Offset Trigger Polarity and Trigger Holdoff to improve the trigger stabil ity can be defined for the RF trigger but no Hysteresis This trigger source is not available for input from the Digital Baseband Interface R amp S FSW B17 or the Analog Baseband Interface R amp S FSW B71 If the trigger source RF Power is selected and digital UO or analog baseband input is activated the trigger source is automatically switched to Free Run Remote command TRIG SOUR RFP see TRIGger SEQuence SOURce on page 209 Time Trigger Source Trigger Source Settings Triggers in a specified repetition interval Remote command TRIG SOUR TIME see TRIGger SEQuence SOURce on page 209 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Power Sensor Trigger Source Trigger Source Settings Uses an external power sensor as a trigger source This option is only available if a power sensor is connected and configur
256. he pilot carriers are inserted directly after the data carriers went through the STBC see also chapter 4 3 1 Space Time Block Coding STBC on page 69 Thus only the data carriers need to be decoded by the analyzer to determine characteristics of the demodulated data Because of this approach to calculate the EVM Constellation and Bitstream results you might get results for a different number of streams for pilots and data carriers if STBC is applied 4 3 6 4 4 Crosstalk and Spectrum Flatness In contrast to the SISO measurements in previous Rohde amp Schwarz signal and spec trum analyzers the spectrum flatness trace is no longer normalized to 0 dB scaled by the mean gain of all carriers For MIMO there may be different gains in the transmission paths and you do not want to lose the relation between these transmission paths For example in a MIMO trans mission path matrix we have paths carrying power usually the diagonal elements for the transmitted streams but also elements with only residual crosstalk power The power distribution of the transmission matrix depends on the spatial mapping of the transmitted streams But even if all matrix elements carry power the gains may be dif ferent This is the reason why the traces are no longer scaled to 0 dB Although the absolute gain of the Spectrum Flatness is not of interrest it is now maintained in order to show the different gains in the transmission matrix elements Nevert
257. he probe is reset to 0 0 V Suffix lt ch gt 1 4 Selects the input channel Parameters lt CMOffset gt Range 100E 24 to 100E 24 Increment 1E 3 RST 0 Default unit V TRACe IQ APCon STATe State If enabled the average power consumption is calculated at the end of the l Q data measurement This command must be set before the measurement is performed The conversion factors A and B for the calculation are defined using TRACe 10 APCon A and TRACe IQ APCon B The results can be queried using TRACe 10 APCon RESult on page 195 Parameters lt State gt ON OFF RST OFF Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Example RST O STAT ON Q SRAT 1MHZ TRAC IQ RLEN 1000000 Q APC STAT ON Q APC A 3 0 TRAC IQ APC B 0 6 INIT WAI TRAC IQ APC RES TRACe IQ APCon A lt ConvFact gt Defines the conversion factor A for the calculation of the average power consumption Parameters ConvFact numeric value RST 1 0 TRACe IQ APCon B lt ConvFact gt Defines the conversion factor B for the calculation of the average power consumption Parameters ConvFact numeric value RST 0 0 TRACe lQ APCon RESult Queries the average power consumption for an analog baseband input This value is only calculated at the end of the UO data measurement if the TRACe 10 APCon STATe command is set to ON before the measurement is performed P
258. he signal symbol field i e the PLCP header field of the first recog nized PPDU is analyzed to determine the details of the PPDU All PPDUS identical to the first recognized PPDU are analyzed All subsequent settings are set to Auto mode Auto individually for each PPDU All PPDUs are analyzed User defined User defined settings define which PPDUS are analyzed This setting is automatically selected when any of the subsequent settings are changed to a value other than Auto Remote command SENSe DEMod FORMat BCONtent AUTO on page 230 PPDU Format to measure Defines which PPDU formats are to be included in the analysis Depending on which standards the communicating devices are using different formats of PPDUs are availa ble Thus you can restrict analysis to the supported formats Note The PPDU format determines the available channel bandwidths For details on supported PPDU formats and channel bandwidths depending on the standard see table 4 1 Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display Format column see Signal Field on page 43 Auto same type as first PPDU A1st The format of the first valid PPDU is detected and subsequent PPDUs are analyzed only if they have the same format Auto individually for each PPDU AI All PPDUs are analyzed regardless of their format Meas only M Only PPDUs with the sp
259. he total transmitted power is not increased the measured powers can be normalised to consider this effect in demodulation 12 Select the Evaluation Range button to define which data in the capture buffer you want to analyze 13 Select the Display Config button and select the displays that are of interest to you up to 16 Arrange them on the display to suit your preferences 14 Exit the SmartGrid mode 15 Start the measurement via the OSP switch box The data is captured from all antennas automatically The data is evaluated and the result displays are updated for the individual data streams when the measurement is stopped To perform a simultaneous measurement with multiple R amp S FSWs and an R amp S FS Z11 Trigger Unit This measurement setup requires as many R amp S FSWs as Tx antennas are used They must all be connected via LAN Select one R amp S FSW as a master It is assumed the R amp S FS Z11 Trigger Unit is set up according to the following illustration DUT MASTER ANALYZER RF INPUT NOISE SOURCE RF OUTPUT 1 TRIGGER INPUT RF OUTPUT 2 RF OUTPUT 3 SLAVE ANALYZER 1 RF OUTPUT 4 RF INPUT TRIGGER OUTPUT TRIGGER INPUT SLAVE ANALYZER 2 RF INPUT TRIG INPUT TRIG OUT1 TRIGGER INPUT TRIG OUT2 gt gt TRIG Manual SLAVE ANALYZER 3 TRIG OUT3 RF INPUT NOISE SOURCE TRIG OUT4 TRIGGER INPUT Cable Trigger Cable Trigger optional DUT with TRIGGER OUTPUT Cable RF Fig 8 1 R amp S F
260. heless the limit lines are still symmetric to the mean trace individually for each element of the trans mission matrix Channels and Carriers In an OFDM system such as WLAN the channel is divided into carriers using FFT IFFT Depending on the channel bandwidth the FFT window varies between 64 and 512 see also chapter 4 6 Demodulation Parameters Logical Filters on page 77 Some of these carriers can be used active carriers others are inactive e g guard Recognized vs Analyzed PPDUs carriers at the edges The channel can then be determined using the active carriers as known points inactive carriers are interpolated 4 5 Recognized vs Analyzed PPDUs A PPDU in a WLAN signal consists of the following parts For IEEE 802 11n see also figure 4 4 e Preamble Information required to recognize the PPDU within the signal for example training fields e Signal Field Information on the modulation used for transmission of the useful data e Payload The useful data During signal processing PPDUs are recognized by their preamble symbols The rec ognized PPDUs and the information on the modulation used for transmission of the useful data are shown in the Signal Field result display see Signal Field on page 43 Not all of the recognized PPDUs are analyzed Some are dismissed because the PPDU parameters do not match the user defined demodulation settings which act as a logical filter see also chapter 4 6 Demodula
261. hile the connection between analyzer and digital UO data signal source e g R amp S SMU R amp S Ex 1 Q Box is established 10 Digital UO Output Connection Protocol error This bit is set if an error occurred while the connection between analyzer and digital UO data signal source e g R amp S SMU R amp S Ex 1 Q Box is established 11 Digital UO Output FIFO Overload This bit is set if an overload of the Digital UO Output FIFO occurred This happens if the output data rate is higher than the maximal data rate of the connected instrument Reduce the sample rate to solve the problem 12 14 not used 15 This bit is always set to 0 STATus QUEStionable DIG CONDIION 42 2 taa caida sonne ra os c ENEE 295 STATus QUEStionable DIQ ENABle eene nnne nn rn nnns nnne nnn nnn 296 STATUus QUEStIonable DIG IN Ee 296 STATUSGQUESIIDIYable DIG TP TISAISITIO DEE 296 STATUS QUESionable DIGI EVE E 297 STATus QUEStionable DIQ CONDition lt ChannelName gt This command reads out the CONDition section of the STATus QUEStionable DIQ CONDition status register The command does not delete the contents of the EVENt section Status Registers 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 Example STAT QUES DIQ COND Usage Query only STATus QUEStionable DIQ ENABle
262. hronous commands A command which does not automatically finish executing before the next com mand starts executing overlapping command is indicated as an Asynchronous command e Reset values RST Default parameter values that are used directly after resetting the instrument RST command are indicated as RST values if available e Default unit This is the unit used for numeric values if no other unit is provided with the parame ter e Manual operation If the result of a remote command can also be achieved in manual operation a link to the description is inserted 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 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 gt next to the keyword 10 2 4 10 2 5 10 2 6 Introduction If you don t quote a suffix for keywords that support one a 1 is assumed
263. hus the group delay indicates the time a pulse in the channel is delayed for each carrier frequency However not the absolute delay is of interest but rather the deviation between carriers Thus the mean delay over all carriers is deducted For an ideal channel the phase increases linearly which causes a constant time delay over all carriers In this case a horizontal line at the zero value would be the result The numeric trace results for this evaluation method are described in chap ter 10 9 4 11 Group Delay on page 287 Remote command LAY ADD 1 RIGH GDEL see LAYout ADD WINDow on page 248 or CONF BURS SPEC FLAT SEL GRD see CONFigure BURSt SPECtrum FLATness SELect on page 181 and CONFigure BURSt SPECtrum FLATness IMMediate on page 182 T Magnitude Capture The Magnitude Capture Buffer display shows the complete range of captured data for the last sweep Green bars at the bottom of the Magnitude Capture Buffer display indi cate the positions of the analyzed PPDUs User Manual 1173 9357 02 11 34 R amp S FSW K91 Measurements and Result Displays 1 Magnitude Capture Note MIMO measurements When you capture more than one data stream MIMO measurement setup see chapter 4 3 Signal Processing for MIMO Measurements IEEE 802 11ac n on page 67 each result display contains several tabs The results for each data stream are displayed in a separate tab In additi
264. ie m onc eet ene 207 GIE 110 F FFT AWGN channel IEEE 802 11a g OFDM 56 Carriers E Signal processing IEEE 802 11a g OFDM 56 Spectrum result display ssssesss 31 Spectrum trace data m Start offset crimson Start offset remote AA File format a E E T T 312 Files VQ data binary XML sssee 316 UO parameter XM 313 Filters lege E High pass remote High pass RF input YIG remote Format Data remote ertet re eret kennen 276 PPDU remote cocer eere 228 Free Run Trigger softkey A 110 Freq Error vs Preamble Result displays suericin rastas seat 32 Frequency Configuration remote ssssen 196 Configuration softkey sse 101 RI ul 57 Error limit remote esee 240 Frequerncy offset on iret n een rr Default nes Error limit check result remote eode G Frequency sweep measurements Config ringi ertet Pret n 147 Selectirig ier rr nre n 147 WEAN MEE 47 Frontend Configuration remote Parameters Full scale level Analog Baseband B71 remote control 192 Digital EE 95 Digital VQ remote EE 190 Unit digital Qu remote tri 191 G Gain Tracking IEEE 802 11a g OFDM 58 Gain imbalance ln Group delay FRESUIE display usa ier oreet noten 33 EA A 287 Guard inter
265. if it is to be considered in results analysis Analyzed PPDUs For statistical evaluation of PPDUs see PPDU Statistic Count No of PPDUs to Analyze on page 140 lt x gt PPDUs of totally required lt y gt PPDUs have been analyzed so far lt z gt indicates the number of analyzed PPDUs in the most recent sweep Number of recognized PPDUs global Number of PPDUs recognized in capture buffer Number of analyzed PPDUs global Number of analyzed PPDUs in capture buffer Number of analyzed PPDUS in physical chan nel Number of PPDUs analyzed in entire signal if available Pilot bit error rate 96 EVM all carriers dB EVM Error Vector Magnitude of the payload symbols over all carriers the corresponding limits specified in the standard are also indicated EVM data carriers dB EVM Error Vector Magnitude of the payload symbols over all data carriers the corresponding limits specified in the standard are also indicated EVM pilot carriers dB Center frequency error Hz EVM Error Vector Magnitude of the payload symbols over all pilot carriers the corresponding limits specified in the standard are also indicated Frequency error between the signal and the current center frequency of the R amp S FSW the corresponding limits specified in the standard are also indica ted The absolute frequency error includes the frequency error of the R amp S FSW and that of the
266. ified input connector on the front or rear panel meets or exceeds the specified trigger level See Trigger Level on page 113 Note The External Trigger 1 softkey automatically selects the trigger signal from the TRIGGER INPUT connector on the front panel For details see the Instrument Tour chapter in the R amp S FSW Getting Started manual External Trigger 1 Trigger signal from the TRIGGER 1 INPUT connector on the front panel External Trigger 2 Trigger signal from the TRIGGER 2 INPUT OUTPUT connector on the front panel Note Connector must be configured for Input in the Outputs con figuration see Trigger 2 3 on page 99 External Trigger 3 Trigger signal from the TRIGGER 3 INPUT OUTPUT connector on the rear panel Note Connector must be configured for Input in the Outputs con figuration see Trigger 2 3 on page 99 Remote command TRIG SOUR EXT TRIG SOUR EXT2 TRIG SOUR EXT3 See TRIGger SEQuence SOURce on page 209 IF Power Trigger Source Trigger Source Settings The R amp S FSW starts capturing data as soon as the trigger level is exceeded around the third intermediate frequency This trigger source is only available for RF input It is not available for input from the Digital Baseband Interface R amp S FSW B17 or the Analog Baseband Interface R amp S FSW B71 For frequency sweeps the third IF represents the start frequency The trigger band width at the th
267. ikelihood function step 2 4 5 Finally the trial parameters leading to the minimum of the log likelihood function are used as estimates 9 and d7 This robust algorithm works well even at low signal to noise ratios with the Cramer Rao Bound being reached Compensation After estimation of the parameters the sequence rn is compensated in the compensa tion blocks In the upper analyzing branch the compensation is user defined i e the user deter mines which of the parameters are compensated This is useful in order to extract the influence of these parameters The resulting output sequence is described by y s Data symbol estimation In the lower compensation branch the full compensation is always performed This separate compensation is necessary in order to avoid symbol errors After the full com pensation the secure estimation of the data symbols is performed From FFT it is clear that first the channel transfer function H must be removed This is achieved by Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM dividing the known coarse channel estimate HS calculated from the LS Usually an error free estimation of the data symbols can be assumed Improving the channel estimation In the next block a better channel estimate HL of the data and pilot sub carriers is calculated by using all nof symbols symbols of the payload PL This can be accom plished at this point because the phase is com
268. ils on the UO offset and the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Parameters lt Limit gt Range 1000000 to 1000000 Default unit DB CALCulate LIMit BURSt SYMBolerror AVERage Limit CALCulate LIMit BURSt SYMBolerror MAXimum Limit This command sets or queries the average or maximum symbol clock error limit deter mined by the default WLAN measurement For details on the symbol clock error and the default WLAN measurement see chap ter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Parameters lt Limit gt numeric value in parts per million Default unit PPM 10 5 10 Automatic Settings CONFigure POWerAUTO ME 241 CONFloure POWer AUTO SWEep TIME 242 SENSE AD JUSECON Figure DUR IIO E 242 SENSe ADJust CONFigure DURation MODE esses enne 243 IGENZGelADlust CONEioure Hv teresle LOMer e renriensieneirrinensnreniiereresrraienerenrraa 243 SENSe ADJust CONFigure HY STeresis Uber 243 ISENSeJTADJUuUSED EVEL EE 244 CONFigure POWer AUTO lt State gt This command is used to switch on or off automatic level detection When switched on level detection is performed prior to each UO data capture or measurement sweep The length of the sweep performed to determine the ideal reference level is defined by CONFigure POWer AUTO SWEep TIME on page 242 Configuring the WLAN IQ Measurement Modu
269. ime If one mea surement is running and you start another or switch to another channel the first mea surement is stopped In order to perform the different measurements you configured in multiple channels you must switch from one tab to another However you can enable a Sequencer function that automatically calls up each activa ted measurement channel in turn This means the measurements configured in the channels are performed one after the other in the order of the tabs The currently active measurement is indicated by a symbol in the tab label The result displays of the individual channels are updated in the corresponding tab as well as the Multi View as the measurements are performed Sequencer operation is independant of the currently displayed tab for example you can analyze the SEM measurement while the modulation accuracy measurement is being performed by the Sequencer For details on the Sequencer function see the R amp S FSW User Manual The Sequencer functions are only available in the MultiView tab ee Ee 86 Sequencer le E 86 Sequencer State Activates or deactivates the Sequencer If activated sequential operation according to the selected Sequencer mode is started immediately Remote command SYSTem SEQuencer on page 261 INITiate SEQuencer IMMediate on page 259 INITiate SEQuencer ABORt on page 259 Sequencer Mode Defines how often which measurements are performed The currently selected mode so
270. ing 3 Digital UO Input PLL unlocked This bit is set if the PLL of the Digital UO input is out of lock due to missing or unstable clock provided by the connected Digital UO TX device To solve the problem the Digital UO connection has to be newly initialized after the clock has been restored 4 Digital UO Input DATA Error This bit is set if the data from the Digital UO input module is erroneous Possible reasons e Bit errors in the data transmission The bit will only be set if an error occurred at the current measurement e Protocol or data header errors May occurred at data synchronization problems or vast transmission errors The bit will be set constantly and all data will be erroneous To solve the problem the Digital UO connection has to be newly initialized NOTE If this error is indicated repeatedly either the Digital UO LVDS connection cable or the receiving or transmitting device might be defect 5 not used 6 Digital UO Input FIFO Overload This bit is set if the sample rate on the connected instrument is higher than the input sam ple rate setting on the R amp S FSW Possible solution e Reduce the sample rate on the connected instrument e Increase the input sample rate setting on the R amp S FSW 7 not used 8 Digital UO Output Device connected This bit is set if a device is recognized and connected to the Digital UO Output 9 Digital UO Output Connection Protocol in progress This bit is set w
271. ing The bit pattern binary representation is converted to its equivalent integer value as the final measurement result The number of values returend for each analyzed OFDM symbol Retrieving Results corresponds to the number of data subcarriers plus the number of pilot subcariers Nsp Nsp in remote mode 0 10 9 4 5 As opposed to the graphical Bitstream results the DC and NULL carriers are not avail able in remote mode Standard CBW in Nsp Nsp Nor miz Number of data Number of pilot Total number subcarriers subcarriers of subcarriers Nsp Nsp IEEE 802 11a p 5 48 4 52 IEEE 802 11a p 10 48 4 52 IEEE 802 11a p 20 48 4 52 IEEE 802 11n 20 52 4 56 IEEE 802 11n 40 108 6 114 IEEE 802 11ac 20 52 4 56 IEEE 802 11ac 40 108 6 114 IEEE 802 11ac 80 234 8 242 IEEE 802 11ac 160 468 16 484 IEEE 802 11b and g DSSS standard DSSS physical layers For the IEEE 802 11b and g DSSS standard the data is returned in PPDU order Each PPDU is represented as a series of bytes For each PPDU the first 9 or 18 bytes represent the PLCP preamble for short and long PPDU types respectively The next 6 bytes represent the PLCP header The remaining bytes represent the PSDU Data is returned in ASCII printable hexadecimal character format TRACE 1 is used for these measurement results CCDF Complementary Cumulative Distribution Function The length of the results varies up to a maxim
272. ing Spatial Mapping Mode Spatial Expansion Power Normalise User Defined Spatial Mapping STS 1 STS 2 STS 3 STS 4 Nat Geen Spatal Mapping MOda echen 138 Power Normalisg coccion e tinea acccteategecdecteaveceti eesetnetzaresedeectbeavedecttevuecnetppetesdtas 138 User Defined EE ENEE ME 139 Spatial Mapping Mode Defines the mapping between streams and antennas For details see chapter 4 3 2 Spatial Mapping on page 69 Direct The mapping between streams and antennas is the identity matrix See also section 20 3 11 10 1 Spatial Mapping of the IEEE 802 11n WLAN standard Spatial For this mode all streams contribute to all antennas See also section Expansion 20 3 11 10 1 Spatial Mapping of the IEEE 802 11n WLAN standard User defined The mapping between streams and antennas is defined by the User Defined Spatial Mapping table Remote command CONFigure WLAN SMAPping MODE on page 223 Power Normalise Specifies whether an amplification of the signal power due to the spatial mapping is performed according to the matrix entries On Spatial mapping matrix is scaled by a constant factor to obtain a pas sive spatial mapping matrix which does not increase the total trans mitted power 5 3 9 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Off Normalization step is omitted Remote command CONFigure WLAN SMAPping NORMalise on page 223 User Defined Spatial Map
273. ing Results Query parameters lt Measurement gt ACPower MCACpower ACLR measurements also known as adjacent channel power or multicarrier adjacent channel measurements Returns the power for every active transmission and adjacent channel The order is power of the transmission channels power of adjacent channel lower upper power of alternate channels lower upper MSR ACLR results For MSR ACLR measurements the order of the returned results is slightly different power of the transmission channels total power of the transmission channels for each sub block power of adjacent channels lower upper power of alternate channels lower upper power of gap channels lower1 upper lower2 upper2 The unit of the return values depends on the scaling of the y axis logarithmic scaling returns the power in the current unit linear scaling returns the power in W CN Carrier to noise measurements Returns the C N ratio in dB CNO Carrier to noise measurements Returns the C N ratio referenced to a 1 Hz bandwidth in dBm Hz CPOWer Channel power measurements Returns the channel power The unit of the return values depends on the scaling of the y axis logarithmic scaling returns the power in the current unit linear scaling returns the power in W For SEM measurements the return value is the channel power of the reference range in the specified sub block PPOWer Peak power measurements Returns
274. ing description indicate how the setting is referred to in the Signal Field result display CBW column see Signal Field on page 43 Auto same type as first PPDU A1st The channel bandwidth of the first valid PPDU is detected and subse quent PPDUs are analyzed only if they have the same channel band width Auto individually for each PPDU Al All PPDUs are analyzed regardless of their channel bandwidth Meas only signal M Only PPDUs with the specified channel bandwidth are analyzed Demod all as signal D All PPDUs are assumed to have the specified channel bandwidth Remote command SENSe BANDwidth CHANnel AUTO TYPE on page 225 PSDU Modulation to use Specifies which PSDUs are to be analyzed depending on their modulation Only PSDUs using the selected modulation are considered in measurement analysis For details on supported modulation depending on the standard see table 4 1 Auto same All PSDUs using the same modulation as the first recognized PPDU type as first are analyzed PPDU A1st Auto individu All PSDUs are analyzed ally for each PPDU Al Meas only the Only PSDUs with the modulation specified by the PSDU Modulation specified setting are analyzed PSDU Modula tion M Demod all The PSDU modulation of the PSDU Modulation setting is used for with specified all PSDUs PSDU modula tion D Remote command SENSe DEMod FORMat BANalyze
275. int of system x2 100 y2 100 3 zoom area e g x1 60 y1 30 x2 80 y2 75 Suffix lt zoom gt 1 4 Selects the zoom window Parameters lt x1 gt lt y1 gt Diagram coordinates in of the complete diagram that define lt x2 gt lt y2 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 DISPlay WINDow lt n gt Z00M MULTiple lt zoom gt STATe State This command turns the mutliple zoom on and off User Manual 1173 9357 02 11 292 10 11 Status Registers Suffix lt zoom gt 1 4 Selects the zoom window If you turn off one of the zoom windows all subsequent zoom windows move up one position Parameters lt State gt ON OFF RST OFF Status Registers The WLAN application uses the standard status registers of the R amp S FSW depending on the measurement type However some registers are used differently Only those differences are described in the following sections For details on the common R amp S FSW status registers refer to the description of remote control basics in the R amp S FSW User Manual o RST does not influence the status registers 10 11 1 e The STATus QUEStionable SYNC Register 293 e STATUS QUE Stionable DIQ Register editar eiie 294 e Querying the Status Heglsters nennen nns 297 The STATus QUEStionable SYNC Register The STATus QUEStion
276. ion Mask measurements Return values lt TraceData gt For more information see tables below Example DISP WIND2 SEL TRAC TRACE3 Queries the data of trace 3 in window 2 Manual operation See Spectrum Emission Mask on page 49 Table 10 11 Return values for TRACE1 to TRACE6 parameter For UO data traces the results depend on the evaluation method window type selected for the current window see LAYout ADD WINDow on page 248 The results for the various window types are descri bed in chapter 10 9 4 Measurement Results for TRACe lt n gt DATA TRACE lt n gt on page 279 For RF data traces the trace data consists of a list of 1001 power levels that have been measured The unit depends on the measurement and on the unit you have currently set For SEM measurements the x values should be queried as well as they are not equi distant see TRACe lt n gt DATA X on page 279 Table 10 12 Return values for LIST parameter This parameter is only available for SEM measurements For each sweep list range you have defined range 1 n the command returns eight values in the follow ing order lt No gt lt StartFreq gt lt StopFreq gt lt RBW gt lt PeakFreq gt lt PowerAbs gt lt PowerRel gt lt PowerDelta gt lt Limit Check gt lt Unused1 gt lt Unused2 gt lt No gt range number lt StartFreq gt lt StopFreq gt start and stop frequency of the range lt RBW gt resolution bandwid
277. ird IF depends on the RBW and sweep type WLAN IQ Measurement Modulation Accuracy Flatness Tolerance For measurements on a fixed frequency e g zero span or UO measurements the third IF represents the center frequency The available trigger levels depend on the RF attenuation and preamplification A refer ence level offset if defined is also considered For details on available trigger levels and trigger bandwidths see the data sheet Remote command TRIG SOUR IFP see TRIGger SEQuence SOURce on page 209 UO Power Trigger Source Trigger Source Settings This trigger source is not available if the optional Digital Baseband Interface R amp S FSW B17 or Analog Baseband Interface R amp S FSW B71 is used for input It is also not available for analysis bandwidths 2 160 MHz Triggers the measurement when the magnitude of the sampled UO data exceeds the trigger threshold The trigger bandwidth corresponds to the Usable UO Bandwidth which depends on the sample rate of the captured UO data see Input Sample Rate on page 107 and chapter A 1 Sample Rate and Maximum Usable I Q Bandwidth for RF Input on page 307 Remote command TRIG SOUR IQP see TRIGger SEQuence SOURce on page 209 RF Power Trigger Source Trigger Source Settings Defines triggering of the measurement via signals which are outside the displayed measurement range For this purpose the instrument uses a level detector at t
278. isplay type of window 2 to be AM vs PM Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Selecting a Measurement Manual operation See AM PM on page 23 CONFigure BURSt CONSt CCARrier IMMediate This remote control command configures the result display type of window 2 to be Constellation vs Carrier Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See Constellation vs Carrier on page 28 CONFigure BURStCONSt CSYMbol IMMediate This remote control command configures the result display type of window 2 to be Constellation vs Symbol Results are only displayed after a measurement has been executed e g using the INITiate IMMediate command Usage Event Manual operation See Constellation on page 27 CONFigure BURSt EVM ECARrier IMMediate This remote control command configures the result display type of window 2 to be EVM vs Carrier Results are only displayed after a measurement is executed e g using the INIT Tiate IMMediate command Usage Event Manual operation See EVM vs Carrier on page 29 CONFigure BURSt EVM ESYMbol IMMediate IEEE 802 11b and g DSSS CONFigure BURSt EVM ECHip IMMediate Both of these commands configure the measurement type to be EVM vs Chip for IEEE 802 11b and g DSSS standards For compatibility reasons the CONFigure
279. it DBM Manual operation See Signal Level RMS on page 104 DISPlay WINDow lt n gt TRACe Y SCALe RLEVel lt ReferenceLevel gt This command defines the reference level Example DISP TRAC Y RLEV 60dBm Usage SCPI confirmed Manual operation See Reference Level on page 104 DISPlay WINDow lt n gt TRACe Y SCALe RLEVel OFFSet Offset This command defines a reference level offset Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Offset gt Range 200 dB to 200 dB RST 0dB Example DISP TRAC Y RLEV OFFS 10dB Manual operation See Shifting the Display Offset on page 104 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 page 201 If you set the attenuation manually it is no 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 This function is not available if the Digital Baseband Interface R amp S FSW B17 is active 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
280. ivates or deactivates the compensation for phase drifts If activated the measure ment results are compensated for phase drifts on a per symbol basis Remote command SENSe TRACking PHASe on page 219 Timing Error Tracking Activates or deactivates the compensation for timing drift If activated the measure ment results are compensated for timing error on a per symbol basis Remote command SENSe TRACking TIME on page 220 Level Error Gain Tracking Activates or deactivates the compensation for level drifts within a single PPDU If acti vated the measurement results are compensated for level error on a per symbol basis Remote command SENSe TRACking LEVel on page 219 UO Mismatch Compensation Activates or deactivates the compensation for UO mismatch If activated the measurement results are compensated for gain imbalance and quadra ture offset frequency dependant As a consequence UO skew impairments are com pensated as well This setting is not available for standards IEEE 802 11b and g DSSS For details see chapter 3 1 1 5 I Q Mismatch on page 19 Note For EVM measurements according to the IEEE 802 11 2012 IEEE P802 11ac D5 0 WLAN standard UO mismatch compensation must be deactivated Remote command SENSe TRACking IQMComp on page 218 Pilots for Tracking In case tracking is used the used pilot sequence has an effect on the measurement results This function is not available for IEEE
281. joint estimation proce dure Therefore each estimation parameter disturbs the estimation of the other param eter and the accuracy of the estimates is lower than the accuracy of the estimations achieved by transmit antenna baseband filter Tx filter estimation If the EVM value is dominated by Gaussian noise this method yields similar results as Cost function for signal parameters The EVM vs Symbol result display shows two traces each using a different calculation method so you can easily compare the results see EVM vs Symbol on page 30 Literature on the IEEE 802 11b Standard 1 Institute of Electrical and Electronic Engineers Part 11 Wireless LAN Medium Access Control MAC and Physical Layer PHY specifications IEEE Std 802 11 1999 Institute of Electrical and Electronic Engineers Inc 1999 2 Institute of Electrical and Electronic Engineers Part 11 Wireless LAN Medium Access Control MAC and Physical Layer PHY specifications Higher Speed Physical Layer Extensions in the 2 4 GHz Band IEEE Std 802 11b 1999 Institute of Electrical and Electronic Engineers Inc 1999 Signal Processing for MIMO Measurements IEEE 802 11ac n For measurements according to the IEEE 802 11a b g standards only a single trans mit antenna and a single receive antenna are required SISO single in single out For measurements according to the IEEE 802 11ac or n standard the R amp S FSW can measure multiple data
282. l reference See R amp S FSW User Manual gt Instrument setup gt External reference Chip clock error ppm Clock error between the signal and the chip clock of the R amp S FSW in parts per million ppm i e the chip timing error the corresponding limits specified in the standard are also indicated If possible the transmitterR amp S FSW and the DUT should be synchronized using an external reference See R amp S FSW User Manual gt Instrument setup gt External reference Rise time Time the signal needs to increase its power level from 10 to 90 of the maximum or the average power depending on the reference power setting The corresponding limits specified in the standard are also indicated Fall time Time the signal needs to decrease its power level from 90 to 10 of the maximum or the average power depending on the reference power setting The corresponding limits specified in the standard are also indicated Mean power dBm Mean PPDU power Peak power dBm Peak PPDU power Crest factor dB The ratio of the peak power to the mean power of the PPDU also called Peak to Average Power Ratio PAPR The R amp S FSW WLAN application also performs statistical evaluation over several PPDUS and displays one or more of the following results Table 3 3 Calculated summary results Result type Description Min Minimum measured value Mean Limit Mean measur
283. lation Accuracy Flatness and Tolerance Parameters for setting and query lt State gt OFF Switches the auto level detection function off ON Switches the auto level detection function on ONCE Performs an auto level measurement once immediately RST ON Manual operation See Reference Level Mode on page 103 CONFigure POWer AUTO SWEep TIME Value This command is used to specify the auto track time i e the sweep time for auto level detection This setting can currently only be defined in remote control not in manual operation Parameters for setting and query Value numeric value Auto level measurement sweep time Range 0 01 to 1 RST 0 1s Default unit S Example CONF POW AUTO SWE TIME 0 01 MS SENSe ADJust CONFigure DURation Duration In order to determine the ideal reference level the R amp S FSW performs a measurement on the current input data This command defines the length of the measurement if SENSe ADJust CONFigure DURation MODE is set to MANual Parameters lt Duration gt 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 145 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tole
284. lation settings irisi riseiras 137 DUT configuration cnet tenens 116 How to perform measurement Joined RX Sync and Tracking 118 Manual data capture 25120 Manual sequential capture 119 Normalizing power zx 198 OSP IP address tre 119 PPDU syrichronization secciones 118 Sequential capture using OSP Simultaneous capture settings Slave analyzers mu A Spatial mapping mode 20198 User defined spatial mapping 139 Modulation Melu LCE 77 Inverted UO remote 203 Inverted UO E 108 PPDU iis 126 127 133 228 PPDU remote cangrenar ia ento 301 PPBUS oet emm ode aaa 129 135 Modulation Accuracy Parameters e citet ta Een cree t ec 13 Modulation and Coding Scheme See MCS bee ER 129 135 MSR ACLR Results remote ntt 273 Multiple Measurement channels sse 85 N Ness gb E 136 220 NofSYMDOI S Em 56 Noise Additive white Gaussian AWG SOU CS c T E Normalizing Power MIMO encre treten reme tne 138 Nsts PPD S tient eegene ere Ee teats 129 130 231 Number of samples Displayed EE 11 O OBW Configuring cdma2000 sse 149 RESUS aeeai ERR TE 49 Occupied bandwidth SOG OBW EET 49 Offset Amplification ON 17 19 EE 16 RUE 102 Phase angle I Q 18 19 Quadrature cccccconccccccccccccnon
285. lay WINDow lt n gt ZOOM AREA lt x1 gt lt y1 gt lt x2 gt lt y2 gt This command defines the zoom area To define a zoom area you first have to turn the zoom on 1 Frequency Sweep iRm e 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 lt x2 gt lt y2 gt Diagram coordinates in of the complete diagram that define 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 User Manual 1173 9357 02 11 291 R amp S9FSW K91 Remote Commands for WLAN Measurements 10 10 2 2 DISPlay WINDow lt n gt ZOOM STATe State This command turns the zoom on and off Parameters State ON OFF RST OFF Example DISP ZOOM ON Activates the zoom mode Using the Multiple Zoom DISPlay WINDow n ZOOM MULTiple zoom AREA essere enne nnns 292 DiSblavlfWiNDow nztZOOM ML Tiple zoomzGTATe seenen eee eeererersrsrsrnrrrne nrn re ne 292 DISPlay WINDow lt n gt Z00M MULTiple lt zoom gt AREA lt x1 gt lt y1 gt lt x2 gt lt y2 gt This command defines the zoom area for a multiple zoom To define a zoom area you first have to turn the zoom on 1 Frequency Sweep iRm MU 1 origin of coordinate system x1 0 y1 0 2 end po
286. lay shows the power vs frequency values obtained from a FFT The FFT is performed over the complete data in the current capture buffer without any cor rection or compensation E User Manual 1173 9357 02 11 31 R amp S FSW K91 Measurements and Result Displays 2 FFT Spectrum 9 02 GHz 16 0 MHz div 5 18 GHz 3 FFT Spectrum Cem Y Rx1 Rx2 Rx3 Rx4 RTS 16 0 MHz Span 160 0 MHz CF 5 775 GHz 16 0 MHz Span 160 0 MHz 3 4Rx4 16 0 MHz Span 160 0 MHz CF 5 775 GHz i 16 0 MHz Span 160 0 MHz Fig 3 14 FFT spectrum result display for IEEE 802 11n MIMO measurements The numeric trace results for this evaluation method are described in chap ter 10 9 4 10 FFT Spectrum on page 287 Remote command LAY ADD 1 RIGH FSP see LAYout ADD WINDow on page 248 or CONFigure BURSt SPECtrum FFT IMMediate on page 181 Freq Error vs Preamble Displays the frequency error values recorded over the preamble part of the PPDU A minimum average and maximum trace are displayed User Manual 1173 9357 02 11 32 R amp S FSW K91 Measurements and Result Displays EH 2 Freq Error vs Preamble 91 Mine2 Avge 3 Max 800 0 ns Remote command LAY ADD 1 RIGH FEVP see LAYout ADD WINDow on page 248 or CONFigure BURSt PREamble IMMediate on page 180 CONFigure BURSt PREamble SELect on page 180 Group Delay Displays all Group Delay GD values recorded on a per subcarrier basis over the number o
287. leRate gt This command sets the final user sample rate for the acquired UO data Thus the user sample rate can be modified without affecting the actual data capturing settings on the R amp S FSW Note The smaller the user sample rate the smaller the usable UO bandwidth see chapter A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input on page 307 Parameters lt SampleRate gt The valid sample rates are described in chapter A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input on page 307 Range 100 Hz to 10 GHz continuously adjustable RST 32 MHz Manual operation See Input Sample Rate on page 107 10 5 4 2 Configuring Triggered Measurements The following commands are required to configure a triggered measurement in a remote environment The tasks for manual operation are described in chapter 5 3 5 2 Trigger Settings on page 108 The OPC command should be used after commands that retrieve data so that subse quent commands to change the selected trigger source are held off until after the sweep is completed and the data has been returned e Configuring the Triggering Conditions esee 204 e Configuring the Trigger O EE 211 Configuring the Triggering Conditions TRIGger SEQuence BBPowerdHOLBDoff leandra 205 TRIGH SEOuence DIME onn lA AA AAA 205 TRIGger SEQuencel HOLDOMTIMEL ooo 205 KREE ET ep EE 206 TRIGger SEQuence IFPower HYSTe
288. les inside the tar file are not changed not com pressed and thus it is possible to read the I Q data directly within the archive without the need to unpack untar the tar file first Sample iq tar files If you have the optional R amp S FSW VSA application R amp S FSW K70 some sample iq tar files are provided in the C R_S Instr user vsa DemoSignals directory on the R amp S FSW UO Data File Format iq tar Contained files An iq tar file must contain the following files UO parameter XML file e g xyz xml Contains meta information about the UO data e g sample rate The filename can be defined freely but there must be only one single UO parameter XML file inside an iq tar file UO data binary file e g xyz complex float32 Contains the binary l Q data of all channels There must be only one single UO data binary file inside an iq tar file Optionally an iq tar file can contain the following file UO preview XSLT file e g open IqTar xml file in web browser xslt Contains a stylesheet to display the UO parameter XML file and a preview of the UO data in a web browser A sample stylesheet is available at http www rohde schwarz com file open IqTar xml file in web browser xslt A 2 1 I Q Parameter XML File Specification The content of the UO parameter XML file must comply with the XML schema RsIqTar xsd available at http www rohde schwarz com file RslqTar xsd In particular the order of the XML elemen
289. level offset e attenuation e input coupling e YIG filter state 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 Apart from the settings above the following default settings are activated directly after the WLAN application is activated or after selecting Preset Channel Table 5 1 Default settings for WLAN channels Parameter Value Common WLAN settings Digital standard IEEE 802 11a Measurement WLAN UO measurement Input source RF input Attenuation 10 0 dB Capture time 1 0 ms Input sample rate 40 0 MHz Trigger mode Free run MIMO Capture method Simultaneous Channel estimation Preamble Tracking Phase Pilot tracking According to standard PPDU format Auto same type as first PPDU Channel bandwidth to mea Auto same type as first PPDU sure 5 3 2 CH EI Ee Overview WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Parameter Value MCS to use Auto same type as first PPDU Evaluations Window 2 Constellation Window 1 Magnitude Capture Configuration Overview Throughout the measurement channel configuration an overview of the most important currently defined settings is provided in the Overview The Overview is displayed when you select the Overview icon
290. llation BER Pilot Streams Fig 4 6 Results at individual processing stages Receive antenna results The R amp S FSW WLAN application can determine receive antenna results directly from the captured data at the receive antenna namely e PPDU Power e Crest factor For all other results the R amp S FSW WLAN application has to revert the processing steps to determine the signal characteristics at those stages Transmit antenna results based on the physical channel If the R amp S FSW WLAN application can determine the physical channel see chap ter 4 3 3 Physical vs Effective Channels on page 70 it can evaluate the following results e Channel Flatness based on the physical channel e Group Delay based on the physical channel e Q Offset e Quadrature Offset e Gain Imbalance Space time stream results based on the effective channel If the application knows the effective channel see chapter 4 3 3 Physical vs Effective Channels on page 70 it can evaluate the following results e Channel Flatness based on the effective channel Channels and Carriers e Group Delay based on the effective channel e EVM of pilot carriers e Constellation of pilot carriers e Bitstream of pilot carriers Spatial stream results If space time encoding is implemented the demodulated data must first be decoded to determine the following results e EVM of data carriers e Constellation diagram e Bitstream d T
291. ls see Manual Sequential MIMO Data Capture on page 119 RST RX1 Example CONFigure WLAN MIMO CAPTure BUFFer RX2 Starts capturing data from the receive antenna number 2 CONFigure WLAN MIMO CAPTure TYPE lt Method gt Specifies the method used to analyze MIMO signals Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Method gt SIMultaneous OSP MANual SiMultaneous Simultaneous normal MIMO operation OSP Sequential using open switch platform MANual Sequential using manual operation RST SIM Manual operation See MIMO Antenna Signal Capture Setup on page 116 See Manual Sequential MIMO Data Capture on page 119 CONFigure WLAN MIMO OSP ADDRess lt Address gt Specifies the TCP IP address of the switch unit to be used for automated sequential MIMO measurements The supported unit is Rohde amp Schwarz OSP 1505 3009 03 with module option 1505 5101 02 Parameters lt Address gt Manual operation See OSP IP Address on page 119 CONFigure WLAN MIMO OSP MODule ID Specifies the module of the switch unit to be used for automated sequential MIMO measurements The supported unit is Rohde amp Schwarz OSP 1505 3009 03 with mod ule option 1505 5101 02 Parameters ID A11 A12 A13 Manual operation See OSP Switch Bank Configuration on page 119 CONFigure WLAN RSYNc JOINed lt State gt This command configures how PPDU synchronization and tracking
292. lt This is only possible for single sweeps See also INI Tiate CONTinuous on page 258 Return values lt Result gt 0 PASS 1 FAIL Example INIT WAI Starts a new sweep and waits for its end CALC LIM3 FAIL Queries the result of the check for limit line 3 Usage Query only SCPI confirmed Manual operation See Spectrum Emission Mask on page 49 Retrieving Results Table 10 10 Limit line suffix lt k gt for WLAN application Suffix Limit 1to2 These indexes are not used 3 Limit line for Spectrum Emission Mask as defined by ETSI 4 Spectrum Flatness Upper limit line 5 Spectrum Flatness Lower limit line 6 Limit line for Spectrum Emission Mask as defined by IEEE 7 PVT Rising Edge max limit 8 PVT Rising Edge mean limit 9 PVT Falling Edge max limit 10 PVT Falling Edge mean limit CALCulate MARKer FUNCtion POWer lt sb gt RESult lt Measurement gt This command queries the results of power measurements This command is only available for measurements on RF data see chapter 3 2 Fre quency Sweep Measurements on page 47 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 sweeps See also INTTiate CONTinuous on page 258 Suffix lt sb gt 1 2 3 Sub block in a Multi SEM measurement for all other measure ments irrelevant Retriev
293. lt displays additional settings are available The Result Configuration softkey in the main WLAN menu opens the Result Configu ration dialog box This softkey is only available if a window with additional settins is currently selected Alternatively select a window from the Specifics for selection list in the Overview to display the Result Configuration dialog box Depending on the selected result display different settings are available Result Summary GConffguatigr ccce tear rr ee ttt edes eee 142 e Spectrum Flatness and Group Delay Configuraton rerne 143 e AM AM Confouratton eene nnn nnne 144 5 3 10 1 Result Summary Configuration You can configure which results are displayed in Result Summary displays see Result Summary Detailed on page 40 and Result Summary Global on page 41 However the results are always calculated regardless of their visibility on the screen 5 3 10 2 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance IEEE 802 1 a Result Summary Global Items Pilot Bit Error EVM All Carriers EVM Data Carriers EVM Pilot Carriers Center Frequency Error Symbol Clock Error Sida 3 Result Summary Global Fig 5 7 Result Summary Global configuration for IEEE 802 11a g OFDM standards Remote command DISPlay WINDow lt n gt TABLe ITEM on page 255 Spectrum Flatness and Group Delay Configuration For MIMO measurements Spectrum Fla
294. lue Defines the number of samples used to adjust the length of the smoothing filter for PVT measurement This command is only available for IEEE 802 11b g DSSS standards Parameters Value Manual operation See PVT Average Length IEEE 802 11b g DSSS on page 141 CONFigure BURSt PVT RPOWer Mode This remote control command configures the use of either mean or maximum PPDU power as a reference power for the 802 11b g DSSS PVT measurement Parameters Mode MEAN MAXimum Manual operation See PVT Reference Power IEEE 802 11b g DSSS on page 141 CONFigure WLAN PAYLoad LENGth SRC Source Defines which payload length is used to determine the minimum or maximum number of required data symbols IEEE 802 11n ac Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Source gt ESTimate HTSignal ESTimate Uses a length estimated from the input signal HTSignal IEEE811 02 n Determines the length of the HT signal from the signal field LSIGnal IEEE811 02 ac Determines the length of the L signal from the signal field Manual operation See Source of Payload Length IEEE 802 11 ac n on page 140 CONFigure WLAN PVERror MRANge lt Range gt This remote control command queries whether the Peak Vector Error results are calcu lated over the complete PPDU or just over the PSDU This command is supported for 802 11b and 802 11g
295. lumn represents one antenna s transmissions over time thus the term space time encoder This means each block represents the same data but with a different coding The resulting blocks are referred to as space time streams STS Each stream is sent to a different Tx antenna This diversity coding increases the signal to noise ratio at the receive antenna The pilot carriers are inserted after the data carriers went through the STBC Thus only the data carriers are decoded by the analyzer to determine characteristics of the demodulated data see also figure 4 6 In order to transmit the space time streams two or more antennas are required by the sender and one or more antennas are required by the receive antenna 4 3 2 Spatial Mapping The Spatial Encoder see figure 4 3 is responsible for the spatial multiplexing It defines the mapping between the streams and the transmit antennas referred to as Spatial mapping or as a matrix the spatial mapping matrix In the R amp S FSW WLAN application the mapping can be defined using the following methods e Direct mapping one single data stream is mapped to an exclusive Tx antenna The spatial matrix contains 1 on the diagonal and otherwise zeros e Spatial Expansion multiple different data streams are assigned to each antenna in a defined pattern e User defined mapping the data streams are mapped to the antennas by a user defined matrix User defined spatial mapping You can d
296. lyzed Auto individually for each PPDU Al All PPDUs are analyzed Meas only the specified MCS M Only PPDUs with the MCS index specified for the MCS Index setting are analyzed Demod all with specified MCS D The MCS Index setting is used for all PPDUs Remote command SENSe DEMod FORMat MCSindex MODE on page 230 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance MCS Index Defines the MCS index of the PPDUs taking part in the analysis manually This field is enabled for MCS index to use Meas only the specified MCS or Demod all with specified MCS Remote command SENSe DEMod FORMat MCSindex on page 230 STBC Field Defines the PPDUs taking part in the analysis according to the Space Time Block Cod ing STBC field content Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display STBC column see Signal Field on page 43 Auto same type as first PPDU A1st All PPDUs using a STBC field content identical to the first recognized PPDU are analyzed Auto individually for each PPDU Al All PPDUs are analyzed Meas only if STBC field 1 1 Stream M1 IEEE 802 11N Only PPDUs with the specified STBC field content are analyzed Meas only if STBC field 2 2 Stream M2 IEEE 802 11N Only PPDUs with the specified STBC field content are analyzed Demod all as STBC field
297. lyzed IEEE 802 11 ac only DB5 All PPDUs are analyzed within a channel bandwidth of 5MHz IEEE 802 11 a p only DB10 All PPDUs are analyzed within a channel bandwidth of 10MHz IEEE 802 11 a p only DB20 All PPDUs are analyzed within a channel bandwidth of 20MHz DB40 All PPDUs are analyzed within a channel bandwidth of 40MHz IEEE 802 11 n ac only DB80 All PPDUs are analyzed within a channel bandwidth of 80MHz IEEE 802 11 n ac only DB160 All PPDUs are analyzed within a channel bandwidth of 160MHz Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance IEEE 802 11 n ac only RST FBURst Example SENS BAND CHAN AUTO TYPE MB20 Manual operation See Channel Bandwidth to measure CBW on page 126 SENSe DEMod FORMat BANalyze lt Format gt Specifies which PSDUs are to be analyzed depending on their modulation Only PSDUs using the selected modulation are considered in result analysis Note to analyze all PPDUs that are identical to the first detected PPDU corresponds to Auto same type as first PPDU use the command SENS DEMO FORM BANA BTYP AUTO TYPE FBUR To analyze all PPDUs regardless of their format and modulation corresponds to Auto individually for each PPDU use the command SENS DEMO FORM BANA BTYP AUTO TYPE ALL See SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 Pa
298. mand SENSe DEMod FFT OFFSet on page 217 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 7 Tracking and Channel Estimation The channel estimation settings determine which channels are assumed in the input signal Tracking settings allow for compensation of some transmission effects in the signal see Tracking the phase drift timing jitter and gain on page 58 Channel Estimation Le IE DHT BR TO ENT GITE Preamble Tracking Tracking for the signal to be measured Phase Timing Off Level Off e IQ Mismatch Compensation Off Pilots for Tracking According to Standard E Channel Estimation Fange 22 icis esie dieee cease seen tope dap seen nannten eth Rn d 122 Phase TVACKING 24 225 M 123 Timing Error Tracking canens oiea EA A ATER 123 Level Error Gain Tracking iii dado 123 UO Mismatch Compensation rn nn naar rrnnnanana nn 123 Pilots for Kee e DEE 123 Channel Estimation Range Specifies the signal range used to estimate the channels This function is not available for IEEE 802 11b or g DSSS Preamble The channel estimation is performed in the preamble as required in the standard Payload The channel estimation is performed in the preamble and the pay load The EVM results can be calculated more accurately Remote command SENSe DEMod CESTimation on page 218 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Phase Tracking Act
299. maximum number of symbols the payload may contain see SENSe DEMod FORMat BANalyze SYMBols MAX on page 238 and SENSe DEMod FORMat BANalyze SYMBols MIN on page 238 Parameters State ON OFF RST OFF Manual operation See Equal PPDU Length on page 140 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance SENSe DEMod FORMat BANalyze SYMBols MAX lt NumDataSymbols gt For IEEE 802 11a g OFDM ac n p signals only If the SENSe DEMod FORMat BANalyze SYMBols EQUal command is set to false this command specifies the maximum number of payload symbols allowed for a PPDU to take part in measurement analysis The number of payload symbols is defined as the uncoded bits including service and tail bits If the SENSe DEMod FORMat BANalyze SYMBols EQUal command has been set to true then this command has no effect Parameters lt NumDataSymbols gt RST 64 Manual operation See Min Max No of Data Symbols IEEE 802 11a g OFDM ac n p on page 141 SENSe DEMod FORMat BANalyze SYMBols MIN lt NumDataSymbols gt For IEEE 802 11a g OFDM ac n p signals only If the SENSe DEMod FORMat BANalyze SYMBols EQUal command has been set to true then this command specifies the exact number of payload symbols a PPDU must have to take part in measurement analysis If the SENSe DEMod FORMat
300. mber of transmit antennas e The spatial mapping matrices are singular to working precision PPDUs are dismissed due to inconsistencies Hint PPDU requires at least one payload symbol Currently at least one payload symbol is required in order to successfully analyze the PPDU Null data packet NDP sounding PPDUs will generate this message Hint PPDU dismissed due to a mismatch with the PPDU format to be analyzed The properties causing the mismatches for this PPDU are highlighted Hint PPDU dismissed due to truncation The first or the last PPDU was truncated during the signal capture process for exam ple Hint PPDU dismissed due to HT SIG inconsistencies One or more of the following HT SIG decoding results are outside of specified range MCS index Number of additional STBC streams Number of space time streams derived from MCS and STBC CRC Check failed Non zero tail bits Hint PPDU dismissed because payload channel estimation was not possible The payload based channel estimation was not possible because the channel matrix is singular to working precision Hint Channel matrix singular to working precision Channel equalizing for PPDU Length Detection fully and user compensated measure ment signal is not possible because the estimated channel matrix is singular to work ing precision Common Suffixes 10 Remote Commands for WLAN Measure ments The following commands are required to perform
301. mit for the parameter was exceeded Usage Query only CALCulate LIMit BURSt EVM DATA AVERage RESult CALCulate LIMit BURSt EVM DATA MAXimum RESult This command returns the result of the average or maximum EVM limit check for data carriers The limit value is defined by the standard or the user see CALCulate LIMit BURSt EVM DATA MAXimum on page 240 Return values lt LimitCheck gt PASS The defined limit for the parameter was not exceeded FAILED The defined limit for the parameter was exceeded Usage Query only CALCulate LIMit BURSt EVM PlLot AVERage RESult CALCulate LIMit BURSt EVM PlLot MAXimum RESult This command returns the result of the average or maximum EVM limit check for pilot carriers The limit value is defined by the standard or the user see CALCulate LIMit BURSt EVM PILot MAXimum on page 240 Return values lt LimitCheck gt PASS The defined limit for the parameter was not exceeded FAILED The defined limit for the parameter was exceeded Usage Query only CALCulate LIMit BURSt FERRor AVERage RESult CALCulate LIMit BURSt FERRor MAXimum RESult This command returns the result of the average or maximum center frequency error limit check The limit value is defined by the standard or the user see CALCulate LIMit BURSt FERRor MAXimum on page 240 Return values lt LimitCheck gt PASS The defined limit for the parameter was not exceeded FAILED The defined limit
302. mmand LAY ADD 1 RIGH SFI see LAYout ADD WINDow on page 248 or CONFigure BURSt STATistics SFIeld IMMediate on page 182 Spectrum Flatness The Spectrum Flatness trace is derived from the magnitude of the estimated channel transfer function Since this estimated channel is calculated from all payload symbols of the PPDU it represents a carrier wise mean gain of the channel Assuming that we have a cable connection between the DUT and the R amp S FSW that adds no residual channel distortion the Spectrum Flatness shows the spectral distortion caused by the DUT for example the transmit filter This result display is not available for single carrier measurements IEEE 802 11b g DSSS The diagram shows the absolute power per carrier All 57 carriers are displayed including the unused carrier 0 In contrast to the SISO measurements in previous Rohde amp Schwarz signal and spec trum analyzers the trace is no longer normalized to 0 dB scaled by the mean gain of all carriers 2 Spectrum Flatness Carrier 250 50 1 Carrier Carrier 250 For more information see chapter 4 3 6 Crosstalk and Spectrum Flatness on page 75 IESSE User Manual 1173 9357 02 11 46 R amp S FSW K91 Measurements and Result Displays 2 Spectrum Flatness Stream 1 4 Rx1 4 Stream 1 Rx 1 4 Stream 2 Rx 1 4 Stream 3 Rx 1 4 Stream 4 Rx 1 4 f 2 1 Stream l Rx 1 2 2 Stream 1 Rx 2 2 3 Stream 1 Rx 3 2 4 Stream 1 Rx 4 Carrier 25
303. more a coarse estimate Af coarse Of the Rx Tx frequency offset Af is derived from the metric in 6 The hat generally indicates an estimate e g x is the estimate of x This can easily be understood because the phase of r i A r i N is deter mined by the frequency offset As the frequency deviation Af can exceed half a bin distance between neighboring sub carriers the preceding short symbol SS is also analyzed in order to detect the ambiguity After the coarse timing calculation the time estimate is improved by the fine timing calculation This is achieved by first estimating the coarse frequency response DIS where k 26 26 denotes the channel index of the occupied sub carriers First the FFT of the LS is calculated After the FFT calculation the known symbol information of the LS sub carriers is removed by dividing by the symbols The result is a coarse esti mate of the channel transfer function In the next step the complex channel impulse response is computed by an IFFT Then the energy of the windowed impulse response the window size is equal to the guard period is calculated for each trial time After wards the trial time of the maximum energy is detected This trial time is used to adjust the timing Determing the payload window Now the position of the LS is known and the starting point of the useful part of the first payload symbol can be derived In the next block this calculated time instant is used to positi
304. mple Rate and Bandwidth with Activated UO Bandwidth Extension Option B500 The bandwidth extension option R amp S FSW B500 provides measurement bandwidths up to 500 MHz Sample rate Maximum UO bandwidth 100 Hz to 600 MHz proportional up to maximum 500 MHz 600 MHz to 10 GHz 500 MHz UO Data File Format iq tar UO bandwidths for RF input Usable UO bandwidth MHz 500 Activated option cel OO 3 3 B500 m E y a H ATI THILEIHE AA NN RR kal um Output sample 200 280 360 440 520 600 10000 rate fout MHz Fig 1 3 Relationship between maximum usable I Q bandwidth and output sample rate for active R amp S FSW B500 A 2 VQ Data File Format iq tar UO data is packed in a file with the extension iq tar An iq tar file contains l 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 UO data from the meta information while still having both inside one file In addition the file format allows you to preview the UO 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 can 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 fi
305. n See STBC Field on page 130 SENSe BANDwidth CHANnel AUTO TYPE lt Bandwidth gt This remote control command specifies the bandwidth in which the PPDUs are ana lyzed This command is only available for standards IEEE 802 11a ac n Note that channel bandwidths larger than 10 MHz require a R amp S FSW bandwidth extension option see chapter A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input on page 307 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Bandwidth gt FBURst ALL MB5 MB10 MB20 MB40 MB80 MB160 DB5 DB10 DB20 DB40 DB80 DB160 FBURSt The channel bandwidth of the first valid PPDU is detected and subsequent PPDUs are analyzed only if they have the same channel bandwidth corresponds to Auto same type as first PPDU ALL All PPDUs are analyzed regardless of the channel bandwidth corresponds to Auto individually for each PPDU MB5 Only PPDUs within a channel bandwidth of 5MHz are analyzed IEEE 802 11 a p only MB10 Only PPDUs within a channel bandwidth of 10MHz are analyzed IEEE 802 11 a p only MB20 Only PPDUs within a channel bandwidth of 20MHz are analyzed MB40 Only PPDUs within a channel bandwidth of 40MHz are analyzed IEEE 802 11 n ac only MB80 Only PPDUs within a channel bandwidth of 80MHz are analyzed IEEE 802 11 ac only MB160 Only PPDUs within a channel bandwidth of 160MHz are ana
306. n the demodulation settings of the application Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS uoneums3 Joqui s uoneunsy3 uoneuins3 uoneuins3 ules eseug basy But uogewnsa peuonnied peuonnied peuonnied 1914 J9y sue uoneljjsuo eubis sjueuuieduuj Ol WAS SI9 9QweJed le Jo uoneuns 3 uajdwesey uonoaog Buri Bueyi4 uonoeuo u0I 284102 1 fiequ pueqeseg ules eseyd bai4 uoneuins3 101114 J841928M uoneuins 3 uogeuins3 eseyd bai But y AO i I T I ajdwesa uonoe4102 jp ud E eseug baly Sun ZHP S Ps AO Jayngajdwes s singuoess aqe ou uf 4ayng eunjdeo OJ 1940 SIS euyald Fig 4 2 Signal processing for IEEE 802 11b or g DSSS signals Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS Once the the normalized and undisturbed reference signal is available the transmit antenna baseband filter Tx filter is estimated by minimizing the cost function of a maximum likelinood based estimator N 1 Eu 2 E j2nzM v j H H L r v xe sei _ Y h i x s v i 0 jOg v 0 i L transmit antenna baseband filter Tx filter estimation 4 9 where r v the oversampled measurement signal Ss v the normalized oversampled power of the undisturbed reference signal N the observation length L the filter length Af v the variation parameters of the frequency offset Ad the variation parameters of th
307. n 179 CONFloure BURGCEVMESvMbolt MMediatel nennen 179 CONFloure BURG bb ambiet MMedatel nennen 180 GONFigure BURSPPREAMBIESEMCC EE 180 CONFloure BURGCPVTTlMMedatel eee eee tececeeeeeeeeeeeeeeeeeeeeeeeeesananaea 180 CONFigure BURSEPV I E 180 CONFigure BURSEtSPECtrum FFT IMMediate 1 reiciendise unus a nae ENNER EEN 181 CONFigure BURSt SPECtrum FLATness SELect eese eeesne nennt nitent 181 CONFigure BURSt SPECtrum FLATness IMMediate csse 182 CONFigure BURStSTATistics BSTReam IMMediate sse 182 CONFloure BURG GTATletice GEledt MMediatel nen 182 DISPlay WINDow lt n gt SELeCt ccccceccee eee eee ecetececeeeeeeeeeeeeeeeeeeeeeeesesaeaeaaaaaaeaaenenenenes 182 CONFigure BURSt AM AM IMMediate This remote control command configures the result display type of window 2 to be AM vs AM Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See AM AM on page 23 CONFigure BURSt AM EVM IMMediate This remote control command configures the result display type of window 2 to be AM vs EVM Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See AM EVM on page 24 CONFigure BURSt AM PM IMMediate This remote control command configures the result d
308. n is shown below in figure 4 2 The baseband signal of an IEEE 802 11b or g DSSS wireless LAN system transmit antenna is sampled with a sample rate of 44 MHz The first task of the measurement application is to detect the position of the PPDU within the measurement signal r4 v The detection algorithm is able to find the the beginning of short and long PPDUs and can distinguish between them The algorithm also detects the initial state of the scrambler which is not specified by the IEEE 802 11 standard If the start position of the PPDU is known the header of the PPDU can be demodula ted The bits transmitted in the header provide information about the length of the PPDU and the modulation type used in the PSDU Once the start position and the PPDU length are fully known better estimates of timing offset timing drift frequency offset and phase offset can be calculated using the entire data of the PPDU At this point of the signal processing demodulation can be performed without decision error After demodulation the normalized in terms of power and undisturbed reference signal s v is available If the frequency offset is not constant and varies with time the frequency offset and phase offset in several partitions of the PPDU must be estimated and corrected Addi tionally timing offset timing drift and gain factor can be estimated and corrected in several partitions of the PPDU These corrections can be switched off individually i
309. n marks You can use a single quotation mark or a double quotation mark Example INSTRument DELete Spectrum 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 10 3 Activating WLAN Measurements 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 Activating WLAN Measurements WLAN measurements require a special application on the R amp S FSW R amp S FSW K91 The measurement is started immediately with the default settings o These are basic R amp S FSW commands listed here for your convenience INS Tr ment GREate DDPElcale nr rr rtr re ero ed eee eco ieu event 173 EEN Tit ge E E 173 IN Trument ChRtatehRtblace etes n nsssh isi sse niii esr sss aa sis ann sn se 174 Lane ier Eer GE 174 INS TrumenbLiS E 174 leegen 176 INS Trameni SELESA
310. n physical chan nel Peak vector error Peak vector error EVM over the complete PPDU including the preamble in and in dB calculated according to the IEEE 802 11b or g DSSS definition of the normalized error vector magnitude see Peak Vector Error IEEE method on page 21 The corresponding limits specified in the standard are also indicated PPDU EVM EVM Error Vector Magnitude over the complete PPDU including the pream ble in and dB 1 Q offset dB Transmitter center frequency leakage relative to the total Tx channel power see chapter 3 1 1 1 I Q Offset on page 16 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 3 1 1 1 Parameter Gain imbalance dB Description Amplification of the quadrature phase component of the signal relative to the amplification of the in phase component see chapter 3 1 1 2 Gain Imbal ance on page 17 Quadrature error Measure for the crosstalk of the Q branch into the I branch see Gain imbal ance UO offset quadrature error on page 65 Center frequency error Hz Frequency error between the signal and the current center frequency of the R amp S FSW the corresponding limits specified in the standard are also indica ted The absolute frequency error includes the frequency error of the R amp S FSW and that of the DUT If possible the transmitterR amp S FSW and the DUT should be synchronized using an externa
311. n the Save Recall menu which is displayed when you select the Save or Open icon in the tool bar For a description of the other functions in the Save Recall menu see the R amp S FSW User Manual lues a n 152 il TRIO MP I 153 EXPO E 153 Ei 01 02 MEE NOT 153 Import Provides functions to import data 7 2 How to Export and Import I Q Data UO Import Import Opens a 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 UO data such as the UO Analyzer or optional applications Note that the I Q data must have a specific format as described in the R amp S FSW UO Analyzer and UO Input User Manual Remote command MMEMory LOAD 1Q STATe on page 288 Export Opens a submenu to configure data export UO Export Export Opens a 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 UO data such as the UO 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
312. nae nr sna maa x naa nba Ra E oca REA SEENEN 267 al ler Re TEE E EE 268 FETCHBURSTOUADofset MAXIMUM osa 268 FETCh BURGrOUADoftserMiNmmmum a akai aa iaaa a aak 268 FETCEBURSERMS LAVER JE cnica Aa 268 FEIGIEBURSERMS ER dl CET KE 268 FETCHBURSERMS MINIMUM Z cia riada 268 Retrieving Results FETCh BURSt SYMBolerror AVERage nn nn nnnnnnnns 268 FETCH BURSESY MBole ror MAXIMUM KE 268 FETCHIBURSES MBGIErrOr MINIMUM cocinada 268 UNI EYN EE 268 UNIT EIST 268 FETCh BURSt ALL This command returns all results from the default WLAN measurement Modulation Accuracy Flatness and Tolerance see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 The results are output as a list of result strings separated by commas in ASCII format The results are output in the following order Return values lt Results gt lt preamble power gt lt payload power gt lt min rms power gt lt average rms power gt lt max rms power gt lt peak power gt lt min crest factor gt lt average crest factor gt lt max crest factor gt lt min frequency error gt lt average frequency error gt lt max frequency error gt lt min symbol error gt lt average symbol error gt lt max symbol error gt lt min IQ offset gt lt average IQ offset gt lt maximum IQ offset gt lt min gain imbalance gt lt average gain imbalance gt lt max gain imbalance gt lt min quadrature offset gt lt average q
313. nal 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 FSW User Manual Parameters 1 lt FileName gt String containing the path and name of the target file Example MMEM STOR IQ STAT 1 C R_S Instr user data ig tar Stores the captured UO data to the specified file Manual operation See Q Export on page 153 10 10 Analysis The following commands define general result analysis settings concerning the traces and markers in standard WLAN measurements Currently only one Clear Write trace and one marker are available for standard WLAN measurements Analysis 10 10 1 Analysis for RF measurements General result analysis settings concerning the trace markers lines etc for RF meas urements are identical to the analysis functions in the Spectrum application except for some special marker functions and spectrograms which are not available in the WLAN application For details see the General Measurement Analysis and Display chapter in the R amp S FSW User Manual LECCE RC 290 e Zooming into the Display terere etn ether tkm Innen an th ELA nanc s 291 Markers Markers help you analyze your measurement results by determining particular values in the diagram Currently only 1 marker per window can be configured for standard WLAN measurements CALCulate n MARKer m STATe
314. ncy value of the reference clock Remote commands exclusive to digital UO data input and output NPU DIOS CDEVC p E 189 INPUDIQ RANGe UPPE AUTO inir rl a 190 INPUEDIQURANGe COU PING E 190 INPUT DIO RANGE UPPE EE 190 INPut DIQ RANGe UPPernUNIT cuicos iia 191 le Rene VE 191 UP LC SRA Ee Em 191 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance INPut DIQ CDEVice This command queries the current configuration and the status of the digital UO input from the optional Digital Baseband Interface R amp S FSW B17 For details see the section Interface Status Information for the Digital Baseband Inter face R amp S FSW B17 in the R amp S FSW UO Analyzer User Manual Return values lt ConnState gt Defines whether a device is connected or not 0 No device is connected 1 A device is connected lt DeviceName gt Device ID of the connected device lt SerialNumber gt Serial number of the connected device lt PortName gt Port name used by the connected device lt SampleRate gt Maximum or currently used sample rate of the connected device in Hz depends on the used connection protocol version indica ted by lt SampleRateType gt parameter lt MaxTransferRate gt Maximum data transfer rate of the connected device in Hz lt ConnProtState gt State of the connection protocol which is used to identify the connected device Not Started Has to be Started Started Passed Failed Done lt PR
315. nd provide various types of output such as noise or trigger signals RF Input Protection The RF input connector of the R amp S FSW must be protected against signal levels that exceed the ranges specified in the data sheet Therefore the R amp S FSW is equipped with an overload protection mechanism This mechanism becomes active as soon as the power at the input mixer exceeds the specified limit It ensures that the connection between RF input and input mixer is cut off When the overload protection is activated an error message is displayed in the status bar INPUT OVLD and a message box informs you that the RF Input was discon nected Furthermore a status bit bit 3 in the STAT QUES POW status register is set In this case you must decrease the level at the RF input connector and then close the message box Then measurement is possible again Reactivating the RF input is also possible via the remote command INPut ATTenuation PROTection RESet Input from Noise Sources The R amp S FSW provides a connector NOISE SOURCE CONTROL with a voltage sup ply for an external noise source By switching the supply voltage for an external noise source on or off in the firmware you can activate or deactive the device as required External noise sources are useful when you are measuring power levels that fall below the noise floor of the R amp S FSW itself for example when measuring the noise level of an amplifier In this case you c
316. nd the emis sions and their distance to the limit be identified Note The WLAN 802 11 standard does not distinguish between spurious and spectral emissions For details see chapter 5 4 2 Spectrum Emission Mask on page 148 Ref Level 41 00 dBm Offset 40 00 dB 1 Spectrum Emission Mask CF 2 1 GHz 1001 pts 2 55 MHz Span 25 5 MHz 2 Result Summary W CDMA 3GPP DL Tx Power 33 74 dBm Tx Bandwidth 3 840 MHz RBW 1 000 MHz Range Low Range Up Frequency Power Abs Power Rel ALimit MHz 000 MHz 000 MHz 2 09153 GHz 39 37 dBm 73 11 dB 18 61 dB 2 4 000 MHz E 2 2 09494 GHz 39 75 dBm 73 48 dB 22 98 dB 15 MHz d 2 09642 GHz 50 91 dBm 84 65 dB 21 15 dB 15 MHz 30 0 z 2 09652 GHz 51 84 dBm 85 57 dB 22 65 dB 15 MH 30 0 2 09739 GHz 52 33 dBm 86 07 dB 34 57 dB MHz mz 2 10259 GHz 49 37 dBm 83 11 dB 31 61 dB 515 MHz 30 0 z 2 10342 GHz 50 68 dBm 84 42 dB 22 27 dB 4 000 MH i 2 10373 GHz 51 81 dBm 85 55 dB 22 05 dB 000 MHz J T 2 10439 GHz 38 64 dBm 72 37 dB 21 87 dB 50 MHz 000 MHz 2 11026 GHz 39 24 dBm 72 97 dB 18 47 dB Fig 3 28 SEM measurement results Remote command CONFigure BURSt SPECtrum MASK IMMediate on page 183 Querying results CALCulate LIMit lt k gt FAIL on page 272 TRAC DATA LIST see TRACe lt n gt DATA on page 277 Occupied Bandwidth The Occupied Bandwidth OBW measurement determines the bandwidth in which in default settings 99 of the total signal power is to be found The percentage
317. ndwidth reaches the bandwidth of the analog IF filter at very high output sample rates the curve breaks Relationship between sample rate and usable UO bandwidth Up to the maximum bandwidth the following rule applies Usable LO bandwidth 0 8 Output sample rate The figure 1 1 shows the maximum usable I Q bandwidths depending on the output sample rates R amp S FSW without additional bandwidth extension options sample rate 100 Hz 10 GHz maximum UO bandwidth 10 MHz Table 1 1 Maximum I Q bandwidth Sample rate Maximum UO bandwidth 100 Hz to 10 MHz proportional up to maximum 10 MHz 10 MHz to 10 GHz 10 MHz Sample Rate and Maximum Usable UO Bandwidth for RF Input R amp S FSW with options B28 or U28 I Q Bandwidth Extension sample rate 100 Hz 10 GHz maximum bandwidth 28 MHz Sample rate Maximum UO bandwidth 100 Hz to 35 MHz proportional up to maximum 28 MHz 35 MHz to 10 GHz 28 MHz R amp S FSW with option B40 or U40 I Q Bandwidth Extension sample rate 100 Hz 10 GHz maximum bandwidth 40 MHz Sample rate Maximum UO bandwidth 100 Hz to 50 MHz proportional up to maximum 40 MHz 50 MHz to 10 GHz 40 MHz R amp S FSW with option B80 or U80 I Q Bandwidth Extension sample rate 100 Hz 10 GHz maximum bandwidth 80 MHz Sample rate Maximum UO bandwidth 100 Hz to 100 MHz proportional up to maximum 80 MHz 100 MHz to 10 GHz 80 MHz R amp
318. ned antenna to each R amp S FSW To define a particular starting point for the FFT or to improve the measurement speed for signals with a low duty cycle select the Synchronization OFDM Demod button and set the required parameters Select the Tracking Channel Estimation button to define how the data channels are to be estimated and which distortions will be compensated for e g crosstalk between the MIMO antennas at the DUT Select the Demod button to provide information on the modulated signal and how the PPDUs detected in the capture buffer are to be demodulated Select the MIMO tab in the Demodulation dialog box to define which spatial mapping mode is used that is how the space time streams are mapped to the antennas a If necessary include a time shift for the individual antennas b If the signal power is amplified according to the maxtrix entries so that the total transmitted power is not increased the measured powers can be normalised to consider this effect in demodulation 8 3 12 13 14 15 16 How to Determine the OBW SEM ACLR or CCDF for WLAN Signals Select the Evaluation Range button to define which data in the capture buffer you want to analyze Select the Display Config button and select the displays that are of interest to you up to 16 Arrange them on the display to suit your preferences Exit the SmartGrid mode For the master analyzer only Activate the NOISE SOURCE out
319. ngs define which PPDUs are analyzed This setting is automatically selected when any of the subsequent settings are changed to a value other than Auto Remote command SENSe DEMod FORMat BCONtent AUTO on page 230 PPDU Format to measure Defines which PPDU formats are to be included in the analysis Depending on which standards the communicating devices are using different formats of PPDUs are availa ble Thus you can restrict analysis to the supported formats Note The PPDU format determines the available channel bandwidths For details on supported PPDU formats and channel bandwidths depending on the standard see table 4 1 Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display Format column see Signal Field on page 43 Auto same type as first PPDU A1st The format of the first valid PPDU is detected and subsequent PPDUS are analyzed only if they have the same format Auto individually for each PPDU AI All PPDUs are analyzed regardless of their format Meas only M Only PPDUs with the specified format are analyzed Demod all as D All PPDUs are assumed to have the specified PPDU format Remote command SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE on page 228 SENSe DEMod FORMat BANalyze on page 227 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Channel Bandwidth to measur
320. niiiiin aiiai 183 CONFigure BURStSTATistics CCDF IMMediate sees 183 CONFigure BURSt SPECtrum ACPR IMMediate This remote control command configures the result display in window 2 to be ACPR adjacent channel power relative Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See Channel Power ACLR on page 48 CONFigure BURSt SPECtrum MASK IMMediate This remote control command configures the result display in window 2 to be Spectrum Mask Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See Spectrum Emission Mask on page 49 CONFigure BURSt SPECtrum OBWidth IMMediate This remote control command configures the result display in window 2 to be ACPR adjacent channel power relative Results are only displayed after a measurement is executed e g using the INITiate IMMediate command Usage Event Manual operation See Occupied Bandwidth on page 49 CONFigure BURSt STATistics CCDF IMMediate This remote control command configures the result display in window 2 to be CCDF conditional cumulative distribution function Results are only displayed after a mea surement is executed e g using the INTTiate IMMediate command 10 5 10 5 1 Usage Event Manual operation See CCDF on page 50 Configuring the WLAN IQ Mea
321. nitless and phase rad values interleaved Requires DataType float32 or f1oat64 DataType Specifies the binary format used for samples in the UO data binary file see DataFilename element and chapter A 2 2 I Q Data Binary File on page 316 The following data types are allowed e int8 8bit signed integer data int16 16 bit signed integer data int32 32 bit signed integer data float32 32 bit floating point data IEEE 754 float64 64 bit floating point data IEEE 754 ScalingFactor Optional describes how the binary data can be transformed into values in the unit Volt The binary UO data itself has no unit To get an UO 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 1 Q Data File Format iq tar Element NumberOfChan nels Description Optional specifies the number of channels e g of a MIMO signal contained in the 1 Q data binary file For multi channels the UO samples of the channels are expected to be interleaved within the UO data file see chapter A 2 2 I Q Data Binary File on page 316 If the NumberOfChannels element is not defined one channel is a
322. nt determines the bandwidth that the signal occu pies The occupied bandwidth is defined as the bandwidth in which in default settings 99 of the total signal power is to be found The percentage of the signal power to be included in the bandwidth measurement can be changed 5 4 4 Frequency Sweep Measurements For further details about the Occupied Bandwidth measurements refer to Measuring the Occupied Bandwidth in the R amp S FSW User Manual To restore adapted measurement parameters the following parameters are saved on exiting and are restored on re entering this measurement e Reference level and reference level offset e RBW VBW e Sweep time e Span CCDF The CCDF measurement determines the distribution of the signal amplitudes comple mentary cumulative distribution function The CCDF and the Crest factor are dis played For the purposes of this measurement a signal section of user definable length is recorded continuously in zero span and the distribution of the signal ampli tudes is evaluated The measurement is useful to determine errors of linear amplifiers The crest factor is defined as the ratio of the peak power and the mean power The Result Summary dis plays the number of included samples the mean and peak power and the crest factor The CCDF measurement is performed as in the Spectrum application with the follow ing settings Table 5 6 Predefined settings for WLAN CCDF measurements
323. ntial Manual OSP Switch Box Setup OSP IP Address OSP Switch Bank Configuration 3 TX Antenna DUT Connecting 3 RF antenna s via an OSP Switch Box to the Analyzer K15 K16 669 666 OJOJJOJoJE KA AAA Fig 5 1 Connection instructions for sequential MIMO using an OSP switch The diagram shows an R amp S OSP B101 option fitted in one of the three module slots at the rear of the OSP switch platform The DUT Tx antennas the OSP switching box and the analyzer have to be connected as indicated in the diagram User Manual 1173 9357 02 11 118 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance e Blue colored arrows represent the connections between the Tx antennas of the DUT and the corresponding SMA plugs of the R amp S OSP B101 option e Green colored arrows represent auxiliary connections of SMA plugs of the R amp S OSP B101 option e Yellow colored arrows represent the connection between the SMA plug of the R amp SGOSP B101 option with the RF or analog baseband input of the analyzer OSP IP Address Sequential Using OSP Switch Setup The analyzer and the R amp S OSP switch platform have to be connected via LAN Enter the IP address of the OSP switch platform When using an R amp S amp OSP130 switch platform the IP address is shown in the front dis play When using a R SOOSP120 switch platform connect an external monitor to get the IP address or use the default IP address of the OSP swi
324. o KG Trade names are trademarks of the owners The following abbreviations are used throughout this manual R amp S9FSW is abbreviated as R amp S FSW R amp S FSW K91 Contents Contents E 5 1 1 About this Manual lt lt lt lt lt lt lt ici ie cuna aacra renes Drm RR Rd 5 1 2 Documentation Overvlew 2 aerei nnus in etnia iesu nc mun RR srianan 6 1 3 Conventions Used in the Documentation eese nnn 7 2 Welcome to the WLAN Application eene 9 2 1 Starting the WLAN Application ecce nnne nnn nnns 9 2 2 Understanding the Display Information eere nnn 10 3 Measurements and Result Displays eeeeeeeee 13 3 1 WLAN I Q Measurement Modulation Accuracy Flatness and Tolerance 13 3 2 Frequency Sweep Measurements ecccccececeeeeeeeeeeeeneeeeeeeeeeeeseeesseeneaneeseeeeeneens 47 4 Measurement BasiCcs eee ree u ee rece aea ue teinte nea ariete 54 4 1 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM 54 42 Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS 61 4 3 Signal Processing for MIMO Measurements IEEE 802 11ac n 67 AA Channels and Carrlers iiie erunt eeu cn na iai u auno sa iua u ane Ea sacs unes raa u nna np ada ecE 75 4 5 Recognized vs Analyzed
325. o simplify the description Retrieving Results 96 Zz uonenbe Z OZ YEW 120 0981 1 Z208d 3331 9 S6 zc uonenbe ZLOZ YJE 120 0981 1 Z208d 3331 s v6 2z uonenbe zLOZ YEW 120 0981 1Z208d 3331 p 6S 0Z uonenbe zLOZ 11 Z08 PIS 3331 SJOLEoqnSs jolld 0L OL zz uonoes ZLOZ YEW 120 981 1 Z08d 3331 Z SISLUE9QNS jolld OL LL E 0Z uonoes ZLOZ 11 Z08 PIS 3331 1 Sjuejs u00 peyejas Bulwl G zz eger ZLOZ up L ZQ 281 L Z08d 3331 LL LLL GAL O L Ei vL EG SZ LL LL GZ eS 9 801 8ZL Ov Sjuejs u09 pejejaJ Buiuui G zz eger ZLOZ YEW L Zqjoer 1 Z08d 3331 H ZS 0 L ER e z 42 23 v eS v9 oz eL Sjuejsuoo pejejoJ Buiuui 9 0z e qe1 qeL ZL0Z 11 Z08 PIS 3321 LL LLL lb 013 vL es SZ LL LL SZ eg 9 801 8ZL Ov Sjuejsuoo pejejoJ Buiuui 9 0z ail Gel ZLOZ LL 208 PIS 3321 Pi ZS 0 L ER ALS 22 123 v zS v9 0c ULL SJojeujeJed payejas Bulwl s g1 e q81 981 ZL0Z 11 208 PIS dal LL S 0 L eS c 42 23 D 9r v9 oz sjajeweJed poejejoJ Buiuui 6 9 e q81 qeL ZL0Z 11 Z08 PIS 3321 LL eS 0 L E IL Le D 9r v9 0L SJojeujeJed pojejaJ Butuui G 8L e q81 Gel ZL0Z 11 208 PIS 3321 LL S 0 L eS IL Le D 9r v9 g dep dSN aSy NN 194 5s jn 51904 pasny 1 N 9S 1esqns IER os Jo 9s jo id 5s ejep 144g P9SN JO ON ny Jo ON ON JO ON Jo ON zn piep yu wwog Paen N Pony 194 INN SN s 1aLesqns jot ZEN HEN HIN M99 ues
326. o writes a 1 into the associated bit of the corresponding EVENt register Status Registers 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 Setting parameters lt BitDefinition gt Range 0 to 65535 STATus QUEStionable DIQ EVENt lt ChannelName gt This command queries the contents of the EVENt section of the STATus QUEStionable DIO register for IQ measurements Readout deletes the contents of the EVEN 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 Example STAT QUES DIQ Usage Query only 10 11 3 Querying the Status Registers The following commands are required to query the status of the R amp S FSW and the WLAN application For details on the common R amp S FSW status registers refer to the description of remote control basics in the R amp S FSW User Manual e General Status Register Commande 297 e Reading Out thie E 298 e Reading Out the CONDition Part 298 e Controlling the ENABle Part 299 e Controlling the Negative Transition Part ai ariadna 299 e Controlling the Positive Transition Part 300 10 11 3 1 General Status Register Commands STANO EE 298 Ch TT un KEE 298 10 11 3 2 10 11 3 3 Status Registers STATus PRESet
327. ococononononnononannnnnnnnnn nana nanannnnncn 214 CONFloure WAN ANTMatrtv ANTenna Analyzerz nenne 214 CONFigure WLAN ANTMatrix STATe state cnn nnnnnans 214 CONFigure WLARED E e arios 215 CONFloure WAN MIMO CAbTure eee eeeeeteteceeeeeeeeeeeeeeeeeeeaeeesesasanaaaaae 215 CONFigure WLANIMIMO CAPTUre BUPPFBI arroz ce tuae dez eot AAA 215 GONFigure WLAN MIMO CAPTUre TYPE 2 ao 215 CONFloure WAN MIMO OGbP ADtDtess etienne nennen niaaa iaaa 216 CONFigure WLAN MIMO OSP MODul8 senes nnn tr nnt nennen 216 GONFig reWLANIRSYNe OLIN amp dg 2 i itio terrere ete aia 216 CONFigure WLAN ANTMatrix ADDRess lt add gt Address This remote control command specifies the TCP IP address for each receiver path in IPV4 format Note it is not possible to set the IP address of ANTMatrix1 Master Parameters Address TCP IP address in IPV4 format Manual operation See Analyzer IP Address on page 117 CONFigure WLAN ANTMatrix ANTenna lt Analyzer gt Antenna This remote control command specifies the antenna assignment of the receive path Parameters Antenna ANTenna1 ANTenna2 ANTenna3 ANTenna4 Antenna assignment of the receiver path Example CONF WLAN ANTM ANT2 ANT1 Analyzer number 2 measures antenna no 1 CONF WLAN ANTM ANTA ANT2 Analyzer number 42 measures antenna no 2 Manual operation See Assignment on page 117 CONFigure WLAN ANTMatrix STATe lt state gt lt State gt This remot
328. of the estimations see also Error vector magnitude EVM R amp S FSW method on page 65 Remote command LAY ADD 1 RIGH EVCH see LAYout ADD WINDow on page 248 or CONFigure BURSt EVM ECHip IMMediate on page 179 CONFigure BURSt EVM ESYMbol IMMediate on page 179 EVM vs Symbol This result display shows all EVM values calculated on a per carrier basis over the number of analyzed PPDUs as defined by the Evaluation Range gt Statistics settings see PPDU Statistic Count No of PPDUs to Analyze on page 140 The Tracking Channel Estimation according to the user settings is applied see chapter 5 3 7 Tracking and Channel Estimation on page 122 The MinHold Maxhold and Aver age traces are displayed User Manual 1173 9357 02 11 30 R amp S FSW K91 Measurements and Result Displays EH 2 EVM vs Symbol 1 Mine 2 Avg e 3 Mae Symb 1 595 2 Symb Symb 5952 2 EVM vs Symbol Stream 1 4 Stream 1 Stream 2 Stream 3 Stream 4 2 1 Stream 1 2 2 Stream 2 Symb 1 35 352 Symb 1 35 2 Symb 2 3 Stream 3 2 4 Stream 4 52 Symb 1 35 2 Symb Fig 3 13 EVM vs symbol result display for IEEE 802 11n MIMO measurements This result display is not available for single carrier measurements IEEE 802 11b g DSSS Remote command LAY ADD 1 RIGH EVSY see LAYout ADD WINDow on page 248 or CONFigure BURSt EVM ESYMbol IMMediate on page 179 FFT Spectrum This result disp
329. oined Rx Synchronization and Tracking L Analyzer IP Addiese iii ii 117 E UL EET EE 117 L Joined RX Syne and Tracking eessesetein rata rtn tnrba nbn taa s 118 sequential Using E e TEE 118 e E 119 L OSP Switch Bank Configuration sscscscscsecesecssecesecesecssseeeeseneseeeees 119 Manual Sequential MIMO Data Caplle catt ici aci 119 oo Jie EI 120 Ro 10 0o c 120 L Clear All Magnitude Capture Butters sess 120 L RUN SGL RUN CONT updates 120 DUT MIMO Configuration Defines the number of Tx antennas of the device under test DUT Currently up to eight Tx antennas are supported Remote command CONFigure WLAN DUTConfig on page 215 MIMO Antenna Signal Capture Setup Defines the MIMO method used by the R amp S FSW s to capture data from multiple Tx antennas sent by one device under test DUT Simultaneous Simultaneous normal MIMO operation The number of Tx antennas set in DUT MIMO Configuration defines the number of analyzers required for this measurement setup WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Sequential Sequential using open switch platform using OSP A single analyzer and the Rohde amp Schwarz OSP Switch Platform Switch with at least one fitted R amp S amp OSP B101 option is required to mea sure the number of DUT Tx Antennas as defined in DUT MIMO Con figuration Sequential Sequential using manual operation manual A single analyzer is required
330. om the antennas matches with the expected antennas Otherwise the secondary diagonal will contain the useful traces Remote command CONFigure WLAN ANTMatrix ANTenna lt Analyzer gt on page 214 R amp S FSW K91 Configuration Joined RX Sync and Tracking Simultaneous Signal Capture Setup This command configures how PPDU synchronization and tracking is performed for multiple captured antenna signals ON RX antennas are synchronized and tracked together OFF RX antennas are synchronized and tracked separately Remote command CONFigure WLAN RSYNc JOINed on page 216 Sequential Using OSP Switch Setup A single analyzer and the Rohde amp Schwarz OSP Switch Platform with at least one fitted RSSOOSP B101 option is required to measure the DUT Tx Antennas Note For sequential MIMO measurements the DUT has to transmit identical PPDUs over time The signal field for example has to be identical for all PPDUs For details see chapter 4 3 4 1 Sequential MIMO Measurement on page 72 This setup requires the analyzer and the OSP switch platform to be connected via LAN A connection diagram is shown to assist you in connecting the specified number of DUT Tx antennas with the analyzer via the Rohde amp Schwarz OSP switch platform WAN TR OM Signal Capture Trigger Source Trigger In Out MIMO Capture DUT MIMO Config 3 Tx Antennas MIMO Antenna Signal Capture Setup Simultaneous o Sequential using OSP Switch Box e Seque
331. om the modulation and coding scheme MCS as defined in the WLAN 802 11 standard is displayed here This information is for reference only for example so you can determine the required data rate Guard Interval Length Defines the PPDUs taking part in the analysis depending on the guard interval length Note The terms in brackets in the following description indicate how the setting is referred to in the Signal Field result display Gl column see Signal Field on page 43 Auto same type as first PPDU A1st All PPDUs using the guard interval length identical to the first recog nized PPDU are analyzed Auto individually for each PPDU Al All PPDUs are analyzed Meas only Short MS Only PPDUS with short guard interval length are analyzed Meas only Long ML Only PPDUS with long guard interval length are analyzed Demod all as short DS All PPDUs are demodulated assuming short guard interval length Demod all as long DL All PPDUs are demodulated assuming long guard interval length Remote command CONFigure WLAN GTIMe AUTO on page 221 CONFigure WLAN GTIMe AUTO TYPE on page 221 CONFigure WLAN GTIMe SELect on page 222 5 3 8 5 Demodulation MIMO IEEE 802 11ac n The MIMO settings define the mapping between streams and antennas This tab is only available for the standard IEEE 802 11ac or n MIMO WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Demodulation MIMO Spatial Mapp
332. omain trigger sources 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 114 zu TRIGger SEQuence SOURce Source This command selects the trigger source For details on the available trigger sources see Trigger Source Settings on page 109 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Source gt IMMediate Free Run EXTernal Trigger signal from the TRIGGER INPUT connector EXT2 Trigger signal from the TRIGGER INPUT OUTPUT connector Note Connector must be configured for Input EXT3 Trigger signal from the TRIGGER 3 INPUT OUTPUT connector Note Connector must be configured for Input RFPower First intermediate frequency Not available for input from the Digital Baseband Interface R amp S FSW B17 or the Analog Baseband Interface R amp S F
333. ompo nent l The in phase component of the input signal is filtered and resampled to the sample rate of the application If the center fre quency is not O see SENSe FREQuency CENTer on page 196 the in phase component of the input signal is down converted first Low IF I Q The quadrature component of the input signal is filtered and resampled to the sample rate of the application If the center fre quency is not 0 the quadrature component of the input signal is down converted first Low IF Q RST IQ INP IO TYPE Q See Q Mode on page 97 CALibration AIQ DCOFfset Offset This command defines a DC offset of the input from the Analog Baseband interface R amp S FSW B71 Parameters Offset Example numeric value DC offset RST 0 Default unit V CAL AIQ DCOF I 0 001 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance CALibration AIQ DCOFfset Q Offset This command defines a DC offset of the Q input from the Analog Baseband interface R amp S FSW B71 Parameters lt Offset gt numeric value DC offset RST 0 Default unit V Example CAL AIQ DCOF Q 0 001 SENSe PROBe lt ch gt SETup CMOFfset lt CMOffset gt Sets the common mode offset The setting is only available if a differential probe is connected to the R amp S FSW If the probe is disconnected the common mode offset of t
334. on an overview tab is provided in which all data streams are displayed at once in individual subwind ows 1 Magnitude Capture RX1 4 Rx 1 Rx2 Rx3 Rx4 1 1 RX 1 Freq 5 775 GHz Att 24 dB PASO 1 2 Rx 2 Freq 5 775 GHz Att 24 dB PA30 0 0s 5 0 ms 0 0s 1 3 Rx 3 Freq 5 775 GHz Att 24 db PASO 1 4 Rx 4 Freq 5 775 GHz Att 24 dB PA30 5 0 ms 0 0 s Fig 3 16 Magnitude Capture display for MIMO measurement with 4 Rx antennas For the Magnitude Capture display each subwindow contains additional information for each Rx antenna namely e Antenna number Center frequency Mechanical attenuation ATT in dB Electronical attenuation EL in dB Reference offset EXT in dB Preamplification PA in dB Numeric trace results are not available for this evaluation method Remote command LAY ADD 1 RIGH CMEM see LAYout ADD WINDow on page 248 Phase Error vs Preamble Displays the phase error values recorded over the preamble part of the PPDU A mini mum average and maximum trace are displayed User Manual 1173 9357 02 11 35 R amp S FSW K91 Measurements and Result Displays EH 2 Phase Error vs Preamble ei Mine 2 Avge3 Max 800 0 ns Remote command LAY ADD 1 RIGH PEVP see LAYout ADD WINDow on page 248 or CONFigure BURSt PREamble IMMediate on page 180 CONFigure BURSt PREamble SELect on page 180 PLCP Header IEEE 802 11b g GSSS This result display shows the decoded data from the PL
335. on the payload window Only the payload part is windowed This is sufficient because the payload is the only subject of the subsequent measurements In the next block the windowed sequence is compensated by the coarse frequency estimate Af course This is necessary because otherwise inter channel interference ICI would occur in the frequency domain The transition to the frequency domain is achieved by an FFT of length 64 The FFT is performed symbol wise for each symbol of the payload nof_symbols The calcula ted FFTs are described byr with e 1 nof symbols as the symbol index e k 31 32 as the channel index In case of an additive white Gaussian noise AWGN channel the FFT is described by 4 5 common timing E JCphase phase y E GE SE Xa x 81 xH E TEE FFT 4 1 with Koa the modulation dependant normalization factor User Manual 1173 9357 02 11 56 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM e aj the symbol of sub carrier k at symbol e g the gain at the symbol in relation to the reference gain g 1 at the long symbol LS e H the channel frequency response at the long symbol LS e phase common the common phase drift phase of all sub carriers at symbol see Common phase drift e phase n9 the phase of sub carrier k at symbol caused by the timing drift see Common phase drift e D the independent Gaussian distributed noise samples
336. only the useful signal is analyzed all signal data in adjacent channels is removed by the filter This setting improves the signal to noise ratio and thus the EVM results for signals with strong or a large number of adjacent channels However for some measurements information on the effects of adjacent channels on the measured signal may be of interest Parameters lt State gt ON OFF 0 1 RST 1 Manual operation See Suppressing Filter out Adjacent Channels IEEE 802 11a g OFDM ac n p on page 108 SENSe SWAPiq State This command defines whether or not the recorded IQ pairs should be swapped I lt gt Q 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 FSW can do the same to compensate for it Parameters State ON and Q signals are interchanged Inverted sideband Q j l OFF and Q signals are not interchanged Normal sideband I j Q RST OFF Manual operation See Swap UO on page 108 SENSe SWEep TIME lt Time gt This command defines the sweep or data capture time Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Time gt refer to data sheet RST depends on current settings determined automati cally Example SWE TIME 10s Usage SCPI confirmed Manual operation See Capture Time on page 107 TRACe IQ SRATe lt Samp
337. or example B40 extends the bandwidth to 40 MHz Note that the U options as of U40 always require all lower bandwidth options as a pre requisite while the B options already include them Max usable Required B option Required U option s Q BW 10 MHz 28 MHz B28 U28 The bandwidth extension option R amp S FSW B320 U320 requires a reference board revision 3 14 or higher The bandwidth extension option R amp S FSW B500 requires a reference board 1312 8075 06 revision 4 06 or higher and a motherboard 1313 4180 02 or 1313 7698 02 REESEN User Manual 1173 9357 02 11 307 Sample Rate and Maximum Usable UO Bandwidth for RF Input Max usable Required B option Required U option s UO BW 40 MHz B40 U28 U40 or B28 U40 80 MHz B80 U28 U40 U80 or B28 U40 U80 or B40 U80 160 MHz B160 U28 U40 U80 U160 or B28 U40 U80 U160 or B40 U80 U160 or B80 U160 320 MHz B320 U28 U40 U80 U160 U320 or B28 U40 U80 U160 U320 or B40 U80 U160 U320 or B80 U160 U320 or B160 U320 500 MHz B500 See data sheet The bandwidth extension option R amp S FSW B320 U320 requires a reference board revision 3 14 or higher The bandwidth extension option R amp S FSW B500 requires a reference board 1312 8075 06 revision 4 06 or higher and a motherboard 1313 4180 02 or 1313 7698 02 As a rule the usable UO bandwidth is proportional to the output sample rate Yet when the UO ba
338. oseis tU ubi er ege verse exu best ess neveu gege ne eus dea 227 SENSe DEMod FORMatBANalyze BTYP96 rcnt e dt pede Arai 301 SENSe DEMod FORMat BANalyze BTYPe AUTO TE 228 SENSe DEMod FORMat BANalyze DBYTes EQUal 235 SENSe DEMod FORMat BANalyze DBYTeS MAX cceccesseeeceeeeneceeesseceecaeceessesaeesaecseeeaeeaeseneeaeeeaesaeeaes 235 SENSe DEMod FORMat BANalyze DBYTes MIN esent nnne 236 SENSe DEMod FORMat BANalyze DURation EQUal eese 236 SENSe DEMod FORMat BANalyze DURation MAX essere nere 236 SENSe DEMod FORMat BANalyze DURation MIN esee nennen 237 SENSe DEMod FORMat BANalyze SYMBols EQUal seen 237 SENSe DEMod FORMat BANalyze SYMBols MAX SENSe DEMod FORMat BANalyze SYMBols MIN eese SENSe IBEMOd FORMGaEMGSInQOX conrra rene SENSe DEMod FORMatMGSindexMOBE tare iterat e eet p tec ege D pee c e SENSe DEMod FORMat NSTSindex SENSe DEMod FORMat NSTSindex MODE SENSe DEMod FORMat BCONItent AUTO ier ripper ttp rene tbe ei t t Cd gen SENSE TER d E ISENSE JFRE QUENCY CENT 6 E SENSe JFREQuency CEN Fer STEP cia SENSe JFREQu ncy CENTERSTEP AU TO uti ca lin se e Pea Es SENSe FREQuency OFFSet SENS Te Ve e SENSe PROBSSChsiSE Tup le E E SENSO E TL EE SENSe JSWESp COUN EE SENSO EEN EE SENSE TRACKINGHOMGOMP EE SENSe T
339. otherwise some PPDUs may not be detected Parameters lt State gt ON OFF 0 1 ON 1 A coarse burst search is performed based on the power levels of the input signal OFF 0 No pre evaluation is performed the entire signal is processed RST 1 Manual operation See Power Interval Search on page 121 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 10 5 6 Tracking and Channel Estimation SENSE DEMOd CES TIMA OM E 218 SENSe TRACKking QMCOMP oraninin rada anciana animas 218 SENSE TRACKS LE E 219 SENSe e e BEE 219 SENSE TRAC IIOP TEE 219 SENSO TRACKing TIME 2 2 ntc rutscht eim bkn dd 220 SENSe DEMod CESTimation State This command defines whether channel estimation will be done in preamble and pay load or only in preamble The effect of this is most noticeable for the EVM measure ment results where the results will be improved when this feature is enabled However this functionality is not supported by the IEEE 802 11 standard and must be disabled if the results are to be measured strictly according to the standard Parameters State ON OFF ON The channel estimation is performed in the preamble and the payload The EVM results can be calculated more accurately OFF The channel estimation is performed in the preamble as required in the standard RST OFF Manual operation See Channel Estimation Range on page 122 SENSe TRACking IQMComp
340. p SGDiglConf Software Operating Manual Note If you close the R amp S DiglConf window using the Close icon the window is minimized not closed If you select the File gt Exit menu item in the R amp S DiglConf window the application is closed Note that in this case the settings are lost and the EX IQ BOX functionality is no longer available until you restart the application using the DiglConf softkey in the R amp S FSW once again WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Analog Baseband Input Settings The following settings and functions are available to provide input via the Analog Base band Interface R amp S FSW B71 in the applications that support it Input Source Power Sensor External Generator Probes Frequency Input Settings External Mixer T O Mode Input Config Digital IQ swap 1 0 md Analo 9 Signal Path Baseband Analog E S310 Center Frequency For more information on the Analog Baseband Interface R amp S FSW B71 see the R amp S FSW UO Analyzer and UO Input User Manual Analog Baseband Input Sfate 2 cient aeree reete re pendet er a aed 97 JieXz oT M 97 Justen le te iei drerit A ER Ld ede 98 Cagter Frequeliey xr eot ce itn Reda AA 98 Analog Baseband Input State Enables or disable the use of the Analog Baseband input source for measurements Analog Baseband is only available if the Analog Baseband Interface R
341. page 123 Determining the error parameters log likelihood function How can the parameters above be calculated In this application the optimum maxi mum likelihood algorithm is used In the first estimation step the symbol independent parameters A fes and are estimated The symbol dependent parameters can be User Manual 1173 9357 02 11 58 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM neglected in this step i e the parameters are set to g 1 and dy 0 Referring to FFT the log likelihood function L must be calculated as a function of the trial parame ters Af est and 7 The tilde generally describes a trial parameter Example X is the trial parameter of x nof _ symbols Lfe Y Y l 1 k 21 7 7 21 ini 2 A E common timin g LS J phase phase rap XH xe with Phase As N INxAf T x1 Phase 9 InxN Nx xkxl Log likelihood function step 1 4 4 The trial parameters leading to the minimum of the log likelihood function are used as estimates Ai and In Log likelihood function step 1 the known pilot symbols a are read from a table In the second step the log likelihood function is calculated for every symbol as a func tion of the trial parameters 8 and dr EE E DEN common ti min g LS Bhas phas ny a XgixH xe Ly g dy gt k 21 7 7 21 with Phase og x N IN x Af T xl dy phase 9 2n7xN Nx xkxl Log l
342. page 243 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 243 SENSe ADJust CONFigure DURation on page 242 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 243 5 3 12 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 on page 243 Sweep Settings The sweep settings define
343. pe gt DEVice Sends a trigger signal when the R amp S FSW 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 100 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 trigger port 2 front 3 trigger port 3 rear Usage Event Manual operation See Send Trigger on page 100 OUTPut TRIGger lt port gt PULSe LENGth lt Length gt This command defines the length of the pulse generated at the trigger output Suffix lt port gt Selects the trigger port to which the output is sent 2 trigger port 2 front 3 trigger port 3 rear Parameters lt Length gt Pulse length in seconds Manual operation See Pulse Length on page 100 10 5 4 3 MIMO Capture Settings The following commands are only available for IEEE 802 11ac n standards Useful commands for defining MIMO capture settings described elsewhere e CALCulate lt n gt BURSt IMMediate on page 258 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Remote commands exclusive to defining MIMO capture settings CONFloure WAN ANTMatrtv ADDtess add cooccccccccncccncoc
344. pensated and the data symbols are known The long observation interval of nof_symbols symbols compared to the short interval of 2 symbols for the estimation of HS leads to a nearly error free channel estimate In the following equalizer block AS is compensated by the channel estimate The resulting channel compensated sequence is described by ys The user may either choose the coarse channel estimate HS from the long symbol or the nearly error free channel estimate DL from the payload for equalization If the improved esti mate H9 is used a 2 dB reduction of the subsequent EVM measurement can be expected According to the IEEE 802 11a measurement standard 6 the coarse channel estima tion AS from the long symbol has to be used for equalization Therefore the default setting of the R amp S FSW WLAN application is equalization from the coarse channel estimate derived from the long symbol Calculating error parameters In the last block the parameters of the demodulated signal are calculated The most important parameter is the error vector magnitude of the sub carrier k of the current packet EY 1 nof packets EVM z EVM counter nof packets uA Error vector magnitude of the subcarrier k in current packet 4 6 Furthermore the packet error vector magnitude is derived by averaging the squared EVM versus k 26 EVM LU 3 EVM k 26 k 0 Error vector magnitude of the entire packet 4 7
345. ping Define your own spatial mapping between streams and antennas For each antenna Tx1 4 the complex element of each STS Stream is defined The upper value is the real part part of the complex element The lower value is the imagi nary part of the complex element Additionally a Time Shift can be defined for cyclic delay diversity CSD Remote command CONFigure WLAN SMAPping TX ch on page 223 CONFigure WLAN SMAPping TX ch STReam stream on page 224 CONFigure WLAN SMAPping TX ch TIMeshift on page 224 Evaluation Range The evaluation range defines which objects the result displays are based on Evaluation Range i Statistics PPDU Statistic Count No of PPDU s to Analyze Time Domain Source of Payload Length Equal PPDU Length Min Payload Length Max Payload Length 66000 us PVT Average Length m Peak Vector Error IEEE Meas Range Fig 5 6 Evaluation range settings for IEEE 802 11b and g DSSS standards PPDU Statistic Count No of PPDUs to Anahyze 140 Source of Payload Lengthi lEEE 802 11 AC m ctm eere ets 140 Equal PPDU Lengt eccerre trien det te Pede vote 140 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Min Max No of Data Symbols IEEE 802 11a g OFDM ac n p 141 Min Max Payload Length IEEE 802 11b g DSSS cette pais tenet 141 PVT Average Length IEEE 802 11b g DSS S i n 141 P
346. ple 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 e Usable I Q Analysis bandwidth the bandwidth range in which the signal remains undistorted in regard to amplitude characteristic and group delay this range can be used for accurate analysis by the R amp S FSW e Record length Number of UO samples to capture during the specified measure ment time calculated as the measurement time multiplied by the sample rate For the UO data acquisition digital decimation filters are used internally The passband of these digital filters determines the maximum usable VO bandwidth In consequence signals within the usable UO bandwidth passband remain unchanged while signals outside the usable UO 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 UO bandwidth o Bandwidth extension options The maximum usable UO bandwidth provided by the R amp S FSW 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 f
347. plication are highlighted by the green bars R amp S FSW K91 um Signal Capture Trigger Source Trigger In Out MIMO Capture DUT MIMO Config 3 Tx Antennas MIMO Antenna Signal Capture Setup Simultaneous Cal Sequential using OSP Switch Box Ee Sequential Manual Sequential Signal Capture Overview Rx 1 Capture Rx 2 Capture mc Rx 3 Capture Calc Results Clear All Magnitude Capture Buffers ESTE eR re ed TT RAN LEIT EICH Capture Memory Rx 1 Remote command CONF WLAN MIMO CAPT TYP MAN see CONFigure WLAN MIMO CAPTure TYP on page 215 Single Cont Manual Sequential MIMO Data Capture Configuration El Starts a single or continuous new measurement for the corresponding antenna Remote command CONF WLAN MIMO CAPT RX1 see CONFigure WLAN MIMO CAPTure on page 215 INITiate IMMediate on page 259 Calc Results Manual Sequential MIMO Data Capture Calculates the results for the captured antenna signals Remote command CALCulate lt n gt BURSt IMMediate on page 258 Clear All Magnitude Capture Buffers Manual Sequential MIMO Data Capture Clears all the capture buffers and previews RUN SGL RUN CONT updates Manual Sequential MIMO Data Capture Determines which capture buffer is used to store data if a measurement is started via the global RUN SGL RUN CONT keys on the front panel of the R amp S FSW User Manual 1173 9357 02 11 120 WLAN I
348. plifier can be activated for the RF input signal You can use a preamplifier to analyze signals from DUTs with low input power This function is not available for input from the Digital Baseband Interface R amp S FSW B17 For R amp S FSW 26 or higher models the input signal is amplified by 30 dB if the pream plifier is activated For R amp S FSW 8 or 13 models the following settings are available Off Deactivates the preamplifier 15 dB The RF input signal is amplified by about 15 dB 30 dB The RF input signal is amplified by about 30 dB Remote command INPut GAIN STATe on page 202 INPut GAIN VALue on page 202 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 5 Signal Capture Data Acquisition 3 5 1 You can define how much and how data is captured from the input signal EE eeler EE 107 e Trigger SUING EEN 108 MIMO Capture lee EE 115 General Capture Settings The general capture settings define how much and which data is to be captured during the WLAN IQ measurement WW Signal Capture Trigger Source Trigger In Out Input Sample Rate Capture Time Swap IQ Filter Filter out Adjacent Channels MEUS IMPE E 107 Captura TE 107 SO E A N 108 Suppressing Filter out Adjacent Channels IEEE 802 11a g OFDM ac n p 108 Input Sample Rate This is the sample rate the R amp S FSW WLAN application expects the UO input data to have If necessary the
349. programming Online help is available using the Y icon on the toolbar of the R amp S FSW Web Help The web help provides online access to the complete information on operating the R amp S FSW and all available options without downloading The content of the web help corresponds to the user manuals for the latest product version The web help is availa ble from the R amp S FSW product page at http www rohde schwarz com product FSW html Downloads Web Help Getting Started This manual is delivered with the instrument in printed form and in PDF format on the CD 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 FSW product page at http www2 rohde schwarz com product FSW 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 FSW in general and the
350. put for the connection to the R amp S FS Z11 Trigger Unit For an R amp S FSW as a master analyzer a Press the INPUT OUTPUT key b Select Output Config c Select Noise Source On Trigger a new sweep by pressing the TRIG MANUAL button on the Trigger Unit The data is captured from all antennas automatically The data is collected by the master R amp S FSW which evaluates the entire data and updates the result displays for the individual data streams when the measurement is stopped How to Determine the OBW SEM ACLR or CCDF for WLAN Signals Press the MODE key on the front panel and select the WLAN application The R amp S FSW opens a new measurement channel for the WLAN application UO data acquisition is performed by default Select the Signal Description button to define the digital standard to be used Select the required measurement a Press the MEAS key on the front panel b In the Select Measurement dialog box select the required measurement The selected measurement is activated with the default settings for WLAN immedi ately For SEM measurements select the required standard settings file a In the SEMask menu select the Standard Files softkey b Select the required settings file The subdirectory displayed in the file selection dialog box depends on the standard you selected in step step 2 If necessary adapt the settings as described for the individual measurements in the R amp S FSW User
351. r 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 provided only for compatibility to remote control programs from WLAN applications on previous signal analyzers For new remote control pro grams use the specified alternative commands The CONF BURS lt ResultType gt IMM commands used in former R amp S Signal and Spectrum Analyzers to change the result display are still supported for compatibility reasons however they have been replaced by the LAY ADD WIND commands in the R amp S FSW see chapter 10 7 Configuring the Result Display on page 247 Note that the CONF BURS lt ResultType gt IMM commands change the screen layout to display the Magnitude Capture buffer in window 1 at the top of the screen and the selected result type in window 2 below that MMEMon LOAD SEM STAT 6 aman n rra nn nn sese a rana nn nn nn 300 SENSe DEMod FORMat BANzahvze Rive 301 TRIGge e D 302 MMEMory LOAD SEM STATe lt 1 gt lt Filename gt This command loads a spectrum emission mask setup from an xml file Note that this command is maintained for compatibility reasons only Use the SENS ESP PRES command for new remote control programs See the R amp S FSW User Manual Remote commands for SEM measurem
352. r download from the Rohde amp Schwarz website on the R amp S FSW product page at http www2 rohde schwarz com product FSW html gt Downloads gt Firmware Conventions Used in the Documentation Typographical Conventions The following text markers are used throughout this documentation 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 Conventions Used in the Documentation 1 3 2 Conventions for Procedure Descriptions When describing how to operate the instrument several alternative methods may be available to perform the same task In this case the procedure using the touchscreen is described Any elements that can be activated by touching can also be clicked using an additionally connected mouse The alternative procedure using the keys on the instrument or the on screen keyboard is only described if it deviates from the standard operating procedur
353. rameters lt Format gt RST QAM64 Example SENS DEMO FORM BAN BPSK6 Manual operation See PPDU Format to measure on page 125 See PSDU Modulation to use on page 126 See PSDU Modulation on page 127 See PPDU Format to measure PSDU Modulation to use on page 132 See PPDU Format on page 133 Table 10 4 Modulation format parameters for IEEE 802 11a y OFDM or p standard SCPI parameter Dialog parameter BPSK6 BPSK 1 2 BPSK9 BPSK 3 4 QPSK12 QPSK 1 2 QPSK18 QPSK 3 4 QAM1624 16 QAM 1 2 QAM1636 16 QAM 3 4 QAM6448 64 QAM 2 3 QAM6454 64 QAM 3 4 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Table 10 5 Modulation format parameters for IEEE 802 11b or g DSSS standard SCPI parameter Dialog parameter CCK11 Complementary Code Keying at 11 Mbps CCK55 Complementary Code Keying at 5 5 Mbps DBPSK1 Differential Bl Phase shift keying DQPSK2 Differential Quadrature phase shift keying PBCC11 PBCC at 11 Mbps PBCC22 PBCC at 11 Mbps PBCC55 PBCC at 5 5 Mbps SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE lt Analysis gt This remote control command specifies how signals are analyzed Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Analysis gt Example FBURst ALL MMIX MGRF DMIX DGRF MVHT DVHT MNHT DNHT FBURst The format of the first
354. rance SENSe ADJust CONFigure DURation MODE lt Mode gt In order to determine the ideal reference level the R amp S FSW performs a measurement on the current input data This command selects the way the R amp S FSW determines the length of the measurement Parameters lt Mode gt AUTO The R amp S FSW determines the measurement length automati cally according to the current input data MANual The R amp S FSW uses the measurement length defined by SENSe ADJust CONFigure DURation on page 242 RST AUTO Manual operation See Resetting the Automatic Measurement Time Meastime Auto on page 145 See Changing the Automatic Measurement Time Meastime Manual on page 145 SENSe ADJust CONFigure HYSTeresis LOWer Threshold When the reference level is adjusted automatically using the SENSe ADJust LEVel on page 244 command 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 measurement before the reference level is adapted auto matically Parameters Threshold Range O dB to 200 dB RST 1 dB 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 Man
355. rd iaa 199 CONFloure POWer ENbeched RE 199 DISPlay WINDow lt n gt TRACe Y SCALe RLEVel cee eeececeee eee cecaeaeae eee ener 199 DISPlay WINDow lt n gt TRACe Y SCALe RLEVel OF FSet cceeeeeeeeeeeeeeeeeeeeeteneteteeeneees 199 VIN EAT Kn EE 200 INPUEATTENUAION ALTO a Ran 200 INGE EAE TA ME 201 INPUCEATT AUTO E 201 NPUCEATT STATO E 201 INPUECGAIN VAL ari A A elec nate nnn 202 INPUEGAINESTA TO ona 202 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance CALCulate lt n gt UNIT POWer lt Unit gt This command selects the unit of the y axis The unit applies to all measurement windows Parameters lt Unit gt DBM V A W DBPW WATT DBUV DBMV VOLT DBUA AMPere RST dBm Example CALC UNIT POW DBM Sets the power unit to dBm Manual operation See Unit on page 104 CONFigure POWer AUTO lt Mode gt This command is used to switch on or off automatic power level detection When switched on power level detection is performed at the start of each measurement sweep Parameters lt Mode gt ON OFF ONCE RST ON Manual operation See Setting the Reference Level Automatically Auto Level on page 105 CONFigure POWer EXPected RF lt Value gt This command specifies the mean power level of the source signal as supplied to the instrument s RF input This value is overwritten if Auto Level mode is turned on Parameters lt Value gt Default un
356. rements Table 5 4 Predefined settings for WLAN SEM measurements Setting Default value Number of ranges 3 Frequency Span 12 75 MHz Fast SEM OFF Sweep time 140 us RBW 30 kHz Power reference type Channel Power Tx Bandwidth 3 84 MHz Number of power classes 1 manually using the Standard Files softkey in the main SEMask menu The subdir ectory displayed in the SEM standard file selection dialog box depends on the standard you selected previously for the WLAN Modulation Accuracy Flatness measurement see Standard on page 91 CD You must select the SEM file with the pre defined settings required by the standard For further details about the Spectrum Emission Mask measurements refer to Spec trum Emission Mask Measurement in the R amp S FSW User Manual To restore adapted measurement parameters the following parameters are saved on exiting and are restored on re entering this measurement e Reference level and reference level offset e Sweep time e Span The main measurement menus for the frequency sweep measurements are identical to the Spectrum application 5 4 3 Occupied Bandwidth The Occupied Bandwidth measurement is performed as in the Spectrum application with default settings Table 5 5 Predefined settings for WLAN OBW measurements Setting Default value 96 Power Bandwidth 99 96 Channel bandwidth 3 84 MHz The Occupied Bandwidth measureme
357. resis eese nennen 206 TRIGger SEQuence E EB VelBBPUOWOL EE 206 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance TRIGger SEQuenceJ LEVel BBPower essssssseseseseeeee eese trennen nennen nens nnns 206 TRIGger SEQuence LEVE EX lerrnaleport ipeo ee aar nennt add 207 TRIGger SEQuence LEVelFPOWer 2 2 22 2 222r root titre casu seva 2 d EENS 207 TRIGSer SEQuence EV OP TEE 208 TRIGgerr SEOuesnce LEVelPOWGCGAU TO auderet trt reet nouae ex nct made eaa 208 TRiIGger SEQuence L EVelREBOWETF rri icit o 208 TRlGger ET e 209 TRlGoert GtOuencelGOUbce cece eaeaeaea aa narei aiiiar naaiden kradda aniei da 209 TRiGger SEQuence ME TEE 211 TRIGger SEQuence BBPower HOLDoff lt Period gt This command defines the holding time before the baseband power trigger event The command requires the Digital Baseband Interface R amp S FSW B17 or the Ana log Baseband Interface R amp S FSW B71 Note that this command is maintained for compatibility reasons only Use the TRIGger SEQuence IFPower HOLDoff on page 206 command for new remote control programs Parameters lt Period gt Range 150 ns to 1000s RST 150 ns Example TRIG SOUR BBP Sets the baseband power trigger source TRIG BBP HOLD 200 ns Sets the holding time to 200 ns TRIGger SEQuence DTIMe lt DropoutTime gt Defines the time the input signal must stay below the trigger level before
358. rpose bits GPO and GP1 are available as a Digital 1 Q trigger source The following table describes the assignment of the general purpose bits to the LVDS connector pins Table 5 2 Assignment of general purpose bits to LVDS connector pins Bit LVDS pin GPO SDATAA P Trigger1 GP1 SDATAM P Trigger2 GP2 SDATAO P Reserve1 GP3 SDATA4_P Reserve2 GP4 SDATAO P Marker1 GP5 SDATAA P Marker2 not available for Digital UO enhanced mode Remote command TRIG SOUR GPO see TRIGger SEQuence SOURce on page 209 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Trigger Level Mode Trigger Source Settings By default the optimum trigger level for power triggers is automatically measured and determined at the start of each sweep for Modulation Accuracy Flatness Tolerance measurements In order to define the trigger level manually switch to Manual mode Remote command TRIG SEQ LEV POW AUTO ON see TRIGger SEQuence LEVel POWer AUTO on page 208 Trigger Level Trigger Source Settings Defines the trigger level for the specified trigger source For details on supported trigger levels see the data sheet Remote command TRIGger SEQuence LEVel IFPower on page 207 TRIGger SEQuence LEVel IQPower on page 208 TRIGger SEQuence LEVel EXTernal port on page 207 For analog baseband B71 or digital baseband B17 input only TRIGger S
359. s EQUal command is set to true then this command specifies the exact number of data bytes a PPDU must have to take part in measurement analysis If the SENSe DEMod FORMat BANalyze DBYTes EQUal command is set to false this command specifies the minimum number of data bytes required for a PPDU to take part in measurement analysis Parameters lt NumDataBytes gt RST 1 Default unit bytes Manual operation See Min Max Payload Length IEEE 802 11b g DSSS on page 141 SENSe DEMod FORMat BANalyze DURation EQUal lt State gt For IEEE 802 11b and g DSSS signals only If enabled only PPDUs with a specific duration are considered for measurement analysis If disabled only PPDUs whose duration is within a specified range are considered The duration is specified by the SENSe DEMod FORMat BANalyze DURation MIN command A duration range is defined as a minimum and maximum duration the PPDU may have see SENSe DEMod FORMat BANalyze DURation MAX and SENSe DEMod FORMat BANalyze DURation MIN Parameters lt State gt ON OFF RST OFF Manual operation See Equal PPDU Length on page 140 SENSe DEMod FORMat BANalyze DURation MAX lt Duration gt For IEEE 802 11b and g DSSS signals only If the SENSe DEMod FORMat BANalyze DURation EQUal command is set to false this command specifies the maximum number of symbols allowed for a PPDU to take part in m
360. s command is identical to the LAYout REPLace WINDow com mand To add a new window use the LAYout NINDow 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 248 for a list of availa ble window types Selecting Items to Display in Result Summary The following command defines which items are displayed in the Result Summary Configuring the Result Display DISPlay WINDow lt n gt TABLe ITEM lt ltem gt lt State gt Defines which items are displayed in the Result Summary see Result Summary Detailed on page 40 and Result Summary Global on page 41 Note that the results are always calculated regardless of their visibility in the Result Summary Parameters Item Item to be included in Result Summary For an overview of pos sible results and the required parameters see the tables below State ON OFF ON Item is displayed in Result Summary OFF Item is not displayed in Result Summary RST ON Table 10 8 Parameters for the items of the Result Summary Detailed Result in table SCPI parameter TX channel Tx All TALL 1 Q offset IOFSset Gain imbalance GIMBalance Quadrature offset QOFFset UO skew IQSKew PPDU power TPPower Crest factor TCFactor Receive channel Rx All RALL PPDU power RPPower Crest factor RCFactor Bitstream Stream All SALL
361. s ready to trigger The trigger signal can be output by the R amp S FSW automatically or manually by the user If it is sent automatically a high signal is output when the R amp S FSW has trig gered due to a sweep start Device Triggered or when the R amp S FSW is ready to receive a trigger signal after a sweep start Trigger Armed Manual triggering If the trigger output signal is initiated manually the length and level high low of the trigger pulse is also user definable Note however that the trigger 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 O Providing trigger signals as output is described in detail in the R amp S FSW User Manual 4 8 Preparing the R amp S FSW for the Expected Input Signal Frontend Parameters On the R amp S FSW the input data can only be processed optimally if the hardware set tings match the signal characteristics as closely as possible On the other hand the hardware must be protected from powers or frequencies that exceed the allowed limits Therefore you must set the hardware so that it is optimally prepared for the expected input signal without being overloaded You do this using the frontend parameters Consider the following recommendations Reference level Adapt the R amp S FSW s hardware
362. s single sequence mode so each active measurement will be performed once INIT SEQ IMM Starts the sequential measurements Usage Event Manual operation See Sequencer State on page 86 INITiate SEQuencer MODE lt Mode gt This command selects the way the R amp S FSW application performs measurements sequentially Before this command can be executed the Sequencer must be activated see SYSTem SEQuencer on page 261 A detailed programming example is provided in the Operating Modes chapter in the R amp S FSW 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 FSW User Manual 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 channels 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
363. sed Qu Nused EVM vs Carrier Three trace types are provided for this evaluation Table 10 14 Query parameter and results for EVM vs Carrier TRACE1 The minimum EVM value over the analyzed PPDUS for each of the N sey subcarriers TRACE2 The average EVM value over the analyzed PPDUS for each of the Nausea subcarriers TRACES The maximum EVM value over the analyzed PPDUS for each of the Nusea subcarriers Each EVM value is returned as a floating point number expressed in units of dB Supported data formats see FORMat DATA on page 276 ASCii UINT Example For EVM n the EVM of the m th analyzed PPDU for the subcarrier n 1 2 Nusea TRACE1 Minimum EVM value per subcarrier Minimum EVM 1 EVM31 EVMstatistic Length 1 Minimum EVM value for subcarrier Nuseq 1 2 Minimum EVM 2 EVM 7 EVMstatistic Length 2 H Minimum EVM value for subcarrier Nuseq 1 2 1 Minimum EVM nused EVMo nused peas EVMsgatistic Length Nused H Minimum EVM value for subcarrier N seg 1 2 Error vs Preamble Three traces types are available with this measurement The basic trace types show either the minimum mean or maximum frequency or phase value as measured over the preamble part of the PPDU Supported data formats see FORMat DATA on page 276 ASCii REAL 10 9 4 10 10 9 4 11 10 9 4 12 Retrieving Results FFT Spectrum Returns the power vs frequency values obtained
364. sidered by a sub sequent TRACe lt n gt DATA query for EVM vs Symbol and EVM vs Carrier result displays OFF EVM vs Symbol result display query returns all detected PPDUS in the current capture buffer EVM vs Carrier result display query returns the statistical results for all analyzed PPDUs RST OFF Example LAY WIND2 REPL EVSY SENS BURS SEL STAT ON SENS BURS SEL 10 TRAC2 DATA TRACE1 Returns the trace results for the PPDU number 10 in window 2 EVM vs Symbol TRACe lt n gt DATA lt ResultType gt This command queries current trace data and measurement results from the window previously selected using DISPlay WINDowcn SELect Retrieving Results As opposed to the R amp S FSW base unit the window suffix lt n gt is not considered in the R amp S FSW WLAN application Use the DISPlay WINDow lt n gt SELect to select the window before you query trace results For details see chapter 10 9 4 Measurement Results for TRACe lt n gt DATA TRACE lt n gt on page 279 Suffix lt n gt irrelevant Parameters lt ResultType gt Selects the type of result to be returned TRACE1 TRACE6 Returns the trace data for the corresponding trace Note that for the default WLAN I Q measurement Modulation Accuracy Flatness and Tolerance only 1 trace per window TRACE is available LIST Returns the results of the peak list evaluation for Spectrum Emiss
365. ssumed DataFilename Contains the filename of the UO 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 e lt xyz gt 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 int64 see DataType element Examples e xyz complex 1ch float32 e xyz polar 1ch floato4 e xyzreal 1ch int16 e 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 UO data The preview data is determined by the routine that saves an iq tar file e g R amp S FSW 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 IqTar 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
366. surement Modulation Accuracy Flatness and Tolerance Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance The following commands are required to configure the WLAN IQ measurement descri bed in chapter 3 1 WLAN I Q Measurement Modulation Accuracy Flatness and Tol erance on page 13 Signal STE Configuring the Data Input and EE Frontend Configuration cscri IG MAG AP Tute EE Synchronization and OFDM Demodulation esee Tracking and Channel Estima ovina prse t n Ev luation RANGO geckegen tee deen tieeieceeeeied spent A AUTOMAIO SQUINGS E M WCEP le Signal Description The signal description provides information on the expected input signal Useful commands for describing the WLAN signal described elsewhere e SENSe FREQuency CENTer on page 196 Remote commands exclusive to describing the WLAN signal CON Fig ite EE CALGulateLIMIETOLeT SI B vss bad ona vecta ee a sa ata CONFigure STANdard Standard This remote control command specifies which WLAN standard the option is configured to measure The availability of many commands depends on the selected standard Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 10 5 2 Parameters lt Standard gt 0 IEEE 802 11a 1 IEEE
367. t e Q skew ps e PPDU power dBm e Crest factor dB Receive channel Rx All e PPDU power dBm e Crest factor dB Bitstream Stream All e Pilot bit error rate e EVM all carriers dB e EVM data carriers dB e EVM pilot carriers dB For details on the individual parameters and the summarized values see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 13 Remote command LAY ADD 1 RIGH RSD see LAYout ADD WINDow on page 248 User Manual 1173 9357 02 11 40 R amp S FSW K91 Measurements and Result Displays EH Result Summary Global The global result summary provides measurement results based on the complete sig nal consisting of all channels and streams The observation length is the number of PPDUS to be analyzed as defined by the Evaluation Range gt Statistics settings In contrast the detailed result summary provides results for each individual channel and stream For MIMO measurements IEEE 802 1 1ac n the global result summary provides the results for all data streams whereas the detailed result summary provides the results for individiual streams immary Global Recognized cal Channel 18 Limit Limit Fig 3 24 Global result summary for IEEE 802 11a g OFDM ac n p standards SSS ee EE S URS User Manual 1173 9357 02 11 41 R amp S FSW K91 Measurements and Result Displays 1 Result Summary Global No of PPDUs
368. t use compensation 3 1 1 6 RF Carrier Suppression IEEE 802 11b g DSSS Standard definition The RF carrier suppression measured at the channel center frequency shall be at least 15 dB below the peak SIN x x power spectrum The RF carrier suppression shall be measured while transmitting a repetitive 01 data sequence with the scrambler disa bled using DQPSK modulation A 100 kHz resolution bandwidth shall be used to per form this measurement Comparison to IQ offset measurement in the R amp S FSW WLAN application The IQ offset measurement in the R amp S FSW WLAN application returns the current car rier feedthrough normalized to the mean power at the symbol timings This measure ment does not require a special test signal and is independent of the transmit filter shape 3 1 1 7 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance The RF carrier suppression measured according to the standard is inversely propor tional to the IQ offset measured in the R amp S FSW WLAN application The difference in dB between the two values depends on the transmit filter shape and should be deter mined with a reference measurement The following table lists the difference exemplarily for three transmit filter shapes 0 5 dB Transmit filter Q Offset dB RF Carrier Suppression dB Rectangular 11 dB Root raised cosine a 0 3 10 dB Gaussian a 0 3 9 dB EVM Measurement The R amp S
369. ta 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 Remote command SENSe FREQuency OFFSet on page 198 5 3 4 4 Amplitude Settings Amplitude settings determine how the R amp S FSW must process or display the expected input power levels To configure the amplitude settings Amplitude settings can be configured via the AMPT key or in the Amplitude dialog box gt To display the Amplitude dialog box do one of the following e Select Input Frontend from the Overview and then switch to the Amplitude tab e Select the AMPT key and then the Amplitude Config softkey WLAN IQ Measurement Modulation Accuracy Flatness Tolerance mm ge Amplitude Scale Reference Level Input Settings Mode Manual Preamplifier Reference Lvl Signal Lvi RMS 10 0 dBm e Input Coupling Offset 0 0 dB Unit Impedance RF Attenuation Electronic Attenuation State Mode Mode 110 0 dB Value Reference Level Settings tee eer e dte x aA KENEEN E EE AR
370. tch platform For details read the OSP operation manual An online keyboard is displayed to enter the address in dotted IPV4 format Tip the LED symbol indicates the state of the OSP switch box Color State gray OSP switch box off or IP address not available valid red OSP switch box on and IP address valid but not accessible green OSP switch box on and IP address accessible Remote command CONFigure WLAN MIMO OSP ADDRess on page 216 OSP Switch Bank Configuration Sequential Using OSP Switch Setup The R amp SGOSP B101 option is fitted in one of the three module slots switch banks at the rear of the OSP switch platform The DUT Tx antennas are connected with the analyzer via the R amp S OSP B101 module fitted in the OSP switch platform Select the R amp SGOSP B101 module that is used for this connection Remote command CONFigure WLAN MIMO OSP MODule on page 216 Manual Sequential MIMO Data Capture Note For sequential MIMO measurements the DUT has to transmit identical PPDUs over time The signal field for example has to be identical for all PPDUs For details see chapter 4 3 4 1 Sequential MIMO Measurement on page 72 For this MIMO method you must connect each Tx antenna of the WLAN DUT with the analyzer and start data capturing manually see chapter 5 3 12 Sweep Settings on page 146 The dialog box shows a preview of the capture memories one for each RX antenna The PPDUS detected by the ap
371. terest Remote command SENSe BANDwidth RESolution FILTer STATe on page 203 Trigger Settings Trigger settings determine when the R amp S FSW starts to capture the input signal Trigger settings can be configured via the TRIG key or in the Trigger dialog box which is displayed when you select the Trigger button in the Overview Signal Capture Trigger Source Trigger In Out MIMO Capture Trigger Source FS Z11 Trigger off on Connection Guideline for Trigger Unit FS Z11 Level Mode DUT Master Analyzer RF OUTPUT 1 RF INPUT NOISE SOURCE OUTPUT TRIGGER INPUT Trigger Level sz p RF OUTPUT 3 Slave Analyzer 1 RF OUTPUT 4 RF INPUT Trigger Offset ar TRIGGER INPUT Slave Analyzer 2 Drop Out Time RF INPUT TRIG INPUT TRIG Our TRIGGER INPUT TRIG OUT J 5 TRIG MANUAL Slave Analyzer 3 Slope Rising a S vr INPUT NOISE SOURCE TRIG OUl4 H ES TRIGGER INPUT Holdoff Cable Trigger Cable Trigger Optional DUT with TRIGGER OUTPUT Hysteresis Cable RF External triggers from one of the TRIGGER INPUT OUTPUT connectors on the R amp S FSW are configured in a separate tab of the dialog box WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Trigger Source Trigger In Out Trigger 2 e Output Output Type User Defined E Low Pulse Length 100 0 us Send Trigger It Trigger 3 Input Output For more information on trigger settings and step by step instructions on configuring trigger
372. ters on page 13 Usage Query only FETCh BURSt SYMBolerror AVERage FETCh BURSt SYMBolerror MAXimum FETCh BURSt SYMBolerror MINimum This command returns the average maximum or minimum percentage of symbols that were outside the allowed demodulation range within a PPDU For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only UNIT EVM lt Unit gt This command specifies the units for EVM limits and results see chapter 3 1 1 Modu lation Accuracy Flatness and Tolerance Parameters on page 13 Parameters lt Unit gt DB PCT RST DB UNIT GIMBalance lt Unit gt This command specifies the units for gain imbalance results see chapter 3 1 1 Modu lation Accuracy Flatness and Tolerance Parameters on page 13 10 9 1 3 Retrieving Results Parameters lt Unit gt DB PCT RST DB Limit Check Results The following commands are required to query the results of the limit checks Useful commands for retrieving results described elsewhere e UNIT EVM on page 268 e UNIT GIMBalance on page 268 Remote commands exclusive to retrieving limit check results e E LIMI Tee 269 CALCulate LIMit BURSt EVM ALL AVERage RE Gu 269 CAL Culate LIMI DBURGCEVM ALL M AximumRESGur eese eese enne 269 CALCulate LIMit BURStEVM DATA AVERage RESUIt sse 270 CALOulate LIMit BURSt EVM DATA MAXimum RESUIt
373. tes more accurate mea surement results 9 2 Error Messages and Warnings The following messages are displayed in the status bar in case of errors Results contribute to overall results despite inconsistencies Info Comparison between HT SIG Payload Length and Estimated Payload Length not performed due to insufficient SNR The R amp S FSW K91 application compares the HT SIG length against the length estima ted from the PPDU power profile If the two values do not match the corresponding entry is highlighted orange If the signal quality is very bad this comparison is sup pressed and the message above is shown Warning HT SIG of PPDU was not evaluated Decoding of the HT SIG was not possible because there was to not enough data in the Capture Memory potential PPDU truncation Warning Mismatch between HT SIG and estimated SNR Power PPDU length The HT SIG length and the length estimated by the R amp S FSW application from the PPDU power profile are different User Manual 1173 9357 02 11 165 Error Messages and Warnings Warning Physical Channel estimation impossible Phy Chan results not availa ble Possible reasons channel matrix not square or singular to working preci sion The Physical Channel results could not be calculated for one or both of the following reasons e The spatial mapping can not be applied due to a rectangular mapping matrix the number of space time streams is not equal to the nu
374. tes to an analysis of each corresponding sample within each processed PPDU For PVT Rising and PVT Falling displays the results are restricted to the rising or fall ing edge of the analyzed PPDUs 10 9 4 13 10 9 4 14 10 9 5 Retrieving Results The type of PVT data returned is determined by the TRACE number passed as an argument to the SCPI command TRACE1 minimum PPDU data values TRACE2 mean PPDU data values TRACE3 maximum PPDU data values Supported data formats see FORMat DATA on page 276 ASCii REAL Signal Field The bits are returned as read from the corresponding signal field parts in transmit order Le the first transmitted bit has the highest significance and the last transmitted bit has the lowest significance See also Signal Field on page 43 The TRAC DATA command returns the information as read from the signal field for each analyzed PPDU The signal field bit sequence is converted to an equivalent sequence of hexadecimal digits for each analyzed PPDU in transmit order Spectrum Flatness The spectrum flatness evaluation returns absolute power values per carrier Two trace types are provided for this evaluation Table 10 15 Query parameter and results for Spectrum Flatness TRACE1 All spectrum flatness values per channel TRACE2 An average spectrum flatness value for each of the 53 or 57 117 within the IEEE 802 11 n standard carriers Absolute power resul
375. th lt PeakFreq gt frequency of the peak in a range lt PowerAbs gt absolute power of the peak in dBm lt PowerRel gt power of the peak in relation to the channel power in dBc lt PowerDelta gt distance from the peak to the limit line in dB positive values indicate a failed limit check lt LimitCheck gt state of the limit check 0 PASS 1 FAIL e lt Unused1 gt lt Unused2 gt reserved 0 0 Retrieving Results TRACe lt n gt DATA X lt TraceNumber gt This command queries the horizontal trace data for each sweep point in the specified window for example the frequency in frequency domain or the time in time domain measurements This is especially useful for traces with non equidistant x values e g for SEM or Spuri ous Emissions measurements Query parameters lt TraceNumber gt Trace number TRACE1 TRACE6 Example TRAC3 X TRACE1 Returns the x values for trace 1 in window 3 Usage Query only TRACe IQ DATA MEMory lt OffsetSamp gt lt NumSamples gt Returns all the UO trace data in the capture buffer The result values are scaled in Volts The command returns a comma separated list of the measured voltage values in floating point format Comma Separated Values CSV The number of values returned is 2 the number of complex samples the first half being the values the second half the Q values The total number of complex samples is displayed in the channel bar in manual oper
376. 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 Contains the number of samples of the UO data For multi channel signals all chan nels have the same number of samples One sample can be e A complex number represented as a pair of and Q values e A complex number represented as a pair of magnitude and phase values e Areal number represented as a single real value See also Format element Clock Contains the clock frequency in Hz i e the sample rate of the I Q data A signal gen erator typically outputs the UO data at a rate that equals the clock frequency If the 1 Q 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 UO 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 and Q are unitless real Realnumber unitless e polar Complex number in polar format i e magnitude u
377. the R amp S FSW on a parallel channel to clear all currently active remote channels Depend ing on the used interface and protocol send the following commands e Visa viClear e GPIB ibcir e RSIB RSDLLibclr 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 SCPI confirmed CALCulate n BURSt IMMediate This command forces the IQ measurement results to be recalculated according to the current settings Manual operation See Calc Results on page 120 INITiate CONTinuous State This command controls the sweep mode Note that in single sweep mode you can synchronize to the end of the measurement with OPC OPC or WAI In continuous sweep mode synchronization to the end of the measurement is not possible Thus it is not recommended that you use continuous Sweep mode in remote control as results like trace data or markers are only valid after a single sweep end synchronization For details on synchronization see the Remote Basics chapter in the R amp S FSW User Manual If the sweep mode is changed for a measurement channel while the Sequencer is active see INITiate SEQuencer IMMediate on page 259 the mode is only con sidered the next time the measurem
378. the WLAN IQ measurement are described here Note that the CONF BURS lt ResultType gt IMM commands change the screen layout to display the Magnitude Capture buffer in window 1 at the top of the screen and the selected result type in window 2 below that Any other active windows are closed Use the LAYout commands to change the display see chapter 10 7 Configuring the Result Display on page 247 e Selecting the WLAN IQ Measurement Modulation Accuracy Flatness and Toler clo TT 177 e Selecting a Common RF Measurement for WLAN Gionals 183 10 4 1 Selecting the WLAN IQ Measurement Modulation Accuracy Flat ness and Tolerance Any of the following commands can be used to return to the WLAN IQ measurement Each of these results are automatically determined when the WLAN IQ measurement is performed Selecting a Measurement 0 The selected measurement must be started explicitely see chapter 10 8 Starting a Measurement on page 257 CONFloure BURG AM AM IMMedlatel nene enne tnn 178 CONFigure BURStAM EVM IMMediate cesses nennen 178 CONFigure BURSEAM PMEIMMbediate a enii asiaa eet nete aenea noun 178 CONFigure BURSt CONSt CCARrier IMMediate ecce 179 CONFloure BURGCCONSt CSvMboltlMMedatel nennen 179 CONFloure BURGCEVM EC Aert IMMediatel nana nnnnnnnnnnnnncnnnn 179 CONFigure BURSt EVM ESYMbol MMediate IEEE 802 11b and g DSesn 179 CONFloure BURGCEVM ECH IMMediatel nenne
379. the 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 use the LAYout CATalog WINDow query lt WindowType gt Type of result display you want to use in the existing window See LAYout ADD WINDow on page 248 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 As opposed to the DISPlay WINDow lt n gt SIZE on page 247 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 x 0 y 0 x 100 Fig 10 1 SmartGrid coordinates for remote control of the splitters Parameters Index1 The index of one window the splitter controls lt Index2 gt The index of a window on the other side of the splitter E User Manual 1173 9357 02 11 252 Configuring the Result Display lt Position gt New vertical or horizontal position o
380. the number of PPDUs that can be captured in one buffer this command only returns the lengths of the PPDUs in the current capture buffer The result is a comma separated list of lengths one for each PPDU Return values lt PPDULength gt Length of the PPDU in the unit specified by the UNIT BURSt command Usage Query only FETCh BURSt STARts This command returns the start position of each analyzed PPDU in the current capture buffer Return values lt Position gt Comma separated list of samples or symbols depending on the UNIT BURSt command indicating the start position of each PPDU Usage Query only UNIT BURSt Unit This command specifies the units for PPDU length results see FETCh BURSt LENGths on page 263 10 9 1 2 Retrieving Results Parameters lt Unit gt SYMBol SAMPle RST SYMBol Error Parameter Results The following commands are required to retrieve individual results from the WLAN IQ measurement on the captured l Q data see chapter 3 1 1 Modulation Accuracy Flat ness and Tolerance Parameters on page 13 FETOTBURSCALE E D eR 265 e Bel E e EM KEEN 265 FETCHIBURStCRE SEMA XIN KE 265 FETCH ee eg le Tra EE 265 FETChHBURSEEVIVIAL AVERAGE cuida Aik nenas 265 FETCH BURSEEVNEALLMAXIMUDO ii ad De Ca nara nva 265 FETCHEBURStEVM ALL MINIMUM iid irc ict reae criada Ye aa ieas 265 EETCDI BURSEEVMEDATACAVERG OQGT EE 266 FETCH BURSEEVM DATAMAX
381. the results of specific measurement functions in a table for numerical evaluation The contents of the result summary vary depending on the selected measurement function See the description of the individual measurement functions for details 2 Result Summary Channel Bandwidth Power TX1 Ref 1 229 MHz 0 86 dBm 0 86 dBm ower Upper 79 59 dB 80 34 dB 85 04 dB 83 85 dB Remote command LAY ADD 1 RIGH RSUM see LAYout ADD WINDow on page 248 Marker Table Displays a table with the current marker values for the active markers Stimulus Response Function T Function Result Remote command LAY ADD 1 RIGH MTAB see LAYout ADD WINDow on page 248 Results CALCulate n MARKercm X on page 275 CALCulate lt n gt MARKer lt m gt Y on page 290 Marker Peak List The marker peak list determines the frequencies and levels of peaks in the spectrum or time domain How many peaks are displayed can be defined as well as the sort order In addition the detected peaks can be indicated in the diagram The peak list can also be exported to a file for analysis in an external application User Manual 1173 9357 02 11 52 R amp S FSW K91 Measurements and Result Displays 2 Marker Peak List No l Remote command LAY ADD 1 RIGH PEAK see LAYout ADD WINDow on page 248 Results CALCulate lt n gt MARKer lt m gt X on page 275 CALCulate lt n gt MARKer lt m gt Y on page 290 User Manual
382. tion Parameters Logical Filters on page 77 Others may be dismissed because they contain too many or too few payload symbols as defined by the user or due to other irregularities or inconsis tency Dismissed PPDUs are indicated as such in the Signal Field result display highlighted red with a reason for dismissal PPDUs with detected inconsistencies are indicated by orange highlighting and a warn ing in the Signal Field result display but are nevertheless analyzed and included in statistical and global evaluations The remaining correct PPDUs are highlighted green in the Magnitude Capture buffer and Signal Field result displays and analyzed according to the current user settings Example The evaluation range is configured to take the Source of Payload Length from the signal field If the power period detected for a PPDU deviates from the PPDU length coded in the signal field a warning is assigned to this PPDU The decoded signal field length is used to analyze the PPDU The decoded and measured PPDU length together with the apropriate information is shown in the Signal Field result display Demodulation Parameters Logical Filters 4 6 Demodulation Parameters Logical Filters The demodulation settings define which PPDUs are to be analyzed thus they define a logical filter They can either be defined using specific values or according to the first measured PPDU Which of the WLAN demodulation parameter valu
383. tion is shown in figure 4 1 First the RF signal is downconverted to the IF frequency fic The resulting IF signal reit is shown on the left hand side of the figure After bandpass filtering the signal is sam pled by an analog to digital converter ADC at a sample rate of f This digital Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM sequence is resampled Thus the sample rate of the downsampled sequence r i is the Nyquist rate of f 20 MHz Up to this point the digital part is implemented in an ASIC 20MHz t 2 5 Ese o p S 8 EE E E E L E e o Ej Q E E x 8 i a SE 3 d gt 3 8 Jg a 09 7 os c 2 E Yo e E 2 5 8 5 a li a o 3 ez E B oc 2 c EE o o SIN QA Fig 4 1 Block diagram for the R amp S FSW WLAN application using the IEEE 802 11a or y OFDM standard In the lower part of the figure the subsequent digital signal processing is shown R amp S FSW K91 Measurement Basics _ _ _ a ee ee ee Packet search and timing detection In the first block the packet search is performed This block detects the Jong symbol LS and recovers the timing The coarse timing is detected first This search is imple mented in the time domain The algorithm is based on cyclic repetition within the LS after N 64 samples Numerous treatises exist on this subject e g 1 to 3 Further
384. tive white Gaussian noise AWGN 56 Adjacent channel leakage ratio SOC ACER M 48 Adjacent channels FRING THINGS OUN eege a eegene 108 203 AM AM PolymOMial degree ern rrr cer tras 144 Result displays Trace E VE AM EVM Results stores 24 le Le EE 283 AM PM sesult CIS DAY Srita gegen ege 23 Trace E EE 283 Amplitude Configuration remote Configuration softkey fuper M s Analog Baseband le Oe 97 Analog Baseband B71 VOMOdE cedida ne TERE EENEN 97 Input type remote control cooooccncncnncocninccncnnnncancnns 193 Analog Baseband Interface B71 ln e 97 Analysis Bandwidth definition cconooocccnnnccnocooccnccncnanonono 307 Remote control FRE measurements eere rra tero ir EEN 151 E P ates 151 Antennas Assignment MIMO sse 117 Mapping MIMO a 139 MIMO settings 16 OSP switch box ses State MIMO eer rca 117 Applications AQOpted parameters cosmetica 87 Ej leno EE 87 Attenuation 105 Auto 105 DetaUll 88 mieux taladrar 105 Manual M 105 Option B25 105 diez P 78 Protective remote ceceeeeeceeseseeeeeeseeeeeeeeeeeeeaes 186 Auto level Hysteresis iet iere EES Reference level Softkey SR AUTO LEVEI EE Auto E E Meastim
385. tness and Group Delay results can be based on either the effective channels or the physical channels While the physical channels cannot always be determined the effective channel can always be estimated from the known training fields Thus for some PPDUs or mea surement scenarios only the results based on the mapping of the space time stream to the Rx antenna effective channel are available as the mapping of the Rx antennas to the Tx antennas physical channel could not be determined For more information see chapter 4 3 3 Physical vs Effective Channels on page 70 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Spectrum Flatness STEIN Effective Channel B Saad 3 Spectrum Flatness Remote command CONFigure BURSt SPECtrum FLATness CSELect on page 256 5 3 10 3 AM AM Configuration For AM AM result displays the trace is determined by calculating a polynomial regres sion model for the scattered measurement vs reference signal data see AM AM on page 23 The degree of this model can be specified in the Result Config dialog box for this result display 302 11a Capt sts DOl AM AM Polynomial degree for curve fitting The resulting regression polynomial is indicated in the window title of the result display Remote command CONFigure BURSt AM AM POLYnomial on page 256 Resulting coefficients CONFigure BURSt AM AM COEFficients on page 257 5 3 11 W
386. to 3 GHz This filter is used to remove the harmonics of the R amp S FSW in order to mea sure the harmonics for a DUT for example This function requires option R amp S FSW B13 Note for RF input signals outside the specified range the high pass filter has no effect For signals with a frequency of approximately 4 GHz upwards the harmonics are suppressed sufficiently by the YIG filter Remote command INPut FILTer HPASs STATe on page 186 YIG Preselector Activates or deactivates the YIG preselector An internal YIG preselector at the input of the R amp S FSW ensures that image frequen cies are rejected However the YIG filter may limit the bandwidth of the UO data and will add some magnitude and phase distortions You can check the impact in the Spec trum Flatness and Group Delay result displays Note that the YIG preselector is active only on frequencies greater than 8 GHz There fore switching the YIG preselector on or off has no effect if the frequency is below that value Remote command INPut FILTer YIG STATe on page 187 Digital UO Input Settings The following settings and functions are available to provide input via the Digital Base band Interface R amp S FSW B17 in the applications that support it They can be configured via the INPUT OUTPUT key in the Input dialog box WLAN IQ Measurement Modulation Accuracy Flatness Tolerance bast Input Source Power Sensor Frequency Digital IQ Input
387. to replace or delete the channels Activating WLAN Measurements 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 SANALYZER Spectrum Usage Query only Table 10 3 Available measurement channel types and default channel names in Signal and Spectrum Analyzer mode Application lt ChannelType gt Parameter Default Channel Name Spectrum SANALYZER Spectrum 1 Q Analyzer IQ IQ Analyzer Pulse R amp S FSW K6 Pulse Analog Demodulation Analog Demod R amp S FSW K7 GSM R amp S FSW K10 GSM Multi Carrier Group Delay MCGD MC Group Delay R amp S FSW K17 Noise R amp S FSW K30 NOISE Noise Phase Noise R amp S FSW PNOISE Phase Noise K40 Transient Analysis Transient Analysis R amp S FSW K60 VSA R amp S FSW K70 VSA 3GPP FDD BTS 3G FDD BTS R amp S FSW K72 3GPP FDD UE R amp S FSW 3G FDD UE K73 TD SCDMA BTS TD SCDMA BTS R amp S FSW K76 TD SCDMA UE TD SCDMA UE R amp S FSW K77 cdma2000 BTS CDMA2000 BTS R amp S FSW K82 cdma2000 MS R amp S FSW CDMA2000 MS K83 Note the default channel name is also listed in the table If the specified name for a new channel already
388. to level OVERIoad This bit is set if a signal overload is detected when an auto level measurement is performed 6 Auto level NoSIGnal This bit is set if no signal is detected by the auto level measurement 7 14 These bits are not used 15 This bit is always 0 10 11 2 STATus QUEStionable DIQ Register This register contains information about the state of the digital UO input and output This register is available with option Digital Baseband Interface R amp S FSW B17 Digital Baseband Interface R amp S FSW B17 The status of the STATus QUESTionable DIO register is indicated in bit 14 of the STATus QUESTionable register You can read out the state of the register with STATus QUEStionable DIO CONDition on page 295 and STATus QUEStionable DIQ EVENt on page 297 Bit No Meaning 0 Digital UO Input Device connected This bit is set if a device is recognized and connected to the Digital Baseband Interface of the analyzer 1 Digital UO Input Connection Protocol in progress This bit is set while the connection between analyzer and digital baseband data signal source e g R amp S SMU R amp S Ex I Q Box is established 2 Digital UO Input Connection Protocol error This bit is set if an error occurred during establishing of the connect between analyzer and digital UO data signal source e g R amp S SMU R amp S Ex 1 Q Box is established Status Registers Bit No Mean
389. trigger sources The range of the value is between 3 dB and 50 dB with a step width of 1 dB For more information see chapter 4 9 2 Trigger Hysteresis on page 81 Remote command TRIGger SEQuence IFPower HYSTeresis on page 206 Trigger Holdoff Trigger Source Settings Defines the minimum time in seconds that must pass between two trigger events Trigger events that occur during the holdoff time are ignored For more information see chapter 4 9 4 Trigger Holdoff on page 82 Remote command TRIGger SEQuence IFPower HOLDoff on page 206 Slope Trigger Source Settings For all trigger sources except time and frequency mask Realtime only you can define whether triggering occurs when the signal rises to the trigger level or falls down to it Remote command TRIGger SEQuence SLOPe on page 209 FS Z11 Trigger Trigger Source Settings If activated the measurement is triggered by a connected R amp S FS Z11 trigger unit simultaneously for all connected analyzers This is useful for MIMO measurements in simultaneous measurement mode see Simultaneous Signal Capture Setup on page 117 The Trigger Source is automatically set to External Trigger 1 2 3 The required connec tions between the analyzers the trigger unit and the DUT are indicated in the graphic For details see chapter 4 9 5 Trigger Synchronization Using an R amp S FS Z11 Trigger Unit on page 83 Remote command TRIGger SEQuence SO
390. ts are returned in dB Supported data formats FORMat DATA ASCii REAL Importing and Exporting UO Data and Results The I Q data to be evaluated in the WLAN application can not only be measured by the WLAN application itself it can also be imported to the application provided it has the correct format Furthermore the evaluated UO data from the WLAN application can be exported for further analysis in external applications For details on importing and exporting UO data see the R amp S FSW User Manual TEE e Date ene KE 288 MMEMon STObRelO State 289 MMEMory LOAD IQ STATe 1 lt FileName gt This command restores UO data from a file Analysis The file extension is iqw Parameters lt FileName gt String containing the path and name of the source file Example MMEM LOAD IQ STAT 1 C R_S Instr user data iqw Loads IQ data from the specified file Usage Setting only Manual operation See 1 Q Import on page 153 MMEMory STORe IQ STATe 1 lt FileName gt This command writes the captured UO data to a file 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 exter
391. ts must be respected i e iq tar uses an ordered XML schema For your own implementation of the ig tar file format make sure to validate your XML file against the given schema The following example shows an UO parameter XML file The XML elements and attrib utes are explained in the following sections Sample UO parameter XML file xyz xml xml version 1 0 encoding UTF 8 g xml stylesheet type text xsl href open IqTar xml file in web browser xslt RS IQ TAR FileFormat fileFormatVersion 1 xsi noNamespaceSchemaLocation RsIqTar xsd xmlns xsi http www w3 org 2001 XMLSchema instance gt lt Name gt FSV K10 lt Name gt lt Comment gt Here is a comment lt Comment gt lt DateTime gt 2011 01 24T14 02 49 lt DateTime gt 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 lt DataType gt float32 lt DataType gt lt ScalingFactor unit V gt 1 lt ScalingFactor gt lt NumberOfChannels gt 1 lt NumberOfChannels gt lt DataFilename gt xyz complex float32 lt DataFilename gt lt UserData gt 1 Q Data File Format iq tar lt UserDefinedElement gt Example lt UserDefinedElement gt lt UserData gt lt PreviewData gt lt PreviewData gt lt RS_IQ TAR FileFormat gt Element Description RS_IQ_TAR_File Format The root element of the XML file It must contain the attribute fileFormatVersion
392. u 2 luust Qu st e Pilots Only CONFigure BURSt CONStellation CARRier SELect PILOTS Nsp pairs of and Q data per OFDM Symbol in the natural number order OFDM Symbol 1 l 1 Q 4 I1 2 Q1 2 Uh ve Q1 Nsp OFDM Symbol 2 121 Q21 122 Q2 la Nsp Q2 Nsp OFDM Symbol N Ins Qui In 2 Qu 2 IN Nsp Qu sp e Single carrier 1 pair of and Q data per OFDM Symbol for the selected carrier CONFigure BURSt CONStellation CARRier SELect k with ke t Nusea 1 2 um Nusea 1 2 JL Nused E 1 2 OFDM Symbol 1 l4 4 Q 1 OFDM Symbol 2 l2 1 Q21 OFDM Symbol N ln 1 Qu 1 10 9 4 7 Constellation vs Carrier This measurement represents the complex constellation points as and Q data See for example IEEE Std 802 11 2012 Fig 18 10 BPSK QPSK 16 QAM and 64 QAM constellation bit encoding Each and Q point is returned in floating point format Data is returned as a repeating array of interleaved and Q data in groups of N seg subcarri ers per OFDM Symbol until all the and Q data for the analyzed OFDM Symbols is exhausted 10 9 4 8 10 9 4 9 Retrieving Results Note that as opposed to the Constellation results the DC null subcarriers are included as NaNs Nusea Pairs of and Q data per OFDM Symbol OFDM Symbol 1 11 4 Q4 4 h2 Q12 Fi vuse Q1 Nusea OFDM Symbol 2 I 4 Qz 1 I22 Q2 2 l2 Nuse Q2Nused OFDM Symbol N Ini Qu Ino Qu 2 IN Nu
393. uadrature offset gt lt max quadrature offset gt lt min EVM all bursts gt lt average EVM all bursts gt lt max EVM all bursts gt lt min EVM data carriers gt lt average EVM data carriers gt lt max EVM data carriers gt lt min EVM pilots gt lt average EVM pilots gt lt max EVM pilots gt lt min IQ skew gt lt average IQ skew gt lt max IQ skew gt FETCh BURSt CRESt AVERage FETCh BURSt CRESt MAXimum FETCh BURSt CRESt MINimum This command returns the average maximum or minimum determined CREST factor ratio of peak power to average power in dB For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only FETCh BURSt EVM ALL AVERage FETCh BURSt EVM ALL MAXimum FETCh BURSt EVM ALL MINimum This command returns the average maximum or minimum EVM in dB This is a com bined figure that represents the pilot data and the free carrier Retrieving Results For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only FETCh BURSt EVM DATA AVERage FETCh BURSt EVM DATA MAXimum FETCh BURSt EVM DATA MINimum This command returns the average maximum or minimum EVM for the data carrier in dB For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 13 Usage Query only FETCh BURSt EVM PILot AVERage FETCh BURSt EVM PILot MAXimum F
394. ual operation See Lower Level Hysteresis on page 146 SENSe ADJust CONFigure HYSTeresis UPPer Threshold When the reference level is adjusted automatically using the SENSe ADJust LEVel on page 244 command 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 measurement before the reference level is adapted automatically Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Threshold gt Range 0 dB to 200 dB RST 1 dB 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 145 SENSe ADJust LEVel This command initiates a single internal measurement that evaluates and sets the ideal reference level for the current input data and measurement settings 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 FSW or limiting the dynamic range by an S N ratio that is too small Example ADJ LEV Usage Event Manual operation See Setting the Reference Level Automatically Auto
395. um of 201 data points is returned fol lowing a data count value The first value in the return data represents the quantity of probability values that follow Each of the potential 201 data points is returned as a probability value and represents the total number of samples that are equal to or exceed the current mean power level Probability data is returned up to the power level that contains at least one sample It is highly unlikely that the full 201 data values will ever be returned Each probability value is returned as a floating point number with a value between 0 and 1 The syntax of the result is thus Retrieving Results N CCDF 0 CCDF 1 10 CCDF 2 10 CCDF N 1 10 10 9 4 6 Constellation This measurement represents the complex constellation points as and Q data See for example IEEE Std 802 11 2012 Fig 18 10 BPSK QPSK 16 QAM and 64 QAM constellation bit encoding Each and Q point is returned in floating point format Data is returned as a repeating array of interleaved and Q data in groups of selected carriers per OFDM Symbol until all the and Q data for the analyzed OFDM Symbols is exhausted The following carrier selections are possible e All Carriers CONFigure BURSt CONStellation CARRier SELect ALL Ns pairs of and Q data per OFDM Symbol OFDM Symbol 1 l1 Q 4 Uu aah Uwe Q1 nst OFDM Symbol 2 l2 1 Q2 4 122 Q22 lost Qo ws OFDM Symbol N Ini Qu In Q
396. ure ment channel see INSTrument SELect on page 176 LAY OURA DDI VANDON citet erre ence ater ae de eo Deere pex bra n 248 LAYout GATalog WINDOW P 1 utetur e cione en aaa 250 Be here 251 LAY outiREMove WINDOW cccccce sagedeceecstecneeconasesssassbgbeaeeeerapeneeeeesdaeeceeesdteeaeceatapauesehs 251 LAYOQUEREPLaco WINDOW E 251 LAVYQUESPI eiii A iia 252 EAY cut WINDOWS ADD coa 253 LAY out WINDoOWSREIDENUfJT 22 dante cott rta beoe tette Liebe at reta dave b edet ubera 254 Bee 254 LAY out WINDowesnsREPLESOg acid 254 LAYout ADD WINDow lt WindowName gt lt Direction gt lt WindowT ype gt This command adds a window to the display 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 lt WindowType gt Return values lt NewWindowName gt Example Usage Manual operation Configuring the Result Display LEFT RIGHt ABOVe BELow Direction the new window is added relative to the existing win dow text value Type of result display evaluation method you
397. ution coder Set to 0 The values for the individual demodulation parameters are described in chapter 5 3 8 Demodulation on page 124 The following abbreviations are used in the Signal Field table Table 3 8 Abbreviations for demodulation parameters shown in Signal Field display Abbreviation in Signal Parameter in Demodulation settings Field display Aist Auto same type as first PPDU Al Auto individual for each PPDU M lt x gt Meas only the specified PPDUs lt x gt D lt x gt Demod all with specified parameter lt y gt The Signal Field measurement indicates certain inconsistencies in the signal or dis crepancies between the demodulation settings and the signal to be analyzed In both cases an appropriate warning is displayed and the results for the PPDU are highligh ted orange both in the Signal Field display and the Magnitude Capture display If the signal was analyzed with warnings the results indicated by a message also con tribute to the overall analysis results R amp S FSW K91 Measurements and Result Displays EH PPDUS detected in the signal that do not pass the logical filter i e are not to be inclu ded in analysis are dismissed An appropriate message is provided The correspond ing PPDU in the capture buffer is not highlighted The numeric trace results for this evaluation method are described in chap ter 10 9 4 13 Signal Field on page 288 Remote co
398. val Displayed Length PPDUS ssuss 131 137 221 222 H High pass filter loc I 186 A A 94 Hysteresis Lower Auto level Wlgger cerent Upper Auto level 1 Q data Export file binary data description 316 Export file parameter description 313 Exportitig e cernentes Exporting remote Exporting Importing Importing n Importing remote Importing Exporting TE Maximum bandwidth Sample TA cias UO measurements Configuring remote he VQ mismatch zur err cla UO Mismatch Compensation treten eem VQ OSCE i tr ttti rers Limit check result remote Limits remote ctc cepe tes UO Power Trigger SOftKey 2 aero teo Trigger level remote m eg IEEE 802 11a Signal elen ME 54 IEEE 802 11a g OFDM Literature viii 61 Modulation formats rnt rene 77 IEEE 802 11g OFDM Signal PrOCESSING isis ns 54 IEEE 802 11n Modulation formats rrt tee 77 IF Power Trigger Cen EE 110 Trigger level remote 2 rrt 207 Impedance ceste 187 Iu in HR 93 Importing VQ dala ste crees 1 Q data remote SOfIKGy cocaina P enne ends Input Analog Baseband Interface B71 settings 97 GO P NG EE ee e CHE 186 Coupling default 2 t dci 88 Digital Baseband Interface B17 settings 94 Ov
399. valid PPDU is detected and subsequent PPDUS are analyzed only if they have the same format corre sponds to Auto same type as first PPDU ALL All PPDUs are analyzed regardless of their format corresponds to Auto individually for each PPDU MNHT Only PPDUs with format Non HT are analyzed IEEE 802 11 a g OFDM p DNHT All PPDUs are assumed to have the PPDU format Non HT IEEE 802 11 a g OFDM p MMIX Only PPDUs with format HT MF Mixed are analyzed IEEE 802 11 n MGRF Only PPDUs with format HT GF Greenfield are analyzed IEEE 802 11 n DMIX All PPDUs are assumed to have the PPDU format HT MF IEEE 802 11 n DGRF All PPDUs are assumed to have the PPDU format HT GF IEEE 802 11 n MVHT Only PPDUs with format VHT are analyzed IEEE 802 11 ac DVHT All PPDUs are assumed to have the PPDU format VHT IEEE 802 11 ac FMMM Only PPDUs with specified format are analyzed see SENSe DEMod FORMat BANalyze on page 227 IEEE 802 11 b g DSSS FMMD All PPDUs are assumed to have the specified PPDU format see SENSe DEMod FORMat BANalyze on page 227 IEEE 802 11 b g DSSS RST FBURst SENS DEM FORM BAN BTYP AUTO TYPE FBUR Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Manual operation See PPDU Format to measure on page 125 See PSDU Modulation to use on page 126 See PPDU Format to measure PSDU Modul
400. w 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 lt Direction gt LEFT RIGHt ABOVe BELow lt WindowType gt Type of measurement window you want to add See LAYout ADD WINDow on page 248 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 10 7 3 Configuring the Result Display 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 Note to query the index of a particular window use the LAYout IDENtify WINDow 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 LAY out WINDow lt n gt REMove This command removes the window specified by the suffix lt n gt from the display 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 This command changes the window type of an existing window specified by the suffix lt n gt The result of thi
401. wer trigger This command is available for the Digital Baseband Interface R amp S FSW B17 and the Analog Baseband Interface R amp S FSW B71 Parameters lt Level gt Range 50 dBm to 20 dBm RST 20 dBm Example TRIG LEV BB 30DBM Manual operation See Trigger Level on page 113 TRIGger SEQuence LEVel BBPower lt Level gt This command sets the level of the baseband power trigger Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance This command is available for the Digital Baseband Interface R amp S FSW B17 and the Analog Baseband Interface R amp S FSW B71 Parameters lt Level gt Range 50 dBm to 20 dBm RST 20 dBm Example TRIG LEV BB 30DBM Manual operation See Trigger Level on page 113 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 Note that the variable INPUT OUTPUT connectors ports 2 3 must be set for use as input using the OUTPut TRIGger lt port gt DIRection command For details on the trigger source see Trigger Source Settings on page 109 Suffix lt port gt Selects the trigger port 1 trigger port 1 TRIGGER INPUT connector on front panel 2 trigger port 2 TRIGGER INPUT OUTPUT connector on front panel 3 trigger port 3 TRIGGER3 INPUT OUTPUT connector on rear panel Parameters lt TriggerLevel gt
402. which is indicated by the IF OVLD status display This value is overwritten if Auto Level mode is turned on Remote command DISPlay WINDow lt n gt TRACe Y SCALe RLEVel on page 199 Signal Level RMS Reference Level Settings Specifies the mean power level of the source signal as supplied to the instrument s RF input This value is overwritten if Auto Level mode is turned on Remote command CONFigure POWer EXPected RF on page 199 Shifting the Display Offset Reference Level Settings Defines an arithmetic level offset This offset is added to the measured level irrespec tive of the selected unit The scaling 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 FSW so the application shows correct power results All displayed power level results will be shifted by this value Note however that the Reference Level value ignores the Reference Level Offset It is important to know the actual power level the R amp S FSW must handle To determine the required offset consider the external attenuation or gain applied to the input signal A positive value indicates that an attenuation took place R amp S FSW increases the displayed power values a negative value indicates an external gain R amp S FSW decreases the displayed power values The setting range is 200 dB in 0 01 dB steps Remote command DISPlay WINDow lt n gt TRA
403. y a connected R amp S FS Z11 trigger unit simultaneously for all connected analyzers For details see chapter 4 9 5 Trigger Synchronization Using an R amp S FS Z11 Trigger Unit on page 83 RST IMMediate Example TRIG SOUR EXT Selects the external trigger input as source of the trigger signal Manual operation See Trigger Source on page 110 See Free Run on page 110 See External Trigger 1 2 3 on page 110 See IF Power on page 110 See UO Power on page 111 See RF Power on page 111 See Time on page 111 See Power Sensor on page 112 See Baseband Power on page 112 See Digital UO on page 112 See FS Z11 Trigger on page 114 TRIGger SEQuence TIME RINTerval lt Interval gt This command defines the repetition interval for the time trigger Parameters lt Interval gt 2 0 ms to 5000 Range 2 ms to 5000s RST 1 0s Example TRIG SOUR TIME Selects the time trigger input for triggering TRIG TIME RINT 50 The sweep starts every 50 s Manual operation See Repetition Interval on page 113 Configuring the Trigger Output The following commands are required to send the trigger signal to one of the variable TRIGGER INPUT OUTPUT connectors The tasks for manual operation are described in Trigger 2 3 on page 99 OUTPULTRIGgerporn gt DIRCCHON id rn n uan cedet ent ede ade aed 212 OUTPut TRIGger port LEVel 2 1 riore oda 212 OUTPUE TRIGgersport eh d 212 OUTPut TRIOaer pont PULSedMMe
404. ymbol errors The example shows that it is actually necessary to estimate and compensate the clock deviation which is accomplished in the next block Referring to the IEEE 802 11a g OFDM measurement standard 6 the timing drift phase x ming is not part of the requirements Therefore the time tracking is not activa ted as the default setting of the R amp S FSW WLAN application see Timing Error Track ing on page 123 The time tracking option should rather be seen as a powerful ana lyzing option In addition the tracking of the gain g in FFT is supported for each symbol in relation to the reference gain g 1 at the time instant of the long symbol LS At this time the coarse channel transfer function HS is calculated This makes sense since the sequence rj is compensated by the coarse channel trans fer function AS before estimating the symbols Consequently a potential change of the gain at the symbol caused for example by the increase of the DUT amplifier temperature may lead to symbol errors especially for a large symbol alphabet M of the MQAM transmission In this case the estimation and the subsequent compensation of the gain are useful Referring to the IEEE 802 11a g OFDM measurement standard 6 the compensa tion of the gain g is not part of the requirements Therefore the gain tracking is not activated as the default setting of the R amp S FSW WLAN application see L evel Error Gain Tracking on
405. ysical cirios Closing Channels remote e rrt eret 174 Windows remote seirc Kinra t ihren 251 254 Compensating IEEE 802 118 9 OFDM 55 iir ft 59 Payload window IEEE 802 11a g OFDM 56 Compensation VO MISMATCH sie e rer recentes 123 Complementary cumulative distribution function ses CCD rm 50 Constellation Result display rrr rer t intr 27 vs carrier result display vs carrier trace dala hebt vs syr bol trace data ccrte Continue single sweep SOKOV eege Goin exce De pat 146 Continuous Sequencer kc 86 Continuous sweep kh c TE Solara 146 Conventions SEPICOMMANOS sumo lira 168 Copying Measurement channel remote 173 Coupling Inp t femote c aee tette ies 186 Crest Factor D Data acquisition Manual MIMO c ococccocccocinccnoccncconnnoncnancnncanccnnono MIMO capture method MIMO Er EE see Signal capturing Data format E rue EH 276 A deeg Seege ER Tee ER Data streams Mapping MIMO sseeen 139 Data symbols Estimating IEEE 802 11a g OFDM 59 ld rue EE 2 Number of displayed ser acatar oso DC offset Analog Baseband B71 remote control 193 194 Default values FSC EE 88 Demodulation BASICS ee A ees 77 Configuring 124 Configuring remote 220 Beien GE 77 Parameters tc geseet

R&S FSW WLAN Application User Manual

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R&amp;S FSW WLAN Application User Manual

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R&S FSW WLAN Application User Manual