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R&S FPS WLAN Application User Manual

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1. 12 Bitstream Result display Tace data roce e ed Ica Lees Block diagram IEEE 802 11a g OFDM lp 57 C Capture buffer SIUE cto 35 Capture buffers Clearing MIMO cocoa ri 118 Used MIMO sin coser eee rir ere eor 118 Capture offset MSRA applications ssssss 106 112 119 Remote Softkey Capture ME o ree ER ate te eren nie eed 12 14 106 erc pep 92 Bisplayed cirios wie 10 see also Measurement time ooconcccccinccccnocccccnanccinanos 202 Carriers foil T M 79 CCDF Configuring applications scssi 154 Results d Trace E EEN 291 CSMENMEQUENCY EE 100 Default s Ertof 007 Softkey E Rip Channel Estimating Estimating IEEE 802 11a g OFDM j p 63 Channel bandwidth MSRA MOUE EE 88 Channel bandwidth CBW Default ecc tapas 92 PPDU s 124 125 127 128 131 133 134 223 Channel bar Displayed informaltioti neo nne 10 Channel estimation A M Remote control Channel power ACUR see AGUR EE 51 Channels ACME TE NEE 79 AWGN IEEE 802 11a g OFDM j p 22 59 Ee EE SEN ACT PHYSICAL EE 73 Closing Channels remote asirica 181 Windows remote A 249 252 Compensating IEEE 802 1 ta 0 OFDM j D 62 Payload window IEEE 802 11a g OFDM j p 59 Compensation l Q MiSmatCli E 122 Complementary cumulative distribution function See C
2. Reference Power Peak Vector Error IEEE Meas Range Fig 5 7 Evaluation range settings for IEEE 802 11b and g DSSS standards PPDU Statistic Count No of PPDUS to Afhalyze tete ttes 141 e UR EE Le Lt EE 142 Min Max Payload Length ais cocos teen rera netter cann Re a preis 142 PYT Ara Deng cente da adeb eet 142 PVT Reference EE 142 Peak Vector Emor Meas Rage E 142 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 10 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 233 SENSe BURSt COUNt on page 232 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Equal PPDU Length If enabled only PPDUs with the specified Min Max Payload Length are considered for measurement analysis If disabled a maximum and minimum Min Max Payload Length can be defined and all PPDUs whose length is within this rang
3. 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 FETCh BURSt AM AM COEFficients command Parameters lt Degree gt integer Range 1 to 20 RST 4 Example CONF BURS AM AM POLY 3 Manual operation See AM AM on page 22 DISPlay WINDow lt n gt TRACe lt t gt X SCALe AUTO State DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO State This command activates or deactivates automatic scaling of the x axis or y axis for the specified trace display If enabled the R amp S FSW WLAN application automatically scales the x axis or y axis to best fit the measurement results If disabled the x axis or y axis is scaled according to the specified minimum maximum values see DISPlay WINDow n TRACe t Y SCALe MINimum DISPlay WINDow lt n gt TRACe lt t gt Y SCALe MAXimum and number of divi sions see DISPlay WINDow lt n gt TRACe lt t gt Y SCA
4. 16 Programming example sese 308 Status bar Error messages centena 172 Status registers A tL fevered baad 302 Querying e STATus QUEStionable SYNC esessss 302 WEAN WEE 302 STBC zr PPDUS remote Suffixes een une EE 174 Remote command Sissit KENNEN eerta ae 176 SWap Q riso 107 REMOTE E E E A A T ES 202 Sweep Tue E Configuration softkey ht Time remote Symbol clock ro error limit remote re Error limit check result remote 278 Symbols Count remote excita RE Long IEEE 802 11a g OFDM j p Short IEEE 802 11a g OFDM j p SynchronizatiORh sssini ariris ed Remote control cuate T Timing A paai a EE 59 Detection IEEE 802 11a g OFDM j p 59 Deviations cca era estne ctia ave 34 FING uus Tracking i eee eerte Tracking IEEE 802 118 g OFDM j p Timing errot trackilig eebe oreet ett rrt Tolerance Parameters E 12 Traces Querying results ege eege erret eid 21 Res llS remote uice err rcr eee fent 283 Tracking 5 eee 33091 crosstalk da Delia di e 92 Level TOS cocidas 122 215 216 Phase drift Ile i e Remote Control iesse nsi eaten 214 TMN EOTS eorura er acne 122 217 Trigger Configuration remote sissien Configuration softkey Defa
5. ce 152 Resulta 51 Results PEMOtE vsi noniin aaas 280 Activating WLAN measurements remote Additive white Gaussian noise AWGN Adjacent channel leakage ratio e EE 51 Adjacent channels Filtering Out irte ete 107 202 AM AM el Kugel EI e EE 145 Result displays RE E EE AM EVM Result display ains 23 Trage data iii ici 290 AM PM IS Sult displays siria raid 23 co breeds oes 290 Amplitude Configuration remote Configuration softkey Se SONGS Analysis Bandwidth definition ccoo 313 Remote control 298 RF measurements se 106 fuper m DD 156 Analysis interval MSRA ius 105 119 201 EI 88 Antennas Assignment MIMO ctr tineis 115 Mapping MIMO nsee 138 MIMO Settings xicos nannte 114 OSP switch box 117 State MIMO inicia 114 Applications Adopted parameters vincia oe 91 Switching AMONIO WEE A O 104 Der acia eds 92 Electronic 2 104 Manual 2 104 elle 104 Auto level Reference level ooooococccococococccocccocooonncnnccccnnnnnno 104 150 jc m 104 150 Auto settings Remote control Auto track time Remote control rrr ec tni 198 B Bandwidth Coverage MSRA mode esses 88 Extension options 2313 Maximum usable 313 M n aa 91 Relationship to sample rate ssss 314 Bit error rate BER il e
6. 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 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 91 Configuring the Result Display O 11 7 1 The suffix lt n gt in the following remote commands represents the window 1 16 in the currently selected measurement channel e General Window COMMANdS ccomicccninnmcinnsccia cnc 245 e Working with Windows in the Display 246 e Selecting Items to Display in Result Summairy eee 252 e Configuring the Spectrum Flatness and Group Delay Result Displays 253 e Configuring the AM AM Result Display 254 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 183 DISPla FORMAL e DRE 245 DISPlay A MINDOW ER E 245 DISPlay FORMat lt Format gt This command determin
7. lt n gt is irrelevant Parameters lt Position gt Position of the analysis line in seconds The position must lie within the measurement time of the MSRA measurement Default unit s CALCulate lt n gt MSRA WINDow lt n gt IVAL This command queries the analysis interval for the window specified by the WINDow suffix lt n gt the CALC suffix is irrelevant This command is only available in application measurement channels not the MSRA View or MSRA Master Return values lt IntStart gt Start value of the analysis interval in seconds Default unit s lt IntStop gt Stop value of the analysis interval in seconds Usage Query only 11 6 Configuring Frequency Sweep Measurements on WLAN Signals INITiate lt n gt REFResh This function is only available if the Sequencer is deactivated SYSTem SEQuencer SYST SEQ OFF and only for applications in MSRA mode not the MSRA Master The data in the capture buffer is re evaluated by the currently active application only The results for any other applications remain unchanged The suffix lt n gt is irrelevant Example SYST SEQ OFF Deactivates the scheduler INIT CONT OFF Switches to single sweep mode INIT WAI Starts a new data measurement and waits for the end of the Sweep INST SEL IQ ANALYZER Selects the IQ Analyzer channel INIT REFR Refreshes the display for the UO Analyzer channel Usage Event Manual operation See Refresh on
8. CF 100 0 MHz Mean Pwr 20 00 dB 2 Result Summary Samples 500000 lo 1 0 1 Crest 0 01 66 dB lean Peak Trace 1 7 22 dBm 3 34 dBm 10 56 dB Fig 3 30 CCDF measurement results Remote command CONFigure BURSt STATistics CCDF IMMediate on page 191 Querying results CALCulate lt n gt MARKer lt m gt Y on page 299 CALCulate lt n gt STATistics RESult lt t gt on page 282 Evaluation Methods for Frequency Sweep Measurements The evaluation methods for frequency sweep measurements in the R amp S FPS WLAN application are identical to those in the R amp S FPS base unit Spectrum application DAG ENS inian aE E E A EN Eaa 55 Posut SOT EE 55 Marker Ke 55 Markor Peak USt PTT erena aaa ita 56 IESSE User Manual 1176 8551 02 06 54 R amp S FPS K91 Measurements and Result Displays 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 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 246 Result Summary Result summaries provide 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 descript
9. 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 SENSe 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 131 11 5 8 Evaluation Range The evaluation range defines which data is evaluated in the result display Configuring the WLAN IQ Measurement Modulation Accur
10. Parameters lt Offset gt RST Os Example TRIG HOLD 500us Manual operation See Trigger Offset on page 111 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 111 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Manual operation See Hysteresis on page 111 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
11. 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 FPS For the definition of this element refer to the RsIqTar xsd schema Note that the preview can be only displayed by current web browsers that have JavaScript enabled and if the XSLT stylesheet open 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 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 Q Data File Format iq tar lt Min gt lt ArrayOfFloat length 256 gt lt float gt 134 lt float gt lt float gt 142 lt float gt lt float gt 140 lt float gt lt ArrayOfFloat gt lt Min gt lt Max gt lt ArrayOfFloat length 256 gt lt float gt 70 lt float gt lt float gt 71 lt float gt float 69 float ArrayOfFloat lt 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 l
12. Remote command CONF WLAN MIMO CAPT TYP MAN see CONFigure WLAN MIMO CAPTure TYPE on page 212 Single Cont Manual Sequential MIMO Data Capture 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 211 INITiate lt n gt IMMediate on page 261 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 261 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 User Manual 1176 8551 02 06 118 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Reference Frequency Coupling For simultaneous MIMO setups you can set the reference frequency source for all slave devices to the same setting as the master device Slaves Refer Both the master and all slaves use the same reference according to ence same as the setting at the master Master setting Slaves Exter The slave devices are set to use the external reference from the mas nal Master ter The master device uses its internal reference Internal Configure the
13. The HT SIG length and the length estimated by the R amp S FPS application from the PPDU power profile are different User Manual 1176 8551 02 06 172 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 The spatial mapping can not be applied due to a rectangular mapping matrix the number of space time streams is not equal to the number of transmit antennas 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
14. This command works only if you have selected a user defined output with OUTPut TRIGgereport OTYPe Suffix port Selects the trigger port to which the output is sent 2 TRG AUX Parameters lt Level gt HIGH TTL signal LOW OV RST LOW Manual operation See Trigger 2 on page 99 See Level on page 99 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 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 TRG AUX Parameters lt OutputType gt DEVice Sends a trigger signal when the R amp S FPS has triggered inter nally TARMed Sends a trigger signal when the trigger is armed and ready for an external trigger event UDEFined Sends a user defined trigger signal For more information see OUTPut TRIGger lt port gt LEVel RST DEVice Manual operation See Ouiput Type on page 99 OUTPut TRIGger lt port gt PULSe IMMediate This command generates a pulse at the trigger output Suffix lt port gt Selects the trigger port to which the output is sent 2 TRG AUX Usage Event Manual operation See Send Trigger on page 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 th
15. 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 decimal point depends on the type of numeric value Example Setting SENSe FREQuency CENTer 1GHZ Query SENSe FREQuency CENTer would return 1E9 In some cases numeric values may be returned as text e INF NINF Infinity or negative infinity Represents the numeric values 9 9E37 or 9 9E37 e NAN 11 2 6 2 11 2 6 3 11 2 6 4 11 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
16. 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 Cz Carrier 25 Carr Carrie D 2 ai Carrier 25 Carr 3 5 Stream 2 Rx 1 3 6 Stream 2 Rx 2 3 7 Stream 2 Rx 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 C 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 Thus 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 11 9 4 14 Group Delay on page 295 Remote command LAY ADD
17. 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 Q 0 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 O 1 Q 0 1 Channel 0 Complex sample 1 1 1 Qf1 1 Channel 1 Complex sample 1 2 315 0121111 Channel 2 Complex sample 1 0 21 Q 0 2 Channel 0 Complex sample 2 1 Fed Ol Peay Channel 1 Complex sample 2 21 2 0121121 Channel 2 Complex sample 2 Example Element order for complex cartesian data 1 channel This example demonstrates how to store complex cartesian data in float32 format using MATLAB Save vector of complex cartesian I Q data i e iqiqiq N 100 iq randn 1 N 1j randn 1 N fid fopen xyz complex float32 w for k 1 length iq fwrite fid single real iq k f10at32 UO Data File Format iq tar fwrite fid single imag iq k float32 end fclose fid List of Remote Commands WLAN SENSE ADIJUSEWEV Sari e Sarena lage 240 SENSe BANDwidth CHANneLEAUTO TYPE isisa e cid 223 SENSe BANDwidth RESolution FIL Ter S TATe esses eene eren ener 202 SENSe BURSECOUN 2c a et nto e D ace D ane eet
18. 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 FPS WLAN application also performs statistical evaluation over several PPDUs and displays one or more of the following results 3 1 1 1 3 1 1 2 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Table 3 3 Calculated summary results Result type Description Min Minimum measured value Mean Limit Mean measured 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 de de de de do 02 de ab oa rs drehen Fig 3 1 1 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
19. Receiving Data Input and Providing Data Output Standard Modulation formats PPDU formats Channel bandwidths IEEE 802 11n SISO HT MF Mixed format 20 MHz 40 MHz BPSK 6 5 7 2 13 5 amp HT GF Greenfield format 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 requires R amp S FPS bandwidth extension option see chapter A 1 Sample Rate and Maximum Usable 1 Q Bandwidth for RF Input on page 313 Receiving Data Input and Providing Data Output The R amp S FPS can analyze signals from different input sources and provide various types of output such as noise or trigger signals Input from Noise Sources The R amp S FPS provides an optional NOISE SOURCE CONTROL connector with a volt age supply for an external noise source By switching the supply voltage for an exter nal 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 FPS itself for example when measuring the noise level of an amplifier In this case you can first connect an external noise source whose noise power level is known in advance to the R amp S FPS and measure the total noise power From
20. 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 12 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 ters on page 12 Return values lt Result gt Global Result Stream 1 result Stream n result 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 as defined by the stand ard For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 12 Return values lt Result gt lt Global Result gt lt Stream 1 result gt lt Stream n result gt Usage Query only FETCh BURSt TFALI AVERage FETCh BURSt TFALI MAXimum FETCh BURSt TFALI MINimum This command returns the average maximum or minimum PPDU fall time in seconds This command is only applicable to IEEE802 11b amp IEEE802 11g DSSS signals For details see chapter 3 1 1 Modulation Accuracy
21. essen 210 GONFigure WEAN ANTMatrix S L ATesstate nce t erret A 211 CONFigure WLAN DUTConfig CONFigure WLAN EXTension AUTO TYPE GONFigure WLEAN GTIMG AU TO cett ertet repetere ene entere e t e tnr ere Eon GONFigure WEAN GTIMS AUTOZTYPE etr rrt tree th nera ce te enne ta c en GONFigure WEAN GTIMB SELBCL scorre et eerte treten lc ena KP RYE SERIA IBS ee de EUN Resp CONFigure ET He e A HTC CONFigur WLAN MIMO CAP Ture BUF Fei iii coincida CONFigure WLAN MIMO CAPTure TYPE CONFigure WEAN MIMO OSP ADDRGSS t iter ttr a te Aa YER dee E EXE Reg RET GONFigure WEAN MIMO OSP MObBDule 52 atto err eth eher brat rrr ae GONFigure WEAN PAYEoad LENG SEG ecco treten rtr ane nera to ore EENEG ENEE ege GONFigure WLAN PVERtor MRANGg6 nente ptt rera ean a 232 EE e e UE RE deel E ee ee EE tele R le CONFigure WLAN SMAPping NORMalise GONFigure WEAN SMAPDping TASCH gt oxida dh Eire eo POWER nns CONFioure WAN SMAboimng T czchzGiReam sttreamz nennen nennen 222 CONFigure WLAN SMAP ping TX ch TIMeshift rnt enne ht nete rot citas 222 CONFigure WLAN STBC AUTO TYPE DIAGnostic SERVICE NS OUNCE P pzig yaselr TRUE SEVEN E RE ee EE On E EE DISPlayEWINDow lt n gt TABLe ITE EE DISPlay WINDow lt n gt TRACe lt t gt X SCALeJ AUTO cononocnconononnorsnoraccnnaranoneconca
22. 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 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 Ref Level 0 00 dBm s RBW 30kHz Att 10 dB SWT 1ms VBW 300kHz2 Mode Auto FFT M1 1 27 37 dBm 2 0996300 GHz 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 2 Hz e m cc Bw 4 166073926 MHz User Manual 1176 8551 02 06 53 R amp S FPS K91 Measurements and Result Displays 3 2 2 For details see chapter 5 4 3 Occupied Bandwidth on page 154 Remote command CONFigure BURSt SPECtrum OBWidth IMMediate on page 190 Querying results CALC MARK FUNC POW RES OBW see CALCulate n MARKer m FUNCtion POWer lt sb gt RESult on page 280 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 154 Ref Level 0 50 dBm 2 AnBW 40 MHz Att d8 Meas Time 12 5 ms
23. Bursts Min Mean 0 0s 4 5 0 ms Carrier 250 50 b armer Carrier 250 2 Constellation 1 Clow 4 EVM vs Symbol s Min Avg Max SEVM 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 MSRA operating mode In MSRA operating mode additional tabs and elements are available A colored back ground of the screen behind the measurement channel tabs indicates that you are in MSRA operating mode For details on the MSRA operating mode see the R amp S FPS MSRA User Manual Channel bar information In the WLAN application the R amp S FPS 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 GI WLAN 802 11a ac n j p 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 setting
24. 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 3 1 1 3 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 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 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 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Fig 3 4 Positive quadrature offset A negative quadrature offset means a phase angle less than 90 degrees Fig 3 5 Negative quadrature offset 3 1 1 4 I Q Skew If transmission of the data on the I 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
25. Ino Qu 2 IN Nused Qu Nused Error vs Carrier Three trace types are provided for gain imbalance quadrature error evaluation TRACE1 The minimum gain imbalance quadrature error value over the analyzed PPDUS for each of the N sey subcarriers TRACE2 The average gain imbalance quadrature error value over the analyzed PPDUs for each of the Ny seq subcarriers TRACE3 The maximum gain imbalance quadrature error value over the analyzed PPDUs for each of the N sey subcarriers Each gain imbalance quadrature error value is returned as a floating point number expressed in units of dB Supported data formats see FORMat DATA on page 283 ASCii UINT Error vs Preamble Three traces types are available for frequency or phase error 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 283 ASCii REAL EVM vs Carrier Three trace types are provided for this evaluation Retrieving Results Table 11 14 Query parameter and results for EVM vs Carrier TRACE1 The minimum EVM value over the analyzed PPDUs for each of the Nusea subcarriers TRACE2 The average EVM value over the analyzed PPDUs for each of the Nusea subcarriers TRACE3 The maximum EVM value over the analyzed PPDUs for each of the N 44 subcarriers Each EVM val
26. Return values Result Global Result Stream 1 result Stream n result 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 12 Return values Result Global Result Stream 1 result Stream n result Usage Query only FETCh BURSt EVM DIRect AVERage FETCh BURSt EVM DIRect MAXimum FETCh BURSt EVM DIRect MINimum This command returns the average maximum or minimum EVM in dB for the IEEE 802 11b standard This result is the value after filtering For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 12 Usage Query only FETCh BURSt EVM PILot AVERage FETCh BURSt EVM PILot MAXimum FETCh 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 12 Return values lt Result gt lt Global Result gt lt Stream 1 result gt lt Stream n result gt Retrieving Results Usage Query only FETCh BURSt EVM IEEE AVERage FETCh BURSt EVM IEEE MAXimum FETCh BURSt EVM IEEE MINimum This command returns the average maximum or minimum EVM in dB
27. TYPOS eet 12 Messages Signal Field 4 retener 172 MIMO EE 70 Antenna assignment errore nene 115 Calculating e 2 ise ee etes 118 Capture buffers ius ice oda 118 Capture Method 3 uiii P a 114 Capture Settings EE 113 Crosstalk miii retenti Ir aee 215 Demodulation settings eee 136 DUT configuration ertet en 114 Joined RX Sync and Tracking ooooococonoccccocccocccicncnnno 115 Manual data capture ttn 118 Manual sequential capture sssssssssss 117 Normalizing ee WEE 137 OSP IP address rrr ertet 116 PPDU synchronization ierre 115 Reference frequency coupling 119 Sequential capture using OSP sssusss 115 Simultaneous capture settings sse 114 Slave analyzets comi i teh 115 Spatial mapping mode enn 137 User defined spatial mapping 138 Minimum bl m 148 Modulation A io a a Ees 80 Inverted UO remote seen 202 liverted IQ uir entree 107 PPDU e 125 126 132 226 PPDU remote nete la 306 PPDUS 25 n ence one oben tient 128 134 Modulation Accuracy Parameters geed dne eeu bp ticus 12 Modulation and Coding Scheme See MOS osea a ie wed re dE EH 128 134 MSR ACLR Results remote tie apes 280 MSRA Analysis interval 1 ue 105 119 201 Operating mo
28. 1 0 Each division on the x axis or y axis displays multiples of 1 10 For example for n 1 division range 0 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 1 0 2 0 Each division on the x axis or y axis displays multiples of 2 10 For example for n 1 division range 0 1 0 0 2 0 4 0 6 0 8 1 0 2 5 Each division on the x axis or y axis displays multiples of 2 5 10 For example for n 1 division range 0 1 0 0 25 0 5 0 75 1 0 5 0 Each division on the x axis or y axis displays multiples of 5 10 For example for n 1 division range 0 1 0 0 5 1 0 Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe PDIVision on page 259 5 3 12 Automatic Settings Some settings can be adjusted by the R amp S FPS 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 13 MSRA operating mode In MSRA operating mode the following automatic settings are not available as they require a new data acquisition However the R amp S FSW WLAN application cannot per form data acquisition in MSRA operating mode Setting the Reference Level Automatically Auto Level 150 Setting the Reference Level A
29. 1 itane na ert san ERa o exu ne iris 274 FETCh BURSETRISS AVERAUGET iiec Ee AANER EEN RD SY apelar Re Eres 275 FETCHBURSETRISS MAXIMU escurrir tex erede na Ad 275 FETCHBURSETRISS MINIMUM EE 275 UNIT EVM ee 275 IC Ee 275 UNIT PS BOW le eo nr m EP or RE t eoi ori ee 275 Retrieving Results 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 12 The results are output as a list of result strings separated by commas in ASCII format The results are output in the following order Global Result Stream 1 result Stream n result Return values Global Result preamble power payload power gt peak power min rms power avg rms power max rms power nan nan nan min freq error gt lt avg freq error max freq error min symbol error avg symbol error max symbol error nan nan nan nan nan nan nan nan nan min EVM all gt avg EVM all max EVM all gt lt min EVM data gt lt avg EVM data gt lt max EVM data gt lt min EVM pilots gt lt avg EVM pilots gt lt max EVM pilots gt nan nan nan nan nan nan nan nan nan nan nan nan lt Stream Results gt nan nan nan nan nan nan p
30. 1299 ounce 101 Frequency offset BICI mc Error limit check result remote zs n uk c Frequency sweep measurements COMMUTING s siete rose orci eire n exe rp ben lee 151 Selec DE 151 WEAN ER 51 Frontend Configuration remote Parameters conii tr eese tei doom ere G Gain Tracking IEEE 802 11a g OFDM j p 61 Gain imbalance B S Group delay Result display sacra 34 Trace data 295 Guardinterval koss tonnin aE 12 Displayed ET 10 Length PPDUS 130 136 218 219 220 H Hysteresis MOI M 111 l 1 Q data Export file binary data description 320 Export file parameter description 317 Exportirig enn Exporting remote Exporting Importing Importing Em Importing remote ee cedes Importing Exporting ET Maximum bandwidth Sample rate reet ea recte tee UO measurements Configuring remote sseessseeesees 191 ege EE 18 UO Mismatch Compensation i eerie rre rent ern e coti rrt 122 VQ OTSE t mui tiia 12 16 Limit check result remote sss 277 Limits remote triente petenda 239 UO Power BEL O 110 Trigger level remote sess 205 VO SKEW sickness er ok hr tacit al aren 18 IEEE 802 11a Signal processi
31. EVM vs carrier result display for IEEE 802 11n MIMO measurements The numeric trace results for this evaluation method are described in on page 293 Remote command LAY ADD 1 RIGH EVC see on page 246 or on page 186 Querying results see on page 293 User Manual 1176 8551 02 06 29 R amp S FPS K91 Measurements and Result Displays EH 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 FPS WLAN application provides two different methods to calculate the EVM two traces are displayed 8 EVM vs Chip 1 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 69 e EVM shows the error vector magnitude calculated with an alternative method that provides higher accuracy of the estimations see also Error vector magnitude EVM R amp S FPS method on page 68 Remote command LAY ADD 1 RIGH EVCH see LAYout ADD WINDow on page 246 or CONFigure BURSt EVM ECHip IMMediate on page 186 CONFigure BURSt EVM ESYMbol IMMediate on page 186 Querying results TRACe lt n gt DATA see chapter 11 9 4 11 EVM vs Chip on page 294 EVM vs Symbol This re
32. IEEE 802 11g 6 IEEE 802 11n 7 IEEE 802 11n MIMO 8 IEEE 802 11ac 9 IEEE 802 11p RST 0 See Standard on page 95 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 Limit Manual operation 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 See Tolerance Limit on page 95 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 11 5 2 Configuring the Data Input and Output LEM TOE svete E A a Aplicada 193 A O O 195 11 5 2 1 RF Input dz uses EE 193 Ilia pu mee 193 INPURFIL Te VIG STATE P T 193 NPUEIMPCU ANG Gi iir ater Renta A DN eaae ende atate beoe ci teas dire a rixae aas 194 lj cimo 194 INPut COUPling lt CouplingType gt This command selects the coupling type of the RF input Parameters lt Co
33. RESult lt Measurement gt This command queries the results of power measurements lt n gt lt m gt are irrelevant This command is only available for measurements on RF data see chapter 3 2 Fre quency Sweep Measurements on page 51 To get a valid result you have to perform a complete measurement with synchroniza tion to the end of the measurement before reading out the result This is only possible for single measurement mode See also INITiate lt n gt CONTinuous on page 261 Suffix lt sb gt 1 2 3 4 5 irrelevant Retrieving 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 upper1 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 Car
34. RIGH FEVP see LAYout ADD WINDow on page 246 or CONFigure BURSt PREamble IMMediate on page 187 CONFigure BURSt PREamble SELect on page 187 Querying results TRACe lt n gt DATA see chapter 11 9 4 9 Error vs Preamble on page 293 Gain Imbalance vs Carrier Displays the minimum average and maximum gain imbalance versus carrier in individ ual traces For details on gain imbalance see chapter 3 1 1 2 Gain Imbalance on page 16 User Manual 1176 8551 02 06 33 R amp S9FPS K91 Measurements and Result Displays 2 Gain Imbalance vs Carrier 1 Mine 2 Avg 3Max Carrier 28 6 Carrier Carrier 28 Remote command LAY ADD 1 RIGH GAIN see ow on page 246 or jure on page 186 Querying results see chapter 11 9 4 8 Error vs Carrier on page 293 Group Delay Displays all Group Delay GD values recorded on a per subcarrier 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 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 Carrier 250 50 1 Carrier Carrier 250 User Manual 1176 8551 02 06 34 R amp S FPS K91 Measurements and Result Displays 3 Group Delay Streami4RXT 4 Stream 1 Rx 1 4 Stream 2 Rx 1 4 Stream 3 Rx 1 4 Stream 4 Rx1 4 St gt
35. ROI 148 SCIECE IM GAS PE 89 SEM Configuring cdma2000 sse 153 Programming example 32911 Result mee EE 52 S quencer iens 89 Abortirig remote initi npo 262 Activating remote eeeeeeee 262 MOG ths asciende doc Eee edo ccce rie 90 Mode remote 4202 Ee 261 e 90 Statea es da 90 Sequential MIMO capture method eee enne 115 Sequential manual MIMO capture method eene 117 Settings OVNIS Wi sata 93 Short symbol SS IEEE 802 11a g OFDM lp 59 Signal capturing DUFStION ui eve e te Remote control ec H Signal description CONTIQUIIND EQ 95 Remote control gt Softkey Sigrial field re tot Ep reet eo nrbe tenen 228 Signal Field PPDU analysis ge edel 124 127 133 Result display imc er nettes 46 Trace data s Signal ll Signal processing IEEE 802 114 9 OFDM EL D ete ete 57 IEEE 802 11b 9 DSSS ote ertet 64 Signal source Ee cir ed taie E erts 194 Simultaneous MIMO capture method remet 114 Single Sequencer eciam 90 Single sweep Slave analyzers IP address MIMO ore tees 115 State MIMO uo ccoo pra 115 Slope Trigger SmartGrid softkey Average Length K91 91n esssss 142 Ref Pow Max Mean k n 142 Softkeys Amplitud
36. Remote command SENSe TRACking TIME on page 217 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 216 UO Mismatch Compensation Activates or deactivates the compensation for I Q mismatch If activated the measurement results are compensated for gain imbalance and quadra ture offset Since the quadrature offset is compensated carrier wise UO skew impair ments are compensated 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 18 Note For EVM measurements according to the IEEE 802 11 2012 IEEE 802 11ac 2013 WLAN standard UO mismatch compensation must be deactivated Remote command SENSe TRACking IQMComp on page 215 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 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
37. SEQuencer on page 264 Suffix lt n gt irrelevant Usage Event Manual operation See Sequencer State on page 90 INITiate lt n gt SEQuencer IMMediate This command starts a new sequence of measurements by the Sequencer Its effect is similar to the INITiate lt n gt IMMediate command used for a single measurement Before this command can be executed the Sequencer must be activated see SYSTem SEQuencer on page 264 Suffix n irrelevant Example SYST SEQ ON Activates the Sequencer INIT SEQ MODE SING Sets single sequence mode so each active measurement will be performed once INIT SEQ IMM Starts the sequential measurements Usage Event Manual operation See Sequencer State on page 90 INITiate lt n gt SEQuencer MODE Mode This command selects the way the R amp S FPS application performs measurements sequentially Before this command can be executed the Sequencer must be activated see SYSTem SEQuencer on page 204 Starting a Measurement A detailed programming example is provided in the Operating Modes chapter in the R amp S FPS User Manual Note In order to synchronize to the end of a sequential measurement using OPC OPC or WAI you must use SING1e Sequence mode For details on synchronization see the Remote Basics chapter in the R amp S FPS User Manual Suffix n irrelevant Parameters Mode SINGIe Each measurement is performed once regardless of the chan
38. Streams Streams Antennas Antennas Streams Streams Y v j f gt Steam gt ama 9 Spatial rei Spatial ti 3 Constellation Parser and d ops bs s Encoder with ga y Synchroni Decoder with agah Demapper Constellation Matrix Q zation and Matrix Q Demod gt 3 Encoder Guard y X v FFT Decoder ESSE Coded Modulation p Grec gt y Qs interval illa s y Q E Combiner Coded Bits Physical Channel Heny Bits Effective Channel Hew Hen Q R Hey y Here QS Herr S Fig 4 3 Data flow from the transmit antenna to the receive antenna User Manual 1176 8551 02 06 71 R amp S FPS 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 71 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 column 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
39. 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 e Q 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 UO 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 RslIqTar xsd In particular the order of the XML elements must be respected i e iq tar uses an ordered XML schema For your own implementation of the 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 lt xml version 1 0 encoding UTF 8 gt 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 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
40. 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 be performed once INIT SEQ IMM Starts the sequential measurements Manual operation See Sequencer Mode on page 90 INITiate lt n gt SEQuencer REFResh ALL This function is only available if the Sequencer is deactivated SYSTem SEQuencer SYST SEQ OFF and only in MSRA mode The data in the capture buffer is re evaluated by all active MSRA applications The suffix lt n gt is irrelevant Retrieving Results Example SYST SEQ OFF Deactivates the scheduler INIT CONT OFF Switches to single sweep mode INIT WAI Starts a new data measurement and waits for the end of the sweep INIT SEQ REFR Refreshes the display for all channels Usage Event 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
41. on page 38 See PvT Full PPDU on page 39 See PvT Rising Edge on page 40 See PvT Falling Edge on page 41 See Quad Error vs Carrier on page 42 See Signal Field on page 46 See Spectrum Flatness on page 49 See Spectrum Emission Mask on page 52 Retrieving Results Table 11 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 246 The results for the various window types are descri bed in chapter 11 9 4 Measurement Results for TRACe lt n gt DATA TRACE lt n gt on page 287 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 286 Table 11 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 ran
42. used as estimates and a7 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 rx 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 u 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 j p 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 compensated and the data symbols are known The long observation interval of nof symbols symbols compared to the short i
43. 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 Sample Rate and Maximum Usable UO Bandwidth for RF Input A Annex Reference A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input Definitions Input sample rate ISR the sample rate of the useful data provided by the device connected to the input of the R amp S FPS User Output Sample rate SR the sample rate that is defined by the user e g in the Data Aquisition dialog box in the UO Analyzer application and which is used as the basis for analysis or output e Usable UO 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 FPS 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 l Q data acquisition digital decimation filters are used internally in the R amp S FPS The passband of these digital filters determines the maximum usable WC bandwidth In consequence signals within the usable UO bandwidth passband remain unchanged while signa
44. 1 RIGH GDEL see LAYout ADD WINDow on page 246 or CONF BURS SPEC FLAT SEL GRD see CONFigure BURSt SPECtrum FLATness SELect on page 188 and CONFigure BURSt SPECtrum FLATness IMMediate on page 189 Querying results TRACe lt n gt DATA see chapter 11 9 4 14 Group Delay on page 295 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 A blue bar indicates the selected PPDU if the evaluation range is limited to a single PPDU see Analyze this PPDU PPDU to Analyze on page 139 User Manual 1176 8551 02 06 35 R amp S FPS K91 Measurements and Result Displays 1 Magnitude Capture MUA Rx1 Rx2 1 1 Rx 1 Freq 13 25 GHz Att 4 dB 2 0000125 ms Fig 3 16 Magnitude capture display for single PPDU evaluation 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 70 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 subwind OWS 1 Magnitude Capture RRIA Rx 1 Rx2 Rx3 Rx4 I T RX 1 Freq 5 775 GHz Att 24 dB PASO 1 2 Rx 2 Freq 5 775
45. 11b g DSSS standards Parameters Value Manual operation See PVT Average Length on page 142 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 on page 142 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 on page 140 CONFigure WLAN PVERror MRANge Range 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 DSSS only Return values Range 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 S
46. 120 EET Start Offset cerne ree A b a oe cereos 120 Power Interval Search If enabled the R amp S FPS 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 214 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 command SENSe DEMod FFT OFFSet on page 213 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 61 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Tracking Channel E
47. 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 192 5 3 4 Input and Frontend Settings The R amp S FPS 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 UO data from the WLAN application can be expor ted for further analysis in external applications See chapter 7 1 Import Export Functions on page 157 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 FPS for the Expected Input Signal Frontend Parameters on page 82 e Input So
48. 303 STATusOUEGtonable ACL jmmitCONDitton ennemis 304 STATus QUEStionable ACPLimitENABle rero rrt rhet repete ce EE 304 STATus QUEStionable ACPl imit N TERGnSIHO ioco iiie des rotten ci Gene neces 305 STATusOUEG onable AC mit P Ransiton A 305 STATus QUEStionable ACPLIM EVEN geerdegreeegueerdekieeee gege 304 STATus QUEStionable CONDition STATuS QUEStUonable ENABIG eoo reegen STATus QUEStionable LIMit h CONDITION our ete ettet rettet tp eta te de eats 304 S TATUs QUEStionable EIMiten ENABIG 2 rrr eroe rer cti denise 304 SGTATusOUEG onableL Mit znzNTRansttion eene enne nn cnn rra nana nnn EEEE 305 STATus QUEStionable LIMit n P TRANSOM 22 0 correr Eed EENEG cie never etr pede nae 305 STAT s QUEStionable EIMit amp rnis EVENt J iiri ori rrt ki rare en Rr tirer rir een 304 STATus QUEStionable NTRansition STATus QUEStonable PTRatsitlOD succc erect a dept etr gen Ernte eges STAT s QUEStionable S deer ei Tee REN 304 STATus QUEStionable SYNC ENABIE 0 ccccccceeecceeceeeeeeeeeeeeeeeaeeeaeesceeeeaeescseecaeecaeeseaeseseeseaeeeeeeneeeseeenaes 304 STATus QUEStiOnable SYNG NT RANSOM i cocti orte A 305 STAT S QUESti nable SYNC P TRANSO cotone A is EXE ERE edad 305 STATusOUEGtonable GvNCTEVMENUN nennen nnne enne nennen reser nnne 304 STATus QUESItionable EVENIJ s ict sere rete gene ert e epe ee ee e v t eee pev dp detuvo 304 STAT s QUEUeSENEJXT 2 t inier reote htt rene egr
49. 400 000 000 00 ferz z pep 20 00 dem rel 20 00 fev B Fes 2 400 000 000 00 crz z ec 20 00 m Toe n va OUT A ALC Auto B ALC Auto Transmission Bandwidth Configure Baseband B from Baseband A Transmit Antennas Setup Frame Block Configuration 802 11n A 7 Select the Transmission Bandwidth 40MHz In the IEEE 802 11n WLAN AT dialog press the Frame Block Configuration button to open the IEEE 802 11n WLAN A Frame Blocks Configuration dialog Measurement Example Setting up a MIMO measurement 2 400 000 000 00 crz z 20 00 im 2 400 000 000 00 cr 20 00 t A ALC Auto B ALC Auto cl EN 8 Select Antennas 2 In the IEEE 802 11n WLAN A dialog press the Frame Block Configuration button to open the IEEE 802 11n WLAN A Frame Blocks Configuration dialog Measurement Example Setting up a MIMO measurement Perl 2871 dim ted 20 00 tam 2 400 000 000 00 sH2 reu Per H D dm tex 20 00 im Info A ce 2 400 000 000 00 css rou A ALC Auto B ALC Auto E IEEE 802 11n WLAN A Frame Blocks Configuration Append msert mee Copy Pese 9 Select Tx Mode HT 40MHz Press the PPDU Config button to open the IEEE 802 11n WLAN A PPDU Configuration for Frame Block 1 dialog Measurement Example Setting up a MIMO measurement 2 400 000 000 00 ce o l Pep 8 dem Lev 20 00 em 2
50. 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 124 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 Ness see Extension Spatial Streams sounding on page 135 CRC Cyclic redundancy code WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Table 3 7 Demodulation parameters and results for Signal Field result display IEEE 802 11n Parameter Description Format PPDU format used for measurement Not part of the IEEE 802 11n signal field displayed for convenience see PPDU Format to measure on page 124 MCS Modulation and Coding Scheme MCS index of the PPDU as defined in IEEE S
51. 802 11 configuration Overview For further details about the Occupied Bandwidth measurements refer to Measuring the Occupied Bandwidth in the R amp S FPS User Manual To restore adapted measurement parameters the following parameters are saved on exiting and are restored on re entering this measurement 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 5 Predefined settings for WLAN 802 11 CCDF measurements Setting Default value CCDF Active on trace 1 Analysis bandwidth 10 MHz Frequency Sweep Measurements Setting Default value Number of samples 62500 Detector Sample The CCDF measurement can be configured in the CCDF tab of the Analysis di
52. CALCulate LIMit BURSt EVM ALL AVERage RE Gu 276 CAL Culate L IM BURGGCEVM ALL M Aximum RESuI 276 Retrieving Results CALOCulate LIMit BURStEVM DATA AVERage RESUIt sese 276 CAL Culate L IM BURGGEVMDATAMAXimum REGuI 276 CALOCulate LIMit BURStEEVM PILot AVERage RESUIt essen 277 CALCulate LIMit BURSt EVM PILot MAXimUM RESUIt ccccccccssssceceseeecesecesseseeeaeees 277 CALOCulate LIMit BURStFERRor AVERage RE Gut 277 CALCulate LIMit BURSt FERRor MAXimMUM RESUIt cccccssccceescceceeceeesseeeceeeceeseeeeees 277 CALCulate LIMit BURSt IQOFfset AVERage RESUIt eese 277 CALCulate LIMit BURSt IQOFfset MAXIMUM RE Gul 277 CALCulate LIMit BURSt SYMBolerror AVERage RESUIt sse 278 CALCulate LIMit BURSt SYMBolerror MAXimum RESUIt lees 278 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 237 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 Th
53. CONFigure BURSt PVT SELect on page 187 CONFigure BURSt PVT IMMediate on page 187 Querying results TRACe lt n gt DATA see chapter 11 9 4 17 Power vs Time Full Burst and Rising Falling Data on page 296 Quad Error vs Carrier Displays the minimum average and maximum quadrature offset error versus carrier in individual traces For details on quadrature offset see chapter 3 1 1 3 Quadrature Offset on page 17 User Manual 1176 8551 02 06 42 R amp S FPS K91 Measurements and Result Displays Carrier 28 6 Carrier Carrier 28 Remote command LAY ADD 1 RIGH QUAD see on page 246 or on page 188 Querying results see on page 293 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 Ween TURK I TR 2IRXZ Limit i i Mean Limit 20 00 2C 20 00 Limit Mean Limit E CUR Limit Fig 3 24 Detailed Result Summary result display for IEEE 802 11n MIMO measurements User Manual 1176 8551 02 06 43 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance The Result Summary Detailed contains the following information Note You can configure which results are displayed see chapter 5 3 11 Result Con figuration on page 143 However the results are always calcul
54. 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 E e 2 m af j atm w LI at L Y r v Z xe lav x eI _ 9 x silv Ba x Salv Ago x Salv 0 jOn v 0 Cost function for signal parameters 4 10 where 9 go the variation parameters of the gain used in the I Q branch Aga the crosstalk factor of the Q branch into the I branch S V Sa 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 Ja 9q 9 Gain imbalance Gain imbalance 4 11 The quadrature error is a measure for the crosstalk of the Q branch into the I branch Quadrature Error ARG o jxAgq
55. Flatness and Tolerance Parame ters on page 12 Usage Query only 11 9 1 3 Retrieving Results FETCh BURSt TRISe AVERage FETCh BURSt TRISe MAXimum FETCh BURSt TRISe MINimum This command returns the average maximum or minimum burst rise time in seconds This command is only applicable to IEEE802 11b amp IEEE802 11g DSSS signals For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 12 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 12 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 12 Parameters Unit DB PCT RST DB UNIT PREamble lt Unit gt This command specifies the units for preamble error results Parameters lt Unit gt HZ PCT 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 275 e UNIT GIMBalance on page 275 Remote commands exclusive to retrieving limit check results CAL Gul ted IMIEBURSUAEETESUIt da ioar airde 276
56. I branch see Gain imbal ance UO offset quadrature error on page 68 Center frequency error Hz Frequency error between the signal and the current center frequency of the R amp S FPS the corresponding limits specified in the standard are also indica ted The absolute frequency error includes the frequency error of the R amp S FPS and that of the DUT If possible the transmitterR amp S FPS and the DUT should be synchronized using an external reference See R amp S FPS 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 FPS 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 FPS and the DUT should be synchronized using an external reference See R amp S FPS 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
57. INITiate lt n gt 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 Selecting a Measurement Usage Event Manual operation See Group Delay on page 34 See Specirum Flatness on page 49 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 188 Results are only displayed after a measurement is executed e g using the INI Tiate lt n gt 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 34 See Spectrum Flatness on page 49 CONFigure BURSt STATistics BSTReam IMMediate 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 t
58. Max Payload Length are considered for measurement analysis If disabled a maximum and minimum Min Max Payload Length can be defined and all PPDUs whose length is within this range are considered Remote command IEEE 802 112 g OFDM SENSe DEMod FORMat BANalyze SYMBols EQUal on page 236 IEEE 802 11 b g DSSS SENSe DEMod FORMat BANalyze DURation EQUal on page 234 SENSe DEMod FORMat BANalyze DBYTes EQUal on page 233 Min Max No of Data Symbols 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 236 SENSe DEMod FORMat BANalyze SYMBols MAX on page 236 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 10 2 Evaluation Range Settings for IEEE 802 11b g DSSS The following settings are available to configure the evaluation range for standards IEEE 802 11b g DSSS Y Statistics PPDU Statistic Count No of PPDU s to Analyze Time Domain Source of Payload Length Equal PPDU Length Min Payload Length 1 ys bytes Max Payload Length 66000 us bytes PVT Average Length m
59. 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 Bags Display Config PPDU Stat Count Magnitude Capture ieee soo 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 151 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 89 2 Signal Description See chapter 5 3 3 Signal Description on page 95 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 3 Input Frontend See and chapter 5 3 4 Input and Frontend Settings on page 96 4 Signal Capture See c
60. 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 A frest the not yet compensated frequency deviation e dY the phase jitter at the symbol In general the coarse frequency estimate Af coarse see figure 4 1 is not error free Therefore the remaining frequency error Afrest 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 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 response 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 dri
61. Noise Source on page 98 Frontend Configuration The following commands configure frequency amplitude and y axis scaling settings which represent the frontend of the measurement setup LEE che EET 195 e Amplitude Geittngs A 197 Frequency SENSeJFREQuency CENTER iii ic bte toi roger EE Eget co a praed ei ee EES uua 195 SENS amp I E Eugene ER ep FER ite ta At 196 SENSe FREQuency CENTer STEP AUTO ecce conca no nonononrnn nana 196 SENSE FREQUENCY O PESO aio in cx eR TRR C RE Re eg 197 SENSe FREQuency CENTer lt Frequency gt 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 95 See Center frequency on page 100 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 FRE
62. 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 FPS 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 Eres EVM v 0 N 1 7 S o 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 ve 0 d Ste 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 offset in the I branch and the IQ offset of the Q branch are estimated sepa rately REAL UO offset I branch 4 16
63. S FPS 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 User Manual 1176 8551 02 06 70 R amp S FPS 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 A 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 with 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 72 Using space di
64. 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 Programming Examples R amp S FPS K91 f 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 ee 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 TRAC LEV OFF SENS TRAC PHAS OFF SENS TRAC TIME OFF pe 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 MI 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 2 Evaluation range settings Calculate statistics over 10 PPDUs SENS BURS COUN STAT ON SENS BURS COUN 10 Determine payload length from HT sign
65. TRIGger SEQuence LEVel POWer AUTO lt State gt 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 This function is only considered for TRIG SEQ SOUR IFP and TRIG SEQ SOUR RFP See TRIGger SEQuence SOURce on page 207 In order to define the trigger level manually switch this function off and define the level using TRIGger SEQuence LEVel IFPower on page 205 or TRIGger SEQuence LEVel RFPower on page 206 Parameters for setting and query State 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 110 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 Manual operation See Trigger Level on page 110 TRIGger SEQ
66. Usage Query only 11 11 2 2 11 11 2 3 11 11 2 4 Status Registers 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 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 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 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 Q
67. bandwidth On the R amp S FPS 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 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 operation DNS 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 AUT
68. chapter 11 9 4 18 Signal Field on page 297 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 FPS 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 carriers are displayed including the unused carrier s In contrast to the SISO measurements in previous Rohde amp Schwarz signal and spec trum analyzers the trace is no longer normalized to O dB scaled by the mean gain of all carriers R amp S FPS K91 User Manual 1176 8551 02 06 Measurements and Result Displays 2 Spectrum Flatness Line ABS Upper tine ABS Lower Carrier 250 50 1 Carrier Carrier 250 For more information see on page 78 D Stream ARII Stream 1 Rx 1 4 Stream 2 Rx 1 4 Stream 3 Rx 1 4 Stream 4 Rx 1 4 St 2 2 Stream 1 Rx 2 2 3 Stream 1 Rx 3 2 4 Stream L Rx 4 ABS Upper ABS Lower iai M a m M Er Carrier Camer 25 Carr Carrier Carrier Carrier 2 7 Stream 2 Rx 3 2 8 Stream Carrier Wangen aa
69. 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 EVM Error Vector Magnitude of the payload symbols over all pilot carriers the corresponding limits specified in the standard are also indicated the limits can be changed via remote control not manually see chapter 11 5 9 Limits on page 237 in this case the currently defined limits are displayed here Table 3 2 WLAN UO 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 Stati
70. depend on the selected bandclass Thus the performance of the DUT can be tested and 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 153 IESSEN User Manual 1176 8551 02 06 52 R amp S FPS K91 Measurements and Result Displays Ref Level 41 00 dBm Offset 40 00 dB Mode Auto Sweep Limit Check 31 lt P lt 39 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 12 7 8 000 MHz 000 MHz 2 09153 GHz 39 37 dBm 73 11 dB 18 61 dB 8 000 MHz MHz JO MHz 2 09494 GHz 39 75 dBm 73 48 dB 22 98 dB MHz E Hie 2 09642 GHz 50 91 dBm 84 65 dB 21 15 dB MHz 2 09652 GHz 51 84 dBm 85 57 dB 22 65 dB MH 30 k 2 09739 GHz 52 33 dBm 86 07 dB 34 57 dB MHz t 2 10259 GHz 49 37 dBm 83 11 dB 31 61 dB MHz 3 2 10342 GHz 50 68 dBm 84 42 dB 22 27 dB MHz z 2 10373 GHz 51 81 dBm 85 55 dB 22 05 dB MHz JOO MHz 2 10439 GHz 38 64 dBm 72 37 dB 21 87 dB 50 MHz 000 h 2 11026 GHz 39 24 dBm 72 97 dB 18 47 dB 50 MHz Fig 3 29 SEM measurement results Remote command on page 190 Querying results on page 279 TRAC DATA LIST see on page 284 Occupied Bandwidth The Occupied Bandwidth OBW measurement determines the bandwidth in which in default settings
71. details on the MSRA operating mode see the R amp S FPS MSRA User Manual e General Capture Settings sse 202 e Configuring Triggered Measurements esses 203 MIMO Capture Setihig5 1 iom tci erc dece Hd cur A 209 11 5 4 1 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance General Capture Settings ISENGeIDBANDwOdTRE Solution Fi Ter STATel renn nennnnnneererene 202 ll 202 SENSe SWEep TlME cocine 202 TRACIO SRAT E 203 SENSe BANDwidth RESolution FILTer STATe State This remote control command enables or disables use of the adjacent channel filter If activated 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 j n p on page 107 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 FPS can
72. eee ae 232 SENSe BU RSECOUNESTATO 5c irte odisea tse e it 233 SENSe BURSt SELect SENS6e BURSESEEGGt un eti tht ge lta o Ha ety anol cat de dee SENSe BURSESEE6eGES UAT6 5 tete ties a E 233 SENSe IBURSESEPGOES AT initi pio rere peii cri a 284 SENSe IDEMOG GES HEEN et riter e ec E te ctt a oa ee Ou 215 SENS DEMOd IFFT ORFS a 213 SENSe IDEMOQG FORMGaEBANAlyZ6 d indic tc iiri pe nadine A ce ane 225 SENS DEMod FORMat BANalyz BTY Pe isis iss etri dp e A dp ede e ce e matre cdd d s 306 SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE A 226 SENSe DEMod FORMat BANalyze DBYTes EQUAl essen nenne 233 SENSe DEMod FORMat BANalyze DBYTes MAX essent 234 SENSe DEMod FORMat BANalyze DBYTes MIN 234 SENSe DEMod FORMat BANalyze DURation EQUAal eese enne 234 SENSe DEMod FORMat BANalyze DURation MAX sese eere 235 IEN Ge IDEMod FORMatCBANalvze DURaton MIN 235 SENSe DEMod FORMat BANalyze SYMBols EQUal essen enne 236 SENSe DEMod FORMat BANalyze SYMBols MAX esses eene 236 SENSe DEMod FORMat BANalyze SYMBols MIN eese 236 SENSe DEMod FORMat MCSindex SENSe DEMod FORMatMCSindexMOBE 2 2 certare et eto epa epp 228 SENSe IDEMOG FORMAaENSTSIndex cesis coactus etae ei t cul b teda sc ERE Re ARR Res abate ts 229 SENSe IDEMOG FORMatNSTSindex MODE 2 Ter dec cercare
73. examples ococcccoicconccconcnacccnoninanccnnnc Remote control e RGSUllS ui aee iet ee ted ar ERE Y Y maximum Y minimum feli 148 YIG preselector Activating Deactivating see 97 Activating Deactivating remote 193 Default n ostia 92 Z Zooming Activating remote ee tenete ta 300 Area Multiple mode remote va 304 Area remote 300 Multiple mode remote 300 301 iere P 300 Single mode remote AAA 300
74. 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 228 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 46 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
75. ie PvE dua 229 SENSe DEMod FORMat BCONltent AUTO e citet ees died nee yen 228 IIS RTI IbRBEOCUI mE E a SENSe JFREQuency GEN WK EE SENSe FREQuency CENTer STEP SENSe EREQuency CENTernSTEPIAUT Os ioca da coe ea eat ae ta Rete sae ane EES 196 SENSe IFREQ GnCy OFF Sel inta t tete ee eee aea cn imd apa b eua Ev ides DAR Ee 197 SENSe MSRA GAP Tute OFF Seti torte AU e c tette du ze Pd re E Pte aee ed 242 SENSe JPOWerSEMICLA rc 244 TEE ET GE 202 SENSE SWESp TIME cic t de Winall HE Pte aec daa eae 202 EISE WR lee le EE 215 SENSE TRACKING IQMCOM Pi EE 215 EIST WR NEE 216 EISE WR ele 216 SENSe TRACking PlLots EIB WR e RTE SENSesn gt DEMod FORMatSIGSYMbol cion aE A A 230 SENSe lt n gt iPOWef SEM 243 ABOR Liar HEN 260 CAL Culate LIMt BURSEALE ai a 237 SA e lee EE Te 276 CALCulate LIMit BURSt EVM ALL MAXimum CAL Culate LIMit BURSt EVM ALL MAXimum RES Ult AA 276 CAL Culate IM BURGCEVMALUTAVERaoel corran nc nan n cc rannnncannnnns 238 CAL Culatel IMC BUIRGCEVMALLTAVERaoelRE Gut 276 CAL Culate LIMi BURStEVM DATA MAXIMUM sa ote ca Eee cote t e etre esee c cae Ere 238 CAL Culate IM BURGCEVM DATA MAXImum RE Gut 276 CALCulate EIMIEBURSEEVM DATA AVERAagg6 ioco tene inne CALCulate LIMit BURSt EVM DATA AVERage RESult CAL Culate IM BURGCEVM PI ot MA Nimum eene nn ener ennnnen nennen nenne nnn CAL
76. 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 n next to the keyword 11 2 4 11 2 5 11 2 6 Introduction If you don t quote a suffix for keywords that support one a 1 is assumed Example DISPlay WINDow lt 1 4 gt ZOOM STATe enables the zoom in a particular mea surement window selected by the suffix at WINDow DISPlay WINDow4 ZOOM STATe ON refers to window 4 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 1 42 200M STATe DISPlay ZOOM STATe ON enables the zoom in window 1 no suffix DISPlay WINDow4 ZOOM STAT
77. is defined as a percentage of the currently displayed value range on the x axis or y axis Example The currently displayed value range on the y axis is 0 to 100 The upper limit is fixed by a maximum of 100 The lower hysteresis range is defined as 10 to 10 If the minimum value in the current measurement drops below 10 or exceeds 10 the y axis will be rescaled automatically for example to 10 100 or 10 100 respec tively Upper HIU If the maximum value in the current measurement exceeds the speci fied range the x axis or y axis is rescaled automatically Lower HIL If the minimum value in the current measurement exceeds the speci fied range the x axis or y axis is rescaled automatically Remote command DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis LOWer UPPer onpage 255 DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis LOWer LOWer on page 256 DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis UPPer LOWer on page 256 DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis UPPer UPPer on page 256 Minimum Maximum Defines the minimum and maximum value to be displayed on the x axis or y axis of the specified evaluation diagram For automatic scaling with a fixed range see Auto Fix Range the minimum defines the fixed lower limit the maximum defines the fixed upper limit Remote command DISP
78. limit values for the parameters determined by the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 12 all in one step To define individual limit values use the individual CALCulate lt n gt LIMit lt k gt BURSt commands Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Note that the units for the EVM and gain imbalance parameters must be defined in advance using the following commands e UNIT EVMon page 275 e UNIT GIMBalance on page 275 Parameters Limits The parameters are input or output as a list of ASCII values separated by in the following order average CF error max CF error average symbol clock error max symbol clock error average UO offset lt maxi mum UO offset average EVM all carriers max EVM all car riers gt average EVM data carriers max EVM data carriers average EVM pilots max EVM pilots CALCulate LIMit BURSt EVM ALL AVERage Limit 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 For details on the EVM results and the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 12 Parameters Limit numeric value in dB The unit for the EVM para
79. never finish and the remote channel to the R amp S FPS is blocked for further commands In this case you must inter rupt processing on the remote channel first in order to abort the measurement To do so send a Device Clear command from the control instrument to the R amp S FPS on a parallel channel to clear all currently active remote channels Depending on the used interface and protocol send the following commands e Visa viClear Now you can send the ABORt command on the remote channel performing the mea surement Example ABOR INIT IMM Aborts the current measurement and immediately starts a new one Example ABOR WAI INIT IMM Aborts the current measurement and starts a new one once abortion has been completed Usage Event SCPI confirmed Starting a Measurement 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 118 INITiate lt n gt CONTinuous State This command controls the measurement mode for an individual measurement chan nel Note that in single measurement mode you can synchronize to the end of the mea surement with OPC OPC or WAI In continuous measurement mode synchroniza tion to the end of the measurement is not possible Thus it is not recommended that you use continuous measurement mode in remote control as results like trace data or markers are on
80. 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 Triggered Measurements Frame 1 Frame 2 Holdoff Fig 4 10 Effect of the trigger holdoff See Trigger Holdoff on page 111 4 9 5 Trigger Synchronization Using the Master s Trigger Output For MIMO measurements in which the data from the multiple antennas is captured simultaneously by multiple analyzers see Simultaneous Signal Capture Setup on page 114 the data streams to be analyzed must be synchronized in time One pos sibility to ensure that all analyzers start capturing UO data at the same time is using the master s trigger output functionality The R amp S FPS has variable input output connectors for trigger signals If you set the master s TRIGGER 2 INPUT OUTPUT connector to device triggered output and con nect it to the slaves trigger input connectors the master R amp S FPS sends its trigger event signal to any connected slaves The slaves are automatically configured to use the trigger source External The master itself can be configured to use any of the fol lowing trigger sources External e UO Power e IF Power e RF Power e Power Sensor 4 9 6 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 mult
81. not of interrest it is now maintained in order to show the different gains in the transmission matrix elements Nevertheless the limit lines are still symmetric to the mean trace individually for each element of the trans mission matrix By default full MIMO equalizing is performed by the R amp S FSW WLAN application However you can deactivate compensation for crosstalk see Compensate Crosstalk MIMO only on page 123 In this case simple main path equalizing is performed only for direct connections between Tx and Rx antennas disregarding ancillary trans 4 4 4 5 Channels and Carriers mission between the main paths crosstalk This is useful to investigate the effects of crosstalk on results such as EVM 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 80 Some of these carriers can be used active carriers others are inactive e g guard carriers at the edges The channel can then be determined using the active carriers as known points inactive carriers are interpolated Recognized vs Analyzed PPDUs A PPDU in a WLAN signal consists of the following parts For IEEE 802 11n see also figure 4 4 Preamble Information required to recognize the PPDU within the signal for example training fields e Sig
82. options 80 100 120 140 160 180 200 EN p NN E UN EE A Y A Output sample 10000 rate fou MHz Fig 1 1 Relationship between maximum usable I Q bandwidth and output sample rate with and with out bandwidth extensions A 1 4 R amp S FPS without additional bandwidth extension options 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 A 1 5 A 1 6 Q Data File Format iq tar R amp S FPS with option B40 UO 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 FPS with activated option B160 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 A 2 Restrictions The optional bandwidth extension R amp S FPS B160 can not be activated if any of the fol lowing conditions apply e R amp S FPS firmware versions previous to 1 20 For center frequencies larger than 7 GHz e With any trigger except for an external trigger UO Data File Format iq tar UO data is packed in a file with the extension iq tar An ig tar file contains UO data in binary format toge
83. 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 211 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 210 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 from 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 210 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 synchron
84. p 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 j p This description gives a rough view of the signal processing when using the R amp S FPS WLAN application with the IEEE 802 11a g OFDM j p standards Details are disre garded in order to provide a concept overview Abbreviations au symbol at symbol of subcarrier k EVM error vector magnitude of subcarrier k EVM error vector magnitude of current packet 9 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 Kmoa modulation dependent normalization factor amp relative clock error of reference oscillator Nk subcarrier of symbol e Block Diagram for Multicarrier Measurements essen 57 e Literature on the IEEE 802 11a Gtandard 64 Block Diagram for Multicarrier Measurements A diagram of the significant blocks when using the IEEE 802 11a g OFDM j or p standard in the R amp S FPS WLAN application is shown in figure 4 1 First the RF signal is downconverted to the IF frequency fr The resulting IF signal reit is shown on the lef
85. page 119 CONFigure WLAN ANTMatrix STATe lt state gt State This remote 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 115 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 114 CONFigure WLAN MIMO CAPTure lt SignalPath gt Specifies the signal path to be captured in MIMO sequential manual measurements Subsequently use the INITiate lt n gt IMMediate command to start capturing data Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt SignalPath gt Example Manual operation RX1 RX2 RX3 RX4 RX5 RX6 RX7 RX8 For details see Manual Sequential MIMO Data Capture on page 117 RST RX1 CONFigure WLAN MIMO CAPTure RX2 INIT IMM Starts capturing data from the receive antenna number 2 See Single Cont on page 118 CONFigure WLAN MIMO CAPTure BUFFer lt SignalPath gt Specifies the signal path to be captured in MIMO sequential manual measurements and immediately starts capturi
86. 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 115 CONFigure WLAN ANTMatrix ANTenna lt Analyzer gt Antenna This remote control command specifies the antenna assignment of the receive path Parameters lt Antenna gt 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 ANT4 ANT2 Analyzer number 42 measures antenna no 2 Manual operation See Assignment on page 115 CONFigure WLAN ANTMatrix SOURce ROSCillator SOURce Coupling This remote control command determines whether the reference frequency for the master and slave devices in a simultaneous MIMO setup are coupled or not Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Coupling gt Coupling mode AUTO Slaves set to the same external reference source as master Use an R amp S 211 trigger box to send to the same trigger to all devices see TRIG SEQ SOUR TUN EXTernal Slaves reference source is set to external Configure a trigger output from the master see OUTPut TRIGger lt port gt OTYPe on page 209 OFF Slaves reference source is set to internal RST EXT Example CONF WLAN ANTM SOUR ROSC SOUR AUTO Manual operation See Reference Frequency Coupling on
87. 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 lt n gt IMMediate command Usage Event Manual operation See Channel Power ACLR on page 51 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 lt n gt IMMediate command Usage Event Manual operation See Spectrum Emission Mask on page 52 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 lt n gt IMMediate command Usage Event Manual operation See Occupied Bandwidth on page 53 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance CONFigure BURSt STATistics C CDF 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 INITiate lt n gt IMMediate command Usage Event Manual operation See CCDF on page 54 11 5 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance The following co
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89. 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 46 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 218 CONFigure WLAN GTIMe AUTO TYPE on page 219 CONFigure WLAN GTIMe SELect on page 220 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 5 3 9 3 Demodulation IEEE 802 11b g DSSS The following settings are available for demodulation of IEEE 802 11b or g DSSS sig nals Demodulation PPDUs to Analyze uut snam Meas only the specified PPDU Format T OVI Gi inl Meas onl
90. settings available to configure measure ments and analyze results with their corresponding remote control command chapter 7 1 Import Export Functions on page 157 Description of general functions to import and export raw l Q measurement data chapter 8 How to Perform Measurements in the WLAN Application on page 161 The basic procedure to perform each measurement and step by step instructions for more complex tasks or alternative methods chapter 10 Optimizing and Troubleshooting the Measurement on page 171 Hints and tips on how to handle errors and optimize the test setup chapter 11 Remote Commands for WLAN Measurements on page 174 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 FPS User Manual Programming examples demonstrate the use of many commands and can usually be executed directly for test purposes chapter A Annex Reference on page 313 Reference material List of remote commands Alpahabetical 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 FPS 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 Man
91. specified file Manual operation See UO Export on page 158 11 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 for RF measurements General result analysis settings concerning the trace markers lines etc for RF mea surements 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 FPS User Manual Mathers cc Ec 299 e Zooming Into the Display tcn tt ret dtu ert eae 300 Analysis 11 10 1 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 mo STATe 2 222 irent pere vog uua a SEENEN pcne aas 299 AN E A a EE aA R daaa 299 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 MARKe
92. switch to Manual mode Remote command TRIG SEQ LEV POW AUTO ON see TRIGger SEQuence LEVel POWer AUTO on page 206 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 205 TRIGger SEQuence LEVel IQPower on page 205 TRIGger SEQuence LEVel EXTernal port on page 205 TRIGger SEQuence LEVel RFPower on page 206 Drop Out Time Trigger Source Settings Defines the time the input signal must stay below the trigger level before triggering again WLAN IQ Measurement Modulation Accuracy Flatness Tolerance For more information on the drop out time see chapter 4 9 3 Trigger Drop Out Time on page 84 Remote command TRIGger SEQuence DTIMe on page 204 Trigger Offset Trigger Source Settings Defines the time offset between the trigger event and the start of the measurement For more information see chapter 4 9 1 Trigger Offset on page 83 offset gt 0 Start of the measurement is delayed offset 0 Measurement starts earlier pre trigger Remote command TRIGger SEQuence HOLDoff TIME on page 204 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
93. teu dus Configuration remote x ele le lgl e X es 91 Constellation cirio tentent trt 26 Constellation vs carrier 28 Diagram me 200 Evaluated data EVM vs carrier 229 EVM vs chip EECH EVIMVS SYMDO coccion ia 30 FFT SDGCIFUI EE 31 Freq Error vs Preamble E Gain Imbalance vs Carrier 1009 Group Delay 2 84 Magnitude Capture 4 95 Marker table 2400 Peal Eisner rats 56 Phase Error vs Preamble eeesssssess 37 Phase Tracking 197 PvT Falling Edge 41 PvT Full PPDU 499 PvT Rising Edge 40 Quad Error vs Carrier we 42 Result SUMMAN nice 55 Result Summary Detailed ssussse 43 Result Summary Global i 44 Result Summary items 143 Result Summary items remote 252 see also Evaluation methods ffe Signal Field ne mu 46 Signal Field Hi SA RE 38 Spectrum Flatness cerneret eres 49 WULAN WEE 21 Result Summary Detailed result display ssess 43 Evaluation method 4 55 Global result display 44 Items to display 143 Items to display remote 252 Result display nis OD Trace data oiim n ren aee rane 287 Results TEE AM EVM AM PM Bitstream CODE etie Constellation vs carrier eeseese
94. the lower limit of the upper hysteresis interval If the maximum value in the current measurement drops below this limit the x axis or y axis is rescaled automatically For details see Hysteresis Interval Upper Lower on page 148 Parameters lt Value gt Percentage of the currently displayed value range on the x axis or y axis Example DISP WIND2 TRAC Y AUTO HYST UPP LOW 25 Manual operation See Hysteresis Interval Upper Lower on page 148 DISPlay WINDow lt N gt TRACe lt t gt X SCALe AUTO HYSTeresis UPPer UPPer lt Value gt DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis UPPer UPPer lt Value gt For automatic scaling based on hysteresis this command defines the upper limit of the upper hysteresis interval Ifthe maximum value in the current measurement exceeds this limit the x axis or y axis is rescaled automatically For details see Hysteresis Interval Upper Lower on page 148 Configuring the Result Display Parameters lt Value gt Percentage of the currently displayed value range on the x axis or y axis Example DISP WIND2 TRAC Y AUTO HYST UPP UPP 20 Manual operation See Hysteresis Interval Upper Lower on page 148 DISPlay WINDow lt n gt TRACe lt t gt X SCALe AUTO MEMory DEPTh lt NoMeas gt DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO MEMory DEPTh lt NoMeas gt For automatic scaling based on memory this value defines the number lt x gt of previous
95. 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 226 and SENSe DEMod FORMat BANalyze on page 225 Manual operation See PPDU Analysis Mode on page 124 SENSe DEMod FORMat MCSindex Index 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 Index 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 Mode 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 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 fo
96. trigger port 1 trigger port 1 TRIG IN connector on rear panel 2 trigger port 2 TRIG AUX connector on rear panel Parameters lt TriggerLevel gt Range 0 5V to 35V RST 1 4V Example TRIG LEV 2V Manual operation See Trigger Level on page 110 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 110 TRIGger SEQuenceJ 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Example TRIG LEV Top 30DBM Manual operation See Trigger Level on page 110
97. unit Hz gt 6 5e 006 lt Clock gt UO Data File Format iq tar 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 DataFilename xyz complex float32 DataFilename lt UserData gt lt UserDefinedElement gt Example lt UserDefinedElement gt lt UserData gt lt PreviewData gt lt PreviewData gt lt RS_IQ TAR FileFormat gt Element Description RS IQ TAR File Format The root element of the XML file It must contain the attribute fileFormatVersion 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 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
98. upper right corner is the end point of the system Range O 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 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 11 11 Status Registers The WLAN application uses the standard status registers of the R amp S FPS depending on the measurement type However some registers are used differently Only those differences are described in the following sections User Manual 1176 8551 02 06 301 Status Registers For details on the common R amp S FPS status registers refer to the description of remote control basics in the R amp S FPS User Manual E RST does not influence the status registers e The STATus QUEStionable SYNC Register 302 e Querying the Status EE 303 11 11 14 The STATus QUEStionable SYNC Register The STATus QUEStionable 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 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 SYN
99. 0 PNOISE Phase Noise VSA R amp S FPS K70 DDEM VSA 3GPP FDD BTS R amp S FPS K72 BWCD 3G FDD BTS 3GPP FDD UE R amp S FPS K73 MWCD 3G FDD UE TD SCDMA BTS R amp S FPS K76 BTDS TD SCDMA BTS TD SCDMA UE R amp S FPS K77 MTDS TD SCDMA UE cdma2000 BTS R amp S FPS K82 BC2K CDMA2000 BTS cdma2000 MS R amp S FPS K83 MC2K CDMA2000 MS 1xEV DO BTS R amp S FPS K84 BDO 1xEV DO BTS 1xEV DO MS R amp S FPS K85 MDO 1xEV DO MS WLAN R amp S FPS K91 WLAN WLAN LTE R amp S FPS K10x LTE LTE Note the default channel name is also listed in the table If the specified name for a new channel already exists the default name extended by a sequential number is used for the new channel INSTrument REName lt ChannelName1 gt lt ChannelName2 gt This command renames a measurement channel Parameters lt ChannelName1 gt String containing the name of the channel you want to rename Selecting a Measurement lt ChannelName2 gt String containing the new channel name Note that you can not assign an existing channel name to a new channel this will cause an error Example INST REN Spectrum2 Spectrum3 Renames the channel with the name Spectrum2 to Spectrum3 Usage Setting only INSTrument SELect lt ChannelType gt 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 CREat
100. 0MHz 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 125 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 226 Parameters Format RST QAM64 Example SENS DEMO FORM BAN BPSK6 Manual operation See PPDU Format to measure on page 124 See PSDU Modulation to use on page 125 See PSDU Modulation on page 126 See PPDU Format to measure PSDU Modulation to use on page 131 See PPDU Format on page 132 Table 11 4 Modulation format paramet
101. 1 N o 2 J IMAG f6v 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 x 1Y A 81 x 2 REAL 0 6 f v 0 Gain imbalance I branch 4 18 1S g y IMAG to o Gain imbalance Q branch 4 19 Finally the mean error vector magnitude can be calculated with a non data aided cal culation E ps qe mE PA REAL v i g T uc Mackie go da 0 v 0 Verr v v di B a 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 FPS K91 Measurement Basics i REAL v 6 9 IMAG r v a do i BP 68 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 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 achieve
102. 215 5 3 9 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 95 e Demodu lation IEEE 02 1 1a g OFDM j p rr ri 123 e Demodulaton EEE 902 1186 eundi erede tto REENEN EEN 126 e Demodulatiori IEEE 802 11b q DSSS ue teet a 131 e Demodulation IEEE 902 11n ne eie rana 132 e Demedulation MIMO IEEE 802 118 Bh re tertie 136 5 3 9 1 Demodulation IEEE 802 11a g OFDM j p The following settings are available for demodulation of IEEE 802 11a g OFDM j p signals WLAN IQ Measurement Modulation Accuracy Flatness Tolerance mm Demodulation PDUs to Analyze PSDU Modulation Coded OFOM Coded OF DM BPSK r 1 2 Rate is indicated in Signah Guard Interval Length 16 samples Fig 5 2 Demodulation settings for IEEE 802 11a g OFDM j or p standard PPDU Analysis EE 124 PPDU Format to megsslile iter peer eren tat Sie Re beer n rte Ce en SE deed ERE 124 Channel Bandwidth to measure CDW sess 125 PSDU Bee TE Leuken EEN 125 PSDU Modulstioh aedi iie diti eet Ee reae i etre cote dada Pieve 126 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
103. 273 FETCHEBURStMGPowe AVERA QB ae ee ae nth nn enne en nennt sns s ss ainiaan 273 FETCHBURSEMCOPOWe MA MM a A ETEN 273 FETCH BURSEMCPO Wer MINIMUM siarane raaa an aaa na adana iR 273 FETCHEBURStEPAY Load AVER QE P eisni puniani ped det iaia aida 273 FETCHBURStPAY Load MINIMU A erre en eor den e venga 273 FETCHhB RSEPAYEoad d MAXIBIUITI 5 5 2 2 B ERIT Ie e rei PRISE RIED shaded E MPa Y RO eee 273 FETOIBURSEPEANLAVERAQS ais de Ene e truci See 273 FETCH BURStPEAK MINIMUM ao cocci n agna dn npa 273 FETChiBURSEPEAKIMIAXIIIBIINIE coa 273 ag ler ug E E 273 FETCh BURG bbREamble MihNimum aaa iaaa apaiia aaan a aiana 273 FETCH BURSEPREaMmBIE MAXIMUM occiso ariadna 273 FETChBURSGQUADOTSEEAV ERAGE Lucia EES aa a asia ENEE 274 FETCh BURStQUADoffset MAXIMUM crrr reana n auaina naana aiaa i danii 274 FETOh BURSEQUADotffseEMINIImUlYI urat SEENEN ALAE REEE 274 FETCh BURSERMS AVERage coordina aiii 274 FETGCIELBURSERMS MAXIDWETI 5x caras cu ta euo XY Ee DRE e XR YE caen E SX n Cura p aen cer gedra qus 274 FEICHIBURSERMS MIBIIUERE ioo tasa tpa tere nat a E er a bua ERU by aa E ANEREN TRY NEE 274 FETCINBURSES Y MBOle mor A VERA icon iara a aiaa aA aaa 274 FETCHIBURSESYMBOol rrorMAXIImUE 223r aida nas ERR ERTE 274 FETCh BURG SvMolerror MiNmmum nehanana a a aeaiia 274 FETCh BURSCTEAELAVEIRSOGY iore daretur A a A aaa dda dataa 274 FETCh BURSETFEALBEMJAXINIITIT coca 274 FETGIBURSE TPEALEMIBNIF UE 5
104. 33 Format default rte e 92 Format remota ees am deett 225 226 Guard interval length IEEE 802 11 n ac 130 136 218 219 220 Eire 267 l evel erTOIS tes cce iere enisi eds 122 215 216 Maximum length remote ssseese 236 Minimum length remote ssseses 236 Modulation 125 226 Modulation IEEE 802 11 a 126 132 Modulation IEEE 802 11 n ac 128 134 Modulation remote AA 306 Ness IERE 802 11 n ent 135 218 NS ua 129 Nsts IEEE 802 11 ac 129 229 Number to analyze reete 233 Number to analyze remote ssssssus 233 Payload length 140 142 Payload length remote sssssssss 231 Phase drift EE 122 216 Physical channel 2 eege eege eege Ce 12 14 Pilots 2 122 216 POWGM p M 12 Power search 120 214 Recognized 12 14 79 SeleCtiligi EE 284 Selecting remote ANE 284 Signal field tii 46 124 127 133 228 SA tette tete 266 STBC IEEE 802 11 ac n 129 135 222 Synchronization MIMO seen 115 TING D e 122 217 Total analyzed 2 1 one AE 12 14 ULT H 79 PPDUs Evaluation range L ck E Preamble Channel estimation UNITS d rere RA Preamplifier A tme rer tee eren co 105 src m t 105 Preset
105. 4 14 Retrieving Results The number of repeating groups that are returned is equal to the number of measured symbols Each EVM value is returned as a floating point number expressed in units of dBm Supported data formats see FORMat DATA on page 283 ASCii REAL TRACE1 Minimum EVM values TRACE2 Mean EVM values TRACE3 Maximum EVM values These results are not available for single carrier measurements IEEE 802 11b g DSSS FFT Spectrum Returns the power vs frequency values obtained from the FFT This is an exhaustive call due to the fact that there are nearly always more FFT points than I Q samples The number of FFT points is a power of 2 that is higher than the total number of UO samples Le number of FFT points round number of l 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 TRACE1 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 11 9 4 15 11 9 4 16 11 9 4 17 Ret
106. 400 000 000 00 62 z a per BI dm Lev 20 00 fim GA Frec d Freq A ALC Auto B ALC Auto iv On on User Init bd iv On Append ween pes 10 Select Spatial Streams 2 and Space Time Streams 2 Return to the IEEE 802 11n WLAN A dialog Measurement Example Setting up a MIMO measurement A Feel 2 400 000 000 Den es ka sel 20 D gn tev 20 00 iv B 4 2 400 000 000 00 crz z E er 20 00 8m ted 20 00 feam A ALC Auto B ALC Auto 802 11n A 11 Check Configure Baseband B from Baseband A This will generate a IEEE 802 11n conform Tx 2 signal for path B of the SMU 12 Toggle the State to On and make sure RF A Mod A and RF B Mod B are switched on Measurement Example Setting up a MIMO measurement A rd 2 400 000 000 00 s z pee 937 dm el 20 00 m 7 B Fs 2 400 000 000 00 ferz 9 37 dm Lev SES A ALC Auto B ALC Auto i 1 Restart 2 Restart n VQ OUT 3 Restart 4 Restart Q Patha 9 Paths BB Input BERT On Vv TC On BERT 1 Restart i o 2 Restart 3 Restart Marker E 13 Using the Graphics Power Spectrum display shows the power spectrum for both antennas 14 Now set up the spectrum analyzer with the R amp S FPS K91n option to perform the WLAN MIMO measurements Start the R amp S FPS K91n application 15 Select Standard IEEE 802 11n MIMO Set the RF Frequency the DUT is transmitting 16 Set Trigg
107. 89 Remote commands exclusive to retrieving trace results POD EE 283 SENSE BURSE SELEG ncra t tert credet etd qu rp edat cett rr eat geste kdo e orav apt add 284 SENS amp JBURSESELecEU STATO erede a A v Y ARR AD 284 TRAD EE 284 TRADE DATAS EE 286 TACTO DATA MEMON iude Mute A xe xe ete etus 286 FORMat DATA Format This command selects the data format that is used for transmission of trace data from the R amp S FPS to the controlling computer Note that the command has no effect for data that you send to the R amp S FPS The R amp S FPS automatically recognizes the data it receives regardless of the format Parameters Format ASCii ASCii format separated by commas 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 FPS 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
108. 95 NEC 715 cr 295 e Magnitude Captures cecidere iaa 296 e Phase TItaokllg eoe a 296 e Power vs Time Full Burst and Rising Falling Data 296 e SIMA A EE 297 e Spectrum EE 297 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 191 R amp S FPS K91 Remote Commands for WLAN Measurements 11 9 4 5 User Manual 1176 8551 02 06 IEEE 802 112 j 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 Q
109. A signal gen erator typically outputs the UO data at a rate that equals the clock frequency If the UO 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 e complex Complex number in cartesian format i e and Q values interleaved and Q are unitless real Real number unitless polar Complex number in polar format i e magnitude unitless and phase rad values interleaved Requires DataType float32 or f1oat64 DataType Specifies the binary format used for samples in the UO data binary file see DataFilename element and chapter A 2 2 I Q Data Binary File on page 320 The following data types are allowed int8 8 bit signed integer data int16 16 bit signed integer data int32 32 bit signed integer data float32 32 bit floating point data IEEE 754 float64 64 bit floating point data IEEE 754 UO Data File Format iq tar Element Description ScalingFactor Optional describes how the binary data can be transformed into values in the unit Volt The binary 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 mag
110. AM and 64 QAM constellation bit encoding 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 corresponds to the number of data subcarriers plus the number of pilot subcariers Nsp Nsp in remote mode As opposed to the graphical Bitstream results the DC and NULL carriers are not avail able in remote mode Standard CBW in Nsp Nsp Nsr MHe Number of data Number of pilot Total number subcarriers subcarriers of subcarriers Ngp Nsp IEEE 802 11a p 5 48 4 52 IEEE 802 11a j p 10 48 4 52 IEEE 802 11a j 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
111. AN Measurements WLAN measurements require a special application on the R amp S FPS R amp S FPS K91 The measurement is started immediately with the default settings o These are basic R amp S FPS commands listed here for your convenience INSTramentoREate DUPLIGale eite e eet tee ener ett eaten opened 180 INSTr ment CREate NEW aires t hrec decora ta 180 INSTrument CREate REPLace 2 eei eeieilesae sanie esa esa nasa aA aaa dn ARR D BAR anana Enaaak Sea 181 Leger RE 181 INS Tr mebit L T9 EE 181 INSTr mentRENAm 2 riri dat reote SEENEN nee pda EE a SEN 182 INS ge Diet DE DEE 183 SYSTemiPRESeEOHANnsSIEEXEQCUE EE 183 INSTrument CREate DUPLicate This command duplicates the currently selected measurement channel i e creates a new measurement channel of the same type and with the identical measurement set tings The name of the new channel is the same as the copied channel extended by a consecutive number e g Spectrum 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 measurement channels you can configure at the same time depends on available memor
112. ASS a ce ete tee exe mex ema cene de ena dude A 244 SENSe lt n gt POWer SEM Type This command sets the Spectrum Emission Mask SEM measurement type Parameters Type 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 306 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 11 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 20009 40 2 A 40M 24G Figure 20 18 Transmit spectral mask for a 40 MHz channel IEEE 802 11n 2009 20M 5G IEEE Std 802 11n 2009 IEEE 2009 20 5 Figure 20 17 Transmit spectral mask for 20 MHz transmission IEEE 802 11n 2009 40M 5G IEEE Std 802 11n 2009 IEEE 2009 40 5 Figure 20 18 Transmit spectral mask for a 40 MHz channel Configuring the Result Display 11 7 Ma
113. C 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 D Each active channel uses a separate STATus QUEStionable SYNC register Thus if Table 11 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 Auto 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 Status Registers Bit No Meaning 7 14 These bits are not used 15 This bit is always 0 11 11 2 Querying the Status Registers 11 11 2 1 The following comman
114. Ce lt t gt X SCALe MINimum Min DISPlay WINDow lt n gt TRACe lt t gt Y SCALe MINimum Min Defines the maximum value to be displayed on the x axis or y axis of the specified evaluation diagram For automatic scaling with a fixed range see DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO FIXed RANGe on page 255 the maximum defines the fixed upper limit Parameters lt Min gt Example DISP WIND2 TRAC Y SCAL MIN 20 Manual operation See Minimum Maximum on page 148 DISPlay WINDow lt n gt TRACe lt t gt X SCALe PDIVision lt State_1 gt lt State_2 gt lt State_2 5 State 5 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe PDIVision lt Multiple gt lt Multiple gt Determines the values shown for each division on the x axis or y axis in the specified window One or more multiples of 10 can be selected For details see Scaling per division on page 149 Parameters lt Multiple gt 1 0 2 0 2 5 5 0 If enabled each division on the x axis or y axis displays the selected multiple of 10 RST 1 0 5 0 Example DISP WIND TRAC Y SCAL PDIV 2 0 2 5 Multiples of 2 0 and 2 5 are displayed on the x axis or y axis Manual operation See Scaling per division on page 149 11 8 Starting a Measurement When a WLAN measurement channel is activated on the R amp S FPS a WLAN IQ mea surement Modulation Accuracy Flatness and Tolerance see chapter 3 1 WLAN IO Measurement
115. 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 11 Remote Commands for WLAN Measure ments The following commands are required to perform measurements in the R amp S FPS WLAN application in a remote environment It is assumed that the R amp S FPS has already been set up for remote control in a net work as described in the R amp S FPS User Manual Note that basic tasks that are independant of the application are not described here For a description of such tasks see the R amp S FPS User Manual In particular this includes e Managing Settings and Results i e storing and loading settings and result data Basic instrument configuration e g checking the system configuration customizing the screen layout or configuring networks and remote operation Using the common status registers After an introduction to SCPI commands the following tasks specific to the WLAN application are described here e Common SUMXES eccirni ien ee ee e redd ea ER ee D da 174 9 itfodiJblofy s rtm det ra ia 175 e Acti
116. Culate IMC BURGCEVM PI ot MAXimum RE Gut 277 CALCulate EIMIEBURSECEVM PIEOtAVERage 2r eruta ette e reco tt eni erret 238 CALOCulate LIMit BURSt EVM PILot AVERage RESUIt sse 277 CAL Gulate LIMiBURSEFERROEMAXIM N E 239 CAL Culate ElMI BURSt FERRor MAXimuM RESUI aiii iden 277 CAL Culate LIMit BURSt FERRor AVERage CAL Culatel IMC BURGCEERRort AVERaoel RE Gu 277 CALCulate EIMIEBURSECIQOFfset MAXI tci ceu co A is 239 CAL Culate IM BURGrClIOOFrserMAvimum RE Gu 277 GALGulate EIMIEBURSEIQOFfset AVERage tnt trn tir tror er ten 239 CALGulate LIMit BURSCIQOFfset AVERaoeltRE Gut 277 CALOCulate LIMit BURSt SYMBolerror MAXimum esses enne nemen nnne nnns sene n cn se nent nenne 239 CALCulate LIMit tBURSt SYMBolerror MAXimum RESUIt esses eee 278 CALCulate LIMitBURSt SYMBolerror AVERage essent 239 CALOulate LIMit BURSt SYMBolerror AVERage RESUIt sese 278 CAL Culate EIMit ele CALOCulate n BURSI IMMediate sia CAL Culate lt n gt LIMit lt k gt ACPower ACHamnelRES UP eene eene 278 CAL Culate lt n gt LIMit lt k gt ACPower AL Ternate lt ch gt RESUlP uocccccocccinocccccoocnccnnonononnnncnonnnncnnnncnnnnnncnnannnncnnns 278 CAL Culatesn bIMitsko FAME oa oia 279 CALCulate n MARKer m FUNCtion POWer ssb RESUIt essen 280 CAL GCulatesns MARKOr EmTIo X E 282 GAL Culatesr MARKGESIP Y EE 299 CALCul
117. DU power dBm Mean PPDU power Crest factor dB The ratio of the peak power to the mean power of the signal also called Peak to Average Power Ratio PAPR MIMO Cross Power dB Center frequency error Frequency error between the signal and the current center frequency of the Hz R amp S FPS the corresponding limits specified in the standard are also indica ted The absolute frequency error includes the frequency error of the R amp S FPS and that of the DUT If possible the transmitterR amp S FPS and the DUT should be synchronized using an external reference See R amp S FPS User Manual Instrument setup External reference the limits can be changed via remote control not manually see chapter 11 5 9 Limits on page 237 in this case the currently defined limits are displayed here WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Parameter Symbol clock error ppm Description Clock error between the signal and the sample clock of the R amp S FPS 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 FPS and the DUT should be synchronized using an external reference See R amp S FPS User Manual gt Instrument setup gt External reference CPE Common phase error Stream parameters Pilot bit error rate EVM all carriers
118. 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 lt n gt IMMediate command Usage Event Manual operation See AM EVM on page 23 CONFigure BURSt AM PM IMMediate This remote control command configures the result display type of window 2 to be AM vs PM Results are only displayed after a measurement is executed e g using the INITiate n IMMediate command Usage Event 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 lt n gt 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 lt n gt IMMediate command Usage Event Manual operation See Constellation on page 26 Selecting a Measurement 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 measu
119. FPS K91 Measurements and Result Displays EH 2 FFT Spectrum ei CIW 16 0 MHz div 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 70 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 subwind OWS 3 FFT Spectrum Cem MSN Rx2 Rx3 Rx4 3 1Rx 1 16 0 MHz Span 160 0 MHz CF 5 775 GHz 16 0 MHz Span 160 0 MHz 3 4Rx4 Span 160 0 MHz CF 5 775 GHz 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 11 9 4 13 FFT Spectrum on page 295 Remote command LAY ADD 1 RIGH FSP see LAYout ADD WINDow on page 246 or CONFigure BURSt SPECtrum FFT IMMediate on page 188 Querying results TRACe lt n gt DATA see chapter 11 9 4 13 FFT Spectrum on page 295 SS UU User Manual 1176 8551 02 06 32 R amp S FPS K91 Measurements and Result Displays 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 2 Freq Error vs Preamble 91 Mine 2 Avge 3 Max 800 0 ns Remote command LAY ADD 1
120. Falling Edge on page 41 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 39 See PvT Rising Edge on page 40 See PvT Falling Edge on page 41 CONFigure BURSt QUAD QCARrier IMMediate This remote control command configures the result display type in window 2 to be Quadrature Error vs Carrier Results are only displayed after a measurement is execu ted e g using the INTTiate lt n gt IMMediate command Usage Event Manual operation See Quad Error vs Carrier on page 42 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 lt n gt IMMediate command Usage Event Manual operation See FFT Spectrum on page 31 CONFigure BURSt SPECtrum FLATness SELect lt MeasType gt This remote 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
121. G DSi actua aded tenu coca e tenax AOS 221 CONFigure WLAN SMAPping TX ch STReamsstreame esse eene 222 CONFigure WLAN SMAPping TX lt ch gt TIMeShift 0 cceceeeeeeeeeeeeeeeeeeeaeeeeaeaaaeaaeneteneneees 222 CONFOUre WLAN STBC RE e ak EE 222 SENSe JBANDWidth GHANnelAUTOTYPE es irae ERKENNEN 223 SENSe IDEMod FORMaEtBANAalyze 2 ote riada De e ENEE ENEE 225 SENSe DEMod FORMat BANalyze BTYPe AUTO TY PE nnns 226 SENSe DEMod FORMat BCONtent AUTO eicere tentent teni 228 SENSe TDEMod FORMatMOSIRUBX 2 2 2 note ette xt Renata ERE Sen 228 SENSe DEMod FORMat MCSindex MODE eeesssessessieseeee sienten nnne nnne nn nn 228 SENSeTBEMod FORMACNSESIDndex ua cote Edge 229 SENSe DEMod FORMaENSTSindex MODE wiv ccs cniin sides cesa eee ied ANEN 229 SENSe n DEMod FORMatSIGSymlbol 12 niano o aou nnn anro nn d de rh han kenn ennt 230 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 11n standard only 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 correspond
122. GHz Att 24 dB PA30 UE 5 0ms 0 05 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 17 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 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 246 Querying results TRACe lt n gt DATA see chapter 11 9 4 15 Magnitude Capture on page 296 User Manual 1176 8551 02 06 36 R amp S FPS K91 Measurements and Result Displays 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 8 Phase Error vs Preamble sl Mine2 Avg e 3 Max 800 0 ns Remote command LAY ADD 1 RIGH PEVP see You NDow on page 246 or on page 187 gu on page 187 Querying results sd see chapter 11 9 4 9 Error vs Preamble on page 293 Phase Tracking Displays the average phase tracking result per symbol in Radians This result display is not available for single carrier measurements IEEE 802 11b g DSSS 3 Phase Tracking FERNE
123. IND commands in the R amp S FPS see chapter 11 7 Configuring the Result Display on page 244 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 MMEMOM LOAD SEM STA FE nani id 306 SENS amp DEMod FORMatBANalyze B TYPE E 306 TRIGgern SEQuence MODE EE 307 MMEMory LOAD SEM STATe 1 Filename 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 FPS User Manual Remote commands for SEM measurements chap ter Parameters 1 Filename string Path and name of the xm1 file that contains the SEM setup information Example MMEM LOAD SEM STAT 1 sem_std WLAN 802 11a1802 lla 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 Commands for Compatibility Parameters lt PPDUType gt 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 sample rate
124. If the minimum and or maximum values of the current measurement exceed the minimum and or maximum of the lt x gt previous results the axis is rescaled The minimum and maximum value of each measurement are added to the memory After lt x gt measurements the oldest results in the memory are overwritten by each new measurement The number of results in the memory to be considered is configurable see Memory Depth Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO MODE on page 257 Auto Fix Range This command defines the use of fixed value limits None Both the upper and lower limits are determined by automatic scaling of the x axis or y axis Lower The lower limit is fixed defined by the Minimum Maximum settings while the upper limit is determined by automatic scaling of the x axis or y axis WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Upper The upper limit is fixed defined by the Minimum Maximum settings while the lower limit is determined by automatic scaling of the x axis or y axis Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO FIXed RANGe on page 255 Hysteresis Interval Upper Lower For automatic scaling based on hysteresis the hysteresis intervals are defined here Depending on whether either of the limits are fixed or not see Auto Fix Range one or both limits are defined by a hysteresis value range The hysteresis range
125. Le DIVisions Parameters lt State gt ON OFF 0 1 OFF 0 Switches the function off ON 1 Switches the function on RST 1 Example DISP WIND2 TRAC Y SCAL AUTO ON Configuring the Result Display Manual operation See Automatic Grid Scaling on page 147 DISPlay WINDow lt n gt TRACe lt t gt X SCALe AUTO FIXed RANGe lt AutoFixRange gt DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO FIlXed RANGe lt AutoFixRange gt This command defines the use of fixed value limits Parameters lt AutoFixRange gt NONE LOWer UPPer NONE Both the upper and lower limits are determined by automatic scaling of the x axis or y axis LOWer The lower limit is fixed defined by DISPlay WINDow lt n gt TRACe lt t gt Y SCALe MINimum DISPlay WINDow lt n gt TRACe t Y SCALe MAXimum while the upper limit is determined by automatic scaling of the x axis or y axis UPPer The upper limit is fixed while the lower limit is determined by automatic scaling of the x axis or y axis Example DISP WIND1 TRAC Y AUTO FIX RANG LOW DISP WIND1 TRAC Y MIN OdBm Sets the lower limit of the y axis to a fixed value of 0 dBm Manual operation See Auto Fix Range on page 147 DISPlay WINDow lt N gt TRACe lt t gt X SCALe AUTO HYSTeresis LOWer UPPer lt Value gt DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis LOWer UPPer lt Value gt For automatic scaling based on hysteresis this command define
126. MARK AKRNRRRRRRRRRU USER ERERRRRIS 79 4 5 Recognized vs Analyzed PPDUS eeeeseeeeeeenenenn nennen nnne nennen 79 4 6 Demodulation Parameters Logical Filters eee 80 4 7 Receiving Data Input and Providing Data Output eene 81 4 8 Preparing the R amp S FPS for the Expected Input Signal Frontend Parameters 82 49 Triggered Measurements eesseeeeeeeeeeeeenne nennen nnn nnne 83 4 10 WLAN I Q Measurements in MSRA Operating Mode eee 87 Ee te e 89 5 1 Multiple Measurement Channels and Sequencer Function 89 5 2 Display Configu ratiOR iiri Er ene RN ERRRNRR Ananda crono NARRA sana adas 91 5 3 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 91 5 4 Frequency Sweep Measurements een 151 MESI LI me an ds 156 7 WO Data Import and EXPO siste 157 7 1 Import Export FUNctiONS oococccccccccnnnnnonnonnoncnoncnnnnnnnnnnnnnnnnnnnnnnnennnnnnnnnnnnnnnnrnnerenennnnn 157 User Manual 1176 8551 02 06 3 R amp S9FPS K91 Contents 7 2 8 1 8 2 9 1 10 10 1 10 2 11 11 1 11 2 11 3 11 4 11 5 11 6 11 7 11 8 11 9 11 10 11 11 11 12 11 13 A 1 A 2 How to Export and Import UO Data ee REENEN 158 How to Perform Measurements in the WLAN Application 161 How to Determine Modulation Accur
127. MCS Index Nsts to use same type as first PPDU Nsts STBC Field Guard Interval L Modulation QPSK ength same type as first PPDU Data Rate Mb s 800ns GI 400ns GI 58 5 65 Fig 5 3 Demodulation settings for IEEE 802 11ac standard WLAN IQ Measurement Modulation Accuracy Flatness Tolerance PEDU Analysis MOS oi benda tede reb i e nete eee ben edu d 127 PPDU Format to easLile ue E EA A 127 Channel Bandwidth to measure CDW sss eene 128 MGS Index to TEE 128 esl qe eae 129 NSUS TO USB ier erc n decre eset teslis uode IR RISUS A RENE TUNER SENSERIT RN Eod OUR GE 129 I PEE 129 HH Ee Field iia 129 Table iNO ET 130 Guard Interval Length 130 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 228 PPDU Format to measure Defines which PPDU for
128. Modulation Accuracy Flatness and Tolerance on page 12 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 89 Starting a Measurement O Sates vacates estes M n 260 CALCulatesn BURSI IMMediale E 261 ll co ONT MUGS ci ade cpi YUAN RR b Dev 261 EINEN EE rende aria oe to roe tenere Rx ets ene tn rte 261 INiTiatesn gt e e e EE 262 INITlate nz GEOuencerJMMedate 262 INITiate lt n gt SEQuencer MODE occoocccccconnnccconnnnoconnnonnnnnonnnnnnononnnonnnnncnnnnnononnnnonnnncnnannnnnnns 262 INITiate lt n gt SEQuencenREFPRESHPALU ooo ion e n 263 AH RN 264 ABORt This command aborts the measurement in the current measurement channel and resets the trigger system To prevent overlapping execution of the subsequent command before the measure ment has been aborted successfully use the OPC or WAI command after ABOR and before the next command For details see the Remote Basics chapter in the R amp S FPS User Manual To abort a sequence of measurements by the Sequencer use the INITiate lt n gt SEQuencer ABORt command Note on blocked remote control programs If a sequential command cannot be completed for example because a triggered sweep never receives a trigger the remote control program will
129. Name gt This command deletes a measurement channel If you delete the last measurement channel the default Spectrum channel is activa ted Parameters lt ChannelName gt String containing the name of the channel you want to delete A measurement channel must exist in order to be able delete it Example INST DEL Spectrum4 Deletes the channel with the name Spectrum4 Usage Event INSTrument LIST This command queries all active measurement channels This is useful in order to obtain the names of the existing measurement channels which are required in order to replace or delete the channels 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 IQ IQ Analyzer2 Usage Query only Table 11 3 Available measurement channel types and default channel names in Signal and Spectrum Analyzer mode Application lt ChannelType gt Default Channel Name Parameter Spectrum SANALYZER Spectrum 1 Q Analyzer IQ IQ Analyzer Analog Demodulation R amp S FPS K7 ADEM Analog Demod GSM R amp S FPS K10 GSM GSM Noise R amp S FPS K30 NOISE Noise Phase Noise R amp S FPS K4
130. 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 226 and SENSe BANDwidth CHANnel AUTO TYPE on page 223 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 sample 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 226 and SENSe BANDwidth CHANnel AUTO TYPE on page 223 For new programs use SENSe DEMod FORMat BANalyze BTYPe AUTO TYPE MGRF SENSe BANDwidth CHANnel AUTO TYPE MB20 Manual operation See PPDU Format on page 132 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 207 commands for new remote control pro grams This command configures how triggering is to be performed Parameters Source 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 Programming Examp
131. O TYPE DL Manual operation See Guard Interval Length on page 130 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 130 CONFigure WLAN SMAPping MODE Mode This remote control command specifies the special mapping mode Parameters Mode DIRect SEXPansion USER DiRect direct SEXPansion expansion USER user defined Manual operation See Spatial Mapping Mode on page 137 CONFigure WLAN SMAPping NORMalise 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 tra
132. ODE o tede fene d roce ed 54 Constellation Result display rocosa ront enn vs carrier result display vs carrier trace data uniesienia vS Symbol trace data eege NEE Continue single sweep SOKE ete deret er oe eg 150 Continuous Sequencer feci 90 Continuous sweep SOfIK8y iere tbe RE Ere atts 150 Conventions SCGCPlicommnarids siii aed aee dea 175 Copying Measurement channel remote 180 Coupling Input remiote E 193 Crest EACIOE EE 12 Crosstalk A A 215 D Data acquisition Manual MIMO oreet noit MIMO capture method MIMO settings MSRA eiiis see Sigrial capturing E Data format aii s c 283 Data input Data output Data streams Mapping MIMO irt ep nd 138 Data symbols Estimating IEEE 802 11a g OFDM j p 62 INGIMDOF ee a Number of displayed aire ataca Default values Si E ER Demodulation Basica 80 Configuring i 123 Configuring remote a217 Dependencies iaa 80 Parameter Surinin mex neis 80 Settings MIMO 136 Diagram Ree 11 Diagrams Evaluation MOOG cesiones 55 Digital standard sissies sian notai 12 14 Channel bandwidths sssss 125 128 134 Default 2 Displayed Selecting Selecting remote Direc
133. Open icon in the tool bar For a description of the other functions in the Save Recall menu see the R amp S FPS User Manual MP m Borde 157 L AT ce tte Do Eh tei eerte ted tete Ee se as Pe Ho cts 158 EXPO ED EE 158 i o MMC C 158 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 FPS UO Analyzer and UO Input User Manual Remote command MMEMory LOAD IQ STATe on page 297 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 To store data permanently select an external storage locati
134. Options Max usable UO BW Required B option 40 MHz B40 160 MHz B160 A 1 2 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 MSRA operating mode In MSRA operating mode the MSRA Master is restricted to a sample rate of 600 MHz The figure 1 1 shows the maximum usable I Q bandwidths depending on the output sample rates A 1 3 Relationship Between Sample Rate Record Length and Usable UO Bandwidth Up to the maximum bandwidth the following rule applies Usable LO bandwidth 0 8 Output sample rate Regarding the record length the following rule applies Record length Measurement time sample rate Maximum record length for RF input The maximum record length that is the maximum number of samples that can be cap tured depends on the sample rate Table 1 1 Maximum record length Sample rate Maximum record length 100 Hz to 200 MHz 440 MSamples precisely 461373440 440 1024 1024 samples 200 MHz to 10 GHz 220 MSamples upsampling The figure 1 1 shows the maximum usable UO bandwidths depending on the output sample rates Sample Rate and Maximum Usable UO Bandwidth for RF Input Usable UO bandwidth UO bandwidths for RF input MHz HE EHE Activated option B160 160 150 A 110 100 Option B40 or deactivated option B160 H T sues EEE E E
135. PM See LAYout ADD WINDow on page 246 or CONFigure BURSt AM PM IMMediate on page 185 Querying results TRACe lt n gt DATA see chapter 11 9 4 2 AM PM on page 290 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 g DSSS User Manual 1176 8551 02 06 23 R amp S FPS K91 Measurements and Result Displays JEE 3 AM EVM 10 0 dBm Remote command LAY ADD 1 RIGH AMEV see LAYout ADD WINDow on page 246 or CONFigure BURSt AM EVM IMMediate on page 185 Querying results TRACe lt n gt DATA see chapter 11 9 4 3 AM EVM on page 290 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 b
136. 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 226 SENSe DEMod FORMat BANalyze on page 225 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 46 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 223 PSDU Modulation to use Specifies which PSDUs are to be analyzed depending on their modulation Only PSDUs using the selected modulation
137. Q OFFS 1GHZ Usage SCPI confirmed Manual operation See Frequency Offset on page 101 11 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 193 INPut IMPedance on page 194 e SENSe ADJust LEVel on page 240 Remote commands exclusive to amplitude settings CAL Gulatesm UNIT PO Wer eM EE 198 CONFigure POWGFUAB e DEE 198 CONFigure POWeEIECAUTOSGSWESbTIME 2c eet tee ntt ne tort rtt ertt ea 198 CONFigure POWerEXPeclediRE 2 rte a aa do ed cedes 199 DiSblavlfWiNDow nzTR ACectlSCALelRLEVel nnns 199 DiSblavlfWiNDow nzTR ACectzvltSCALelbRlEVelOEtzGet nenen er er rerrrrerene 199 INPUDAT TONUA T 199 INPUPAT KEE EN e ooo ai a Ea EAR 200 NEUES TI e em 200 INPUEEAT TIU e D 200 INPULEAT TAS TAM c 201 I Put GAINS KN 201 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 103 CONFigure POWer AUTO lt Mode gt This command is used to switch on or off automatic power l
138. Q UP AND SENS FREQ DOWN commands see SENSe FREQuency CENTer on page 195 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 101 SENSe FREQuency CENTer STEP AUTO lt State gt This command couples or decouples the center frequency step size to the span In time domain zero span measurements the center frequency is coupled to the RBW 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 101 Note In MSRA mode the setting command is only available for the MSRA Master For MSRA applications only the query command is available Parameters Offset Range 100 GHz to 100 GHz RST 0 Hz Example FRE
139. Q data BITStream Bitstream CMEMory Magnitude Capture CONStellation Constellation CVCarrier Constellation vs Carrier IEEE 802 11a g OFDM ac n p only EVCarrier EVCHip EVM vs Carrier IEEE 802 11a g OFDM ac n p only EVM vs Chip IEEE 802 11b and g DSSS only Configuring the Result Display Parameter value Window type EVSYmbol EVM vs Symbol IEEE 802 11a g OFDM ac n p only FSPectrum FFT Spectrum GDELay Group Delay IEEE 802 11a g OFDM ac n p only PFPPdu PvT Full PPDU 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 Window types for RF data 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 in the active mea surement channel from top left to bottom right The result is a comma separated list of values for each window with the syntax lt WindowName_1 gt lt Windowlndex_1 gt lt WindowName_n gt lt Windowlndex_n gt Return values lt WindowName gt Windowlndex Example Usage string Name of the w
140. R Rx1 Rx 3 1 Rx 1 Symb 1 64 6 Symb Symb 646 Symb 1 64 6 Symb Symb 646 Remote command LAY ADD 1 RIGH PTR see E IINDow on page 246 Or igure B on page 187 Querying results l See chapter 11 9 4 16 Phase Tracking on page 296 User Manual 1176 8551 02 06 37 R amp S FPS K91 Measurements and Result Displays JEE PLCP Header IEEE 802 11b g DSSS This result display shows the decoded data from the PLCP 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 I PLCP Header PSDU Length Signal Fig 3 18 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 Service Information in service field 00100000 Symbol clock state Modulation format Length extension Lock CCK bit state where Symbol clock state Locked Modula
141. R amp S9FPS K91 WLAN Measurements User Manual Caney im No QM L ed Poets hs ne a mr of Dn e Anak gt hand 2 Constellation Jn Estin En mation arier Carrier 259 N E Min d SD KM arrier m Symb 1 57 Symb Symb 570 1176 8551 02 06 ROHDE amp SCHWARZ Test amp Measurement User Manual This manual applies to the following R amp S9FPS models with firmware version 1 30 and higher R amp S FPS4 1319 2008K04 R amp S FPS7 1319 2008K07 R amp S FPS13 1319 2008K13 R amp S FPS30 1319 2008K30 R amp S FPS40 1319 2008K40 The following firmware options are described e R amp S FPS K91 WLAN 802 11a b g 1321 4191 02 e R amp S FPS K91ac WLAN 802 11ac 1321 4210 02 e R amp S FPS K91n WLAN 802 11n 1321 4204 02 e R amp S FPS K91p WLAN 802 11p 1321 4391 02 The firmware of the instrument makes use of several valuable open source software packages For information see the Open Source Acknowledgement on the user documentation CD ROM included in delivery Rohde amp Schwarz would like to thank the open source community for their valuable contribution to embedded computing 2015 Rohde amp Schwarz GmbH amp Co KG Muhldorfstr 15 81671 Munchen 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 trad
142. Referring to the IEEE 802 11a g OFDM j p measurement standard 6 the timing drift phase Mind is not part of the requirements Therefore the time tracking is not activated as the default setting of the R amp S FPS WLAN application see Timing Error Tracking on page 122 The time tracking option should rather be seen as a powerful analyzing 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 FIC9 is calculated This makes sense since the sequence fu 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 j p measurement standard 6 the compen sation 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 FPS WLAN application see Level Error Gain Tracking on page 122 Determining the error parameters log likelihood function How can the parameters above be calculated In this application the optimum
143. Remote command SENSe MSRA CAPTure OFFSet on page 242 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 FPS 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 SWAPiq on page 202 Suppressing Filter out Adjacent Channels IEEE 802 11a g OFDM ac j 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 interest Remote command SENSe BANDwidth RESolution FILTer STATe on page 202 5 3 5 2 Trigger Settings Trigger settings determine when the R amp S FPS 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 R amp S FPS K91 Configuration Signal Capture Trigger Source Trigger In Out MIMO Capture Trigger Source Free Run FS Z11 Trigger Connection Guideline for Trigger Unit FS Z11 Level Mode DUT Master Analyzer RF O
144. Remote command SENSe DEMod FORMat MCSindex on page 228 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 46 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 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 222 Extension Spatial Streams sounding Defines the PPDUs taking part in the analysis according to the Nes
145. SS uoneums3 Joqui s uoneulns3 uoneuins3 uoneuins3 ules eseug basy But uogewnsa peuonnied peuonnied peuonnied 1914 J9y sue uoneljsuo eubis sjueuuieduuj Ol WAS S19jouiBJed le Jo uoneuns 3 uajdwesey 1098 10 Gum 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 j2nM 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 S v the normalized oversampled power of the undisturbed reference signal N the observation length L the filter length Afv the variation parameters of the frequency offset Ad the variation parameters of the phase offset O Og the variation parameters of the IQ offset h i the coefficients of the transmitter filter 4 2 2
146. T 1 Example SENS BURS SEL STAT ON SENS BURS SEL 2 Results are based on the PPDU number 2 only Manual operation See Analyze this PPDU PPDU to Analyze on page 139 SENSe BURSt SELect STATe State If enabled the WLAN I Q results are based on one individual PPDU only namely the defined using SENSe BURSt SELect on page 233 If disabled all detected PPDUS in the current capture buffer are evaluated Parameters State ON OFF RST OFF Example SENS BURS SEL STAT ON SENS BURS SEL 2 Results are based on the PPDU number 2 only Manual operation See Analyze this PPDU PPDU to Analyze on page 139 SENSe DEMod FORMat BANalyze DBYTes EQUal State For IEEE 802 11b and g DSSS signals only Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 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 234 and SENSe DEMod FORMat BANalyze DBYTes MIN Parameters State ON OFF RST OFF Manual operation See Equal PPDU Length on p
147. T 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 FPS K91 Measurement Basics The physical channel is derived from the effective channel using the inverted spatial mapping matrix Q Hohy HQ 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 crosstalk from various sour ces for example e from the transmission paths inside the DUT from the connection between the analyzer and the DUT e from the analyzer itself The crosstalk from the
148. 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 Value Range 1 to statistic count 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 lt State gt 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 considered 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 WINDow lt n gt SELect Retrieving Results As opposed to the R amp S FPS
149. Te on page 201 INPut EATT AUTO on page 200 INPut EATT on page 200 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 96 Preamplifier option B22 B24 Input Settings Switches the preamplifier on and off If activated the input signal is amplified by 20 dB If option R amp S FPS B22 is installed the preamplifier is only active below 7 GHz If option R amp S FPS B24 is installed the preamplifier is active for all frequencies Remote command INPut GAIN STATe on page 201 Signal Capture Data Acquisition You can define how much and how data is captured from the input signal d MSRA operating mode In MSRA operating mode only the MSRA Master channel actually captures data from the input signal The data acquisition settings for the R amp S FSW WLAN application in MSRA mode define the application data extract See chapter 5 3 6 Application Data MSRA on page 119 For details on the MSRA operating mode see the R amp S FPS MSRA User Manual e General Capture Sets cucine tne e ree SEAN 106 TOJE SEN m 107 e MIMO Capture SStihigs et E ERE E eee eae 113 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance General Capture Settings The general capture settings define how much and which data is to be captur
150. UEStionable 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 bitis 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 Status Registers 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 11 11 2 5 Controlling the Negative Transition Part STATus 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 O 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 ch
151. URSt SPECtrum FLATness CSELect on page 253 5 3 11 3 AM AM Configuration For AM result displays some additional configuration settings are available e General AM AM Settings ier cere A e eR 145 e Scaling AM Result Displays iiis icece etie esses d tais edema aae so eaa canada 146 General AM AM Settings 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 22 The degree of this model can be specified in the Result Config dialog box for this result display Result Config Scaling X Scaling Y AM AM Polynomial degree for curve fitting GE e Ce Cl 3 AM AM User Manual 1176 8551 02 06 145 R amp S9FPS K91 Configuration The resulting regression polynomial is indicated in the window title of the result display Remote command 1 on page 254 Resulting coefficients 3 on page 270 Scaling AM Result Displays Scaling settings are available for the x axis or y axis of the following result displays e The available scaling settings and functions are identical for both axes but can be con figured separately J com Result Config Scaling X Scaling Y Automatic Grid Scaling Auto Fix Range Hysteresis Interval Upper HIU Hysteresis Interval Lower HIL n Memory Depth a Per Division are 10 multiples or 49 1 0 2 0 2 5 5 0 iaa 3 AM AM gt User Ma
152. UTPUT 1 RF INPUT NOISE SOURCE Trigger Level RF OUTPUT 2 TRIGGER INPUT RF OUTPUT 3 Slave Analyzer 1 RF OUTPUT 4 RF INPUT Trigger degen CT iota Slave Analyzer 2 RF INPUT Drop Out Time TRIG INPUT TRIG our TRIGGER INPUT TRIG OUT2 TRIG MANUAL Slave Analyzer 3 Slope ue m Falling J RF INPUT NOISE SOURCE TRIG OUTS 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 FPS are configured in a separate tab of the dialog box Trigger Source Trigger In Out Trigger 2 Input Output Type User Defined Pulse Length Send Trigger JL Trigger 3 For more information on trigger settings and step by step instructions on configuring triggered measurements see the R amp S FPS User Manual L Eso ds RE T ET 109 L External heet EE 109 ERE Mr 109 L 110 L L L L User Manual 1176 8551 02 06 108 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance aati RT RP 111 MET oo o arias 111 EE 111 EXON A MUR 111 L Capture A O 112 Ree 112 EST A M 112 o PS 113 L Pulse kengen 113 Eh 113 Trigger Source Settings The Trigger Source settings define when data is captured Trigger Source Trigger Source Settings Defines the trigger source If a trigger source other than Free Run is set TRG is displayed in the channel bar and t
153. User Manual 1176 8551 02 06 82 Triggered Measurements Attenuation To optimize the signal to noise ratio of the measurement for high signal levels and to protect the R amp S FPS from hardware damage provide for a high attenuation Use AC coupling for DC input voltage Amplification To optimize the signal to noise ratio of the measurement for low signal levels the sig nal level in the R amp S FPS 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 measurement with default settings the measurement is started immediately However 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 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 Hyst
154. 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 213 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 75 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 13 Sweep Settings on page 150 The dialog box shows a preview of the capture memories one for each RX antenna The PPDUs detected by the application are highlighted by the green bars R amp S9FPS K91 Configuration WLAN TS mm Signal Capture Trigger Source Trigger In Out MIMO Capture DUT MIMO Config 3 Tx Antennas MIMO Antenna Signal Capture Setup e 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 eed TT OO LEIT EICH Capture Memory Rx 1
155. VM PlLot MAXIMUM sccseacevesssarcesccasaccssnevsceansaeeets cosesceecucerseatensendevsetasenesaeatssssaneevaravenceaeaas 271 FETCH BURStEVM PILOt MINIMUIMN asesoran at ege 271 FETGIh BURSEEVM IEEE AVERAGB 5n icr hne rar oe rri e ar n Ceca p ere AE 272 FETOCHBURGSGEVMIIEEETMANimum tenent enn tnr terrere erinnert ense nn ene 272 FETCH BURStEVMEIEEE MINIMUM cierre A as 272 FETGh B RSEFERROGAMERG3S3Q87 itor cer hse i a rar oer e OR EE Ceca P Rer Ee rU ee 272 FETCh BURSt FERRor MAXimum GC 272 FETCHh BURSEEERROFMINIITIURI doeet rore Vere ee eege ere RA PRECOR RELY XE WERE EUN 272 FETCHh BURSt GlMBalance AVERAYER seco iaa 272 FETCh BURStGIMBalance MAXIMUM airearena ennenen nI esa 272 FETCh BURSEGIMBalance MINirm trI cc rn pp ere tp depen ner prd e tr ve o Y pd Re LG 272 FETGh B RSEIQOFISeUCAVERGaGQe irren rere eme er eee e M Fre e pore re e e ER REO cael 272 FETCh BURStIQOFPset MAXIMUM ccsccccerssscncssrsessccenscbecsessacennesncessancensanearcerscseancnedsasnesnansenteaaaesnses 272 FETCH BURSEIOOFISEE MINIMUM eege erra tret eet eee ev P Y RER AAA AR WT Nap 272 FETGI B RSELDENGIFES nce trece rere tane tercer eee yere er E prece erae Ee d 266 FETCH BURSEMGPOWermAV ERAGE orici iir a rosarinos pierre rias 273 FETCHh BURSEMGPOWOEMAXIITIUITI secrete etr e Vo rede ee AAA 273 FETCh BURSt MCPower MINimum 273 FETCH BURSHPAYLOad MAXIMUIMN csciescevessseacescencscaevszesacansaesesszesessevatncenceauedassseser
156. VT Full PPDU ei Mine2 Avg e 3 Max 94 67 us 941 704545455 ys Fig 3 21 PvT Full PPDU result display for IEEE 802 11b g DSSS standards Remote command LAY ADD WIND 2 RIGH PFPP see LAYout ADD WINDow on page 246 or CONFigure BURSt PVT SELect on page 187 CONFigure BURSt PVT IMMediate on page 187 Querying results TRACe lt n gt DATA see chapter 11 9 4 17 Power vs Time Full Burst and Rising Falling Data on page 296 PvT Rising Edge Displays the minimum average and maximum power vs time diagram for the rising edge of all PPDUs User Manual 1176 8551 02 06 40 R amp S FPS K91 Measurements and Result Displays 2 PVT Rising 1 Mine 2 Avg e 3 Mag Fig 3 22 PvT Rising Edge result display Remote command LAY ADD WIND 2 RIGH PRIS see LAYout ADD WINDow on page 246 Or CONFigure BURSt PVT SELect on page 187 CONFigure BURSt PVT IMMediate on page 187 Querying results TRACe lt n gt DATA see chapter 11 9 4 17 Power vs Time Full Burst and Rising Falling Data on page 296 PvT Falling Edge Displays the minimum average and maximum power vs time diagram for the falling edge of all PPDUs User Manual 1176 8551 02 06 41 R amp S FPS K91 Measurements and Result Displays B PVT Falling 1 Mine 2 Avg e 3 Max 168 5 us 178 5 us Fig 3 23 PvT Falling Edge result display Remote command LAY ADD WIND 2 RIGH PFAL See LAYout ADD WINDow on page 246 or
157. a elrzogd 3331 p 68 02 uonenbe zLOZ 11 Z08 PIS 3331 sJeuueoqns IO 0L OL zz uonoes ZLOZ YEW 1 Z0 981 1 Z08d 3331 Z SISLUE9QNS jolld 0L LL 0z uonoes ZLOZ 11 Z08 PIS 3331 1 o6Z1 8ZL e d LEZ EOZ 291 GEL LLL uoo peje eJ Buiuul G zz 9 qe 1 EIB 68 es GZ GZ Ce 68 LLL ZLOZ YEW L Za 22 p zo8d 3331 LL LOS ezi D vev 6EL LOL E0Z LEZ 9L 89v TLS O9L Sjueis uoo pejejoJ Buiuil g zz e qe L 1801 S4 ZLOZ YEW 120 9811 z08d 3331 LL Stz s 013 cvc 6 LL LL 6 GZ EOL 8 vez 9Gc 08 dSN asN INN Jeu gs IN 8303 pasny 1SN 9S 1esqns 19d 9s Jo os jo id 5s ejep lija BEE ON nn JO op ON JO ON JO ON ZHN prep jueuiuio2 SEN PSN 12 Ny ASN 9s 1euu1e2qns jot ZEN HEN An M99 ues 11 9 4 1 11 9 4 2 11 9 4 3 11 9 4 4 Retrieving Results JAMUNM did occideret ne pe btt e tette tate ea recae ae evade ERREUR uua 290 NP ue 290 LEE ns 290 BUSES DEE 290 e CCDF Complementary Cumulative Distribution Function 291 ee EE BEE 292 e Constellation vs Carter 293 LEM Erorys Camina sea 293 ENO vs Preamble ertt Rhen ned Radon FREE Tee Rr T M RR SS 293 EVMVS CAME M cR 293 AXEuU Erit 294 e EVM vs SYMDOL iii A AAA 294 e FFT SPD ici a linda 2
158. acy 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 CONFigtire BURSEPVTIAVERAGG c ceccceceeeeccagenenectungeateccatsedsechssanedeeeetsperenesdnanecede 231 CONFigune BURSEPVISRPONG tata tcu age eet edax oh teenie ree bread 231 CONFigure WIAN PAYLoad LENGth SRC 2 eee aree aio 231 GONFigure WLAN PVERror MRANqge iau tette teh EES ENEE 232 SENSO BURSECOUINE em 232 E Ee EEN KEE 233 SENSE E dE 233 SENSE BURSESELGCESTA TO cid aaa 233 SENSe DEMod FORMat BANalyze DBYTes EQUal esses 233 SENSe DEMod FORMat BANalyze DBYTes MAX cessisse eren nennen 234 SENSe DEMod FORMat BANalyze DBYTes MIN essen enne nnn 234 SENSe DEMod FORMat BANalyze DURation EQUal essen 234 SENSe DEMod FORMat BANalyze DURation MAX cessisse nennen 235 SENSe DEMod FORMat BANalyze DURation MIN eese enne 235 ISENGe IDEMod FORMat BANahvze GvMols EOUal eene 236 SENSe DEMod FORMat BANalyze SYMBols MAX essent 236 SENSe DEMod FORMat BANalyze S YMBols MIN eeeeeeeeeee nennen 236 CONFigure BURSt PVT AVERage Value 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
159. acy Flatness and Tolerance Parameters for AAPP A 161 How to Determine the OBW SEM ACLR or CCDF for WLAN Signals 163 Basic Measurement Examples eee 164 Measurement Example Setting up a MIMO measurement 164 Optimizing and Troubleshooting the Measurement 171 Optimizing the Measurement Results eene 171 Error Messages and Warnings eeeeeeeeeeeeeneneenenene nennen nennen 172 Remote Commands for WLAN Measurements 174 Common Sulffixoes eese SANAN ATEN ASNN AAEE RS ANANE ENA ea aka aevo aga aano ia aua aue cas 174 INTO MU CUO Mii 175 Activating WLAN Measurements esee nennen nennen nnne nnn nnns 180 Selecting a Measurement sees eene enne nnn nenne nennen nnn nennen 183 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tol TAINO ois 191 Configuring Frequency Sweep Measurements on WLAN Signals 242 Configuring the Result Display eene nennen nnn 244 Starting a Measurement eseeeeseseeeeeeeeeeee enne nennen nennen tnmen nnn nnn nnn nnne nnn 259 Retrieving Results inue eie ere aident iet m Mec e ex 264 MERI IM C 298 St
160. age 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 Manual operation See Min Max Payload Length on page 142 SENSe DEMod FORMat BANalyze DBYTes MIN lt NumDataBytes gt For IEEE 802 11b and g DSSS signals only If the SENSe DEMod FORMat BANalyze DBYTes 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 on page 142 SENSe DEMod FORMat BANalyze DURation EQUal lt State gt For IEEE 802 11b and g DSSS signals only Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance If enabled only PPDUs with a specific duration are considered for measurement analysis If disabl
161. al 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 EES Measurement settings Define units for EVM and Gain imbalance results UNIT EVM PCT UNIT GIMB PCT Programming Examples R amp S FPS K91 1 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 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 5 Performing the Measurements Run 10 blocking single measurements INITiate IMMediate WAI 222 2 2 Retrieving Results Query the I Q data from magnitude capture buffer for first ms 200 000 samples per second 200 samples TRACe1 1Q DATA MEMory 0 200 Note result will be too long to display in IECWIN but is stored in log file Query the I Q data from magnitude capture buffer for second ms TRACe1 1Q DATA MEMory 201 400 Note resu
162. alculated 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 11 3 AM AM Configuration on page 145 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 single 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 246 Or CONFigure BURSt AM AM IMMediate on page 185 Polynomial degree CONFigure BURSt AM AM POLYnomial on page 254 Results TRACe lt n gt DATA see chapter 11 9 4 1 AM AM on page 290 mum PEINE QC QNI CAMCN M NU User Manual 1176 8551 02 06 22 R amp S FPS K91 Measurements and Result Displays 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 1 AM PM Clrw 10 0 dBm Remote command LAY ADD 1 RIGH AM
163. alog box available from the WLAN 802 11 configuration Overview For further details about the CCDF measurements refer to Statistical Measurements in the R amp S FPS User Manual To restore adapted measurement parameters the following parameters are saved on exiting and are restored on re entering this measurement 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 General result analysis settings concerning the trace markers lines etc for RF mea surements 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 FPS User Manual o Analysis of frequency sweep measurements The remote commands required to perform these tasks are described in chapter 11 10 Analysis on page 298 fg JE Import Export Functions IO Data Import and Export Baseband signals mostly occur as so called complex baseband signals i e a signal representation that consists of two channels the in phase lI and the quadrature Q channel Such signals are referred to as UO signals UO
164. alysis 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 46 Auto same type as first PPDU A1st All PPDUs using a STBC field content identical to the first recognized PPDU are analyzed WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 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 222 Table info overview Depending on the selected channel bandwidth MCS index or NSS STBC the rele vant information from the modulation and coding
165. alysis is not available Remote command SENSe BURSt SELect STATe on page 233 SENSe BURSt SELect on page 233 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 10 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 233 SENSe BURSt COUNt on page 232 Source of Payload Length Defines which signal source is used to determine the payload length of a PPDU Take from Signal Field IEEE 802 11 A J P Uses the length defined by the signal field 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 231 Equal PPDU Length If enabled only PPDUs with the specified Min
166. 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 78 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 75 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 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 appl
167. ance Crest Factor of Data Carrier of Pilot Carrier Quadrature Offset Data Constellation Pilot Constellation 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 73 it can evaluate the following results e Channel Flatness based on the physical channel e Group Delay based on the physical channel e UO Offset e Quadrature Offset e Gain Imbalance 4 3 6 Signal Processing for MIMO Measurements IEEE 802 11ac n 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 73 it can evaluate the following results e Channel Flatness based on the effective channel e Group Delay based on the effective channel e EVM of pilot carriers Constellation of pilot carriers e Bitstream of pilot carriers Spatial stream results If space time encoding is implemented the demo
168. aneously 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 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 Z11 Trigger Unit and the required con nections see the R amp S FS Z11 Trigger Unit Manual 4 10 WLAN I Q Measurements in MSRA Operating Mode The R amp S FSW WLAN application can also be used to analyze UO data in MSRA oper ating mode o In MSRA operating mode the IEEE 802 11b and g DSSS standards are not suppor ted In MSRA operating mode only the MSRA Master actually captures data the MSRA applications receive an extract of the captured data for analysis referred to as the User Manual 1176 8551 02 06 87 R amp S FPS K91 Measu
169. annel The parameter is optional If you omit it the command works for the currently active channel 11 11 2 6 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 register Parameters lt BitDefinition gt Range 0 to 65535 lt ChannelName gt String containing the name of the channel The parameter is optional If you omit it the command works for the currently active channel Commands for Compatibility 11 12 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 W
170. ar file format allows you to preview the I Q data in a web browser 1 Use an archive tool e g WinZip amp 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 xml into your web browser al gt file D zy 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 FPS WLAN application The following tasks are described 8 1 How to Determine Modulation Accuracy Flatness and Tole
171. 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 BTYPe AUTO TYPE on page 226 SENSe DEMod FORMat BANalyze on page 225 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 225 5 3 9 2 Demodulation IEEE 802 11ac The following settings are available for demodulation of IEEE 802 11ac signals Demodulation Analyze PPDU Analysis Mode Auto same type as first PPDU D for each property to analyze PPDU Format to measure same type as first PPDU H Channel Bandwidth to measure Auto same type as first PPDU EI up to CBW160 MHz MCS Index to use Auto same type as first PPDU
172. are damage Remote command INPut ATTenuation on page 199 INPut ATTenuation AUTO on page 200 Using Electronic Attenuation If the optional Electronic Attenuation hardware is installed on the R amp S FPS you can also activate an electronic attenuator In Auto mode the settings are defined automatically in Manual mode you can define the mechanical and electronic attenuation separately Note Electronic attenuation is not available for stop frequencies or center frequencies in zero span gt 7 GHz 5 3 5 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 STA
173. art in measurement analysis Parameters lt Duration gt RST 1 Default unit us Manual operation See Min Max Payload Length on page 142 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance SENSe DEMod FORMat BANalyze SYMBols EQual lt State gt 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 maximum number of symbols the payload may contain see SENSe DEMod FORMat BANalyze SYMBols MAX on page 236 and SENSe DEMod FORMat BANalyze SYMBols MIN on page 236 Parameters State ON OFF RST OFF Manual operation See Equal PPDU Length on page 140 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 co
174. ary 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 143 However the results are always calculated regardless of their visibility e Number of recognized PPDUs User Manual 1176 8551 02 06 45 R amp S FPS K91 Measurements and Result Displays O ee ees e Number of analyzed PPDUs e Number of analyzed PPDUs in entire physical channel if available IEEE 802 11a g OFDM ac j n p standards Pilot bit error rate 96 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 Peak vector error PPDU EVM Quadrature offset Gain imbalance Quadrature error Center frequency error Chip cock error Rise time Fall time Mean power Peak power 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 12 Remote command LAY ADD 1 RIGH RSG see LAYout ADD WINDow on page 246 Querying results FETCh BURSt ALL on page 269 Signal Field This result display shows the 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 carri
175. ased 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 196 Frequency Offset Shifts the displayed frequency range along the x axis by the defined offset This parameter has no effect on the instrument s hardware or on the captured data or on data processing It is simply a manipulation of the final results in which absolute fre quency values are displayed Thus the x axis of a spectrum display is shifted by a constant offset if it shows absolute frequencies but not if it shows frequencies relative to the signal s center frequency A frequency offset can be used to correct the display of a signal that is slightly distorted by the measurement setup for example The allowed values range from 100 GHz to 100 GHz The default setting is O Hz Note In MSRA mode this function is only available for the MSRA Master Remote command SENSe FREQuency OFFSet on page 197 5 3 4 4 Amplitude Settings Amplitude settings determine how the R amp S FPS must pro
176. ate IEEE 802 11b and g DSSS 186 CONFigure BURSt EVM ECHip IMMediate ccocooccccococcccnonoconanonananancncnancn nana nononanenene 186 CONFigure BURSt EVM ESYMbol IMMediate esee nennen 186 CONFloure BURGCGAIN GC Arer IMMedlatel nana nanannnnnn 186 CONFigure BURSt PREamble IMMediate esses nennen 187 GONFigure BURSEPREamble SELeel 2 1 rir ie 187 CONFloure BURGCb Rackingat MMedatel nnnm 187 CONFigure BURSEPVT INMediate tora eraat eat o rtt ette reet ct 187 CONFigure BURSEPVT SEL6GGl uicti e recen eere ia 187 CONFigure BURSt QUAD QCARrier IMMediate eese 188 CONFigure BURSESPECHUMIFF T IMMediate 2212 dana 188 CONFIigure BURSESPECtrum FLEATness SELect ciere NEEN EVERE EEN 188 CONFigure BURSt SPECtrum FLATness IMMediate cesses 189 Selecting a Measurement CONFloure BURG GTATleticeBGTbReamt MMediatel rn rnrnnnnnnnne 189 CONFloure BURG GTATletice GEledt MMediatel ns esesnrnn es enenererernrenenerenes 189 DISPlay MWINDOwWsn gt iS E srein aaiae raean iaraa ai aadi 189 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 lt n gt IMMediate command Usage Event Manual operation See AM AM on page 22 CONFigure BURSt AM
177. ate lt n gt MARKer lt m gt STATe 8 CALGCu latesn gt ET e UE GAL GCulatesns MSRA CALINeEMAlLUe iacu eee petite ease alin da e ee too 241 CALCulate n MSRA WINDowcxn IVAL sse enne nnne hn nen niet rennen nr cnnnnn rc sen rnn sns nnns 241 CAL GCulatesn STATistics RESUlkeE 7 rete ctrca cre tii 282 GAL Culatesns UNIT PONWGE ince tei ceci oe EE Pre cr rece dt at ira 198 CONFigure B RSCAM AM POLYnotmlal tnra tron eant nicae rp eene ETE EARNE 254 CONFigure BURStAM AM IMMediate GONFigure BURSCEAM EVME IMMAediate 21 rent eere re nre rca th en eror rea CONFigure BURSEAM PMEIMMIedliate tci cien rop ineo tener EE ETE ATAA XXX Ig Fe oye pce ag CONFigure BURSECONSt CCART ier IMMediate netten trt rennen CONFigure BURSt CONSt CSYMbol MMediate CONFigure BURSEtEVM ECARrier IMMediate 1 en nter trennt penne pner CONFigure BURSEEVM ECHip IMMedli te reet nte ert tt rn nere erts GONFigure BURSEtEVM ESYMbol IMMediate ntt nda CONFigure BURSt EVM ESYMbol IMMediate IEEE 802 11b and g DSSS sss 186 CONFigure BURSEGAIN GCARrier IMMediate 2 rrr n rn rt rr rere 186 GONFigQure BURSEPREamble SELGCE ies erro erre tai Ree or ey a E at HU ETUR RN T ruere CONFigure BURSt PREamble IMMediate E GONFigure BURStPTRacking IMMediate 59 ott rt eee ertt ern tio e
178. ated regardless of their visibility Tx channel Tx All UO offset dB Gain imbalance dB Quadrature offset UO skew ps PPDU power dBm Crest factor dB Receive channel Rx All PPDU power dBm Crest factor dB MIMO cross power Center frequency error Symbol clock error CPE Bitstream Stream All e Pilot bit error rate 96 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 12 Remote command LAY ADD 1 RIGH RSD see LAYout ADD WINDow on page 246 Querying results FETCh BURSt ALL on page 269 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 R amp S FPS K91 Measurements and Result Displays Limit 1 Result Summary Global No of PPDUs Recognized 3 Analyzed 3 Analyzed Physical Channel 0 PPDUs Min Limit Unit Peak Vector Error 1 18 35 00 35 00 Quadrature Error enter Freq Error Chip Clock Error Fall Time Mean Power Peak Power Fig 3 26 Global result summ
179. ation on page 117 CONFigure WLAN RSYNc JOINed lt State gt This command configures how PPDU synchronization and tracking 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 115 11 5 5 Synchronization and OFDM Demodulation SENSe IDEMOGEE T OFESGl 11e pues ari erp ede e pete ndn epp eati e pre ryan e epa tuti ee Ar 213 ill 214 SENSe DEMod FFT OFFSet Mode This command specifies the start offset of the FFT for OFDM demodulation not for the FFT Spectrum display Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Mode gt AUTO GlCenter PEAK AUTO The FFT start offset is automatically chosen to minimize the intersymbol interference GlICenter 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 120 SENSe DEMod TXARea State If enabled the R amp S FPS 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 o
180. atus Registers iue Sick Sap ens dec isi desea i riii naa daa dest daa ie 301 Commands for Compatibility eese nnn nnn 306 Programming Examples R amp S FPS K91 eeeennnneenn 308 Annex E 313 Sample Rate and Maximum Usable UO Bandwidth for RF Input 313 VO Data File Format iq tar ooooonnnncconononaccnnncnnncnnnnncnnancrnnnrnnnnnn cnn nnnm 316 List of Remote Commands WLAN eene 323 m e 330 User Manual 1176 8551 02 06 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 FPS User Manual The main focus in this manual is on the measurement results and the tasks required to obtain them The following topics are included chapter 2 Welcome to the WLAN Application on page 8 Introduction to and getting familiar with the application chapter 3 Measurements and Result Displays on page 12 Details on supported measurements and their result types chapter 4 Measurement Basics on page 57 Background information on basic terms and principles in the context of the mea surement chapter 5 Configuration on page 89 and chapter 6 Analysis on page 156 A concise description of all functions and
181. base unit the window suffix lt n gt is not considered in the R amp S FPS WLAN application Use the DISPlay WINDow lt n gt SELect to select the window before you query trace results For details see chapter 11 9 4 Measurement Results for TRACe lt n gt DATA TRACE lt n gt on page 287 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 Emission 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 AM AM on page 22 See AM PM on page 23 See AM EVM on page 23 See Bitstream on page 24 See Constellation on page 26 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 33 See Gain Imbalance vs Carrier on page 33 See Group Delay on page 34 See Magnitude Capture on page 35 See Phase Error vs Preamble on page 37 See Phase Tracking on page 37 See PLCP Header IEEE 802 11b g DSSS
182. bbreviations timing offset NT frequency offset phase offset estimate of the gain factor in the I branch estimate of the gain factor in the Q branch accurate estimate of the crosstalk factor of the Q branch in the I branch estimated baseband filter of the transmit antenna estimated baseband filter of the receive antenna estimate of the IQ offset in the I branch estimate of the IQ offset in the I branch measurement signal 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 IMACY 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 65 e Calculation of Signal Parameters t rn a Reed eer Ero eb adea rea nite 67 e Literature on the IEEE 802 11b Standard 70 Block Diagram for Single Carrier Measurements A block diagram of the measurement application is shown below in figure 4 2 The baseband signal of an IEEE 802 11b or g DSSS wireless LAN system transmit antenna
183. cated in the diagram 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 Green colored arrows represent auxiliary connections of SMA plugs of the R amp S OSP B101 option 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 SGOSP130 switch platform the IP address is shown in the front dis play When using a R amp S OSP120 switch platform connect an external monitor to get the IP address or use the default IP address of the OSP switch 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 User Manual 1176 8551 02 06 116 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 212 OSP Switch Bank Configuration Sequential
184. ccccnonccnonninnnnns 255 DISPlay WINDow N TRACe t Y SCALe AUTO HYSTeresis UPPer LOWer eese 256 DISPlay WINDow N TRACe t Y SCALe AUTO HYSTeresis UPPer UPPer sees 256 DISPlay WINDow n TRACe t Y SCALe AUTO MEMory DEPTh essen 257 DISPlay WINDow n TRACe t Y SCALe AUTO MODE essere nennen 257 DISPlay WINDow n TRACe t Y SCALe DlVisions esee 258 DISPlay WINDow n TRACe st Y SCALe MAXimum eese ennemis 258 DISPlay WINDow n TRACe t Y SCALe MlINimum esee nennen 259 DISPlay WINDow n TRACe t Y SCALe PDlVision essent nennen 259 DISPlay WINDow n TRACe st Y SCALe RLEVel eese enne rennes 199 DISPlay WINDow n TRACe t Y SCALe RLEVel OFFSet sees 199 DISPlay WINDow lt n gt ZOOM AREA DISPlay WINDow lt n gt ZOOM MULTiple lt zoom gt AREA DlSblavWINDow nzt ZOOMMUL Tple zoomGTATe enne nnne 301 DISPlayEWINDowsn E ZOOM STATE corsa vict rrt eee Petr tienne ti ain 300 FETCHh BURSEALL EN 269 FETCI B RSCAM AM GOEFfICI nIS cnr teet to nectit n ct etr een ene E n tra d e NEEN 270 EFETGIEB RSEBERPIIGEAVERGUGS E 270 FETCh BURSt BERPilot MAXimum FETCh BURSEBERPIOEMINIMUME ott ri td te
185. cess 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 m 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 cote eere e Ra 102 L Reference Level Mode nano 102 L Reference Level 103 Us flc MEET NEM 103 L Shifting the Display O feet naanin 103 e he na nese ed ced nee incall glenda tls 103 L Setting the Reference Level Automatically Auto Level 104 REASON E 104 L Attenuation Mode Value nono rncnononcnnos 104 Using Electronic Atfenualtloh coiere etin re vee 104 PN WE SULA ce 105 L Preamplifier option B33IB34A nooo 105 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 de
186. 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 l Lk sk j phase phase ro K mwa X4 Xg X A x Lk N FFT 4 1 with Knog the modulation dependant normalization factor User Manual 1176 8551 02 06 59 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM j p e aj the symbol of sub carrier k at symbol eg the gain at the symbol in relation to the reference gain g 1 at the long symbol LS e Hy 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 phase mino the phase of sub carrier k at symbol caused by the timing drift see Common phase drift e nj the independent Gaussian distributed noise samples Phase drift and frequency deviation The common phase drift in FFT is given by phase 29x N INxMAf rest Txl dy Common phase drift 4 2 with e
187. css hara pe ra KANNER tandil 271 FETCI BURSEEVMEIDIRSGEMINIM eebe AEN 271 FETCHBURSECEVMEP Lot AVERSge ou 271 FETGCh BURSEEVM PIEGEMAXIUE 251 redacto donacion cdi 271 FETCh BURStEVM PILot MiNimum eene nnnm enne nennen nnn 271 FETCh BURSEEVML IEEE AVERGOS9g i etcetera a is 272 FETCh BURSEEVMEIEEE MJAXIRISITIT 222222 toe ia anoo Co po sre e dE EEN 272 FETCh BURSCEEVMEIEEE MINIPYUER T uiii pee aii 272 FETCI BURSEOCPERIOEAVERaAdgG EE 272 FETCh BURSECFERrOIEMADXIUM icio reote pec d Eri eno e e io io esee Eid t E aie 272 Retrieving Results FETOIBURSEGFERrIOEMINITIDD 5 tic died decebiauesahevlssncdieeinabaedacesvas iA EAE ENEA N aAA 272 FETCH E 2 iiec ota ue E Hub k e EEA EARTE ERENER 272 FETGHBURSEFERROEMAXIITIIITIS icc 7 ore Lore tantes rper yao ici ariadna dais 272 FETCHBURSEFERRO MINIMUM KEE 272 FETCH BURStGIMBalance AVERAage cisco 272 FETOCh BUbRGrGlMBalance MANimum ini neninanadaa hanni ian nnna a ania k nanara iana 272 FETCh BUbRGrGlMBalance MlNimum 272 FETCH BURStIQOFisetAVERage coincida 272 FETCH BURStEIQOF SCt MAXiMum cocaiccnonanoci an concisa adan dd cad ee EENG 272 FETCHBURSEOOPISCEMINIMUMA rice o i nica nanaedcdessaeadecesdniesedebesaauasccssandadedesense 272 FETCh BURSEGEVMEALL AVERAUG rtu A A xad ENEE 273 FETCHh BURSEEVMEPALEEIMAXIRIUITUS ua eren ed atat qe Gea aereo oca Ya vvv ead e yaQ ue Fas a aad NEEN CA 273 FETGILBURSEEVMEALE MINIBOMITI EE
188. ctory displayed in the file selection dialog box depends on the standard you selected in step step 2 5 f necessary adapt the settings as described for the individual measurements in the R amp S FPS User Manual 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 Exitthe 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 In the 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 Measurement Example Setting up a MIMO measurement 9 Basic Measurement Examples This section provides step by step instructions for working through an ordinary mea surement In this example a DUT using IEEE 802 11a is used T
189. d display Abbreviation in Signal Parameter in Demodulation settings Field display Aist Auto same type as first PPDU Al Auto individual for each PPDU WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Abbreviation in Signal Parameter in Demodulation settings Field display 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 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 11 9 4 18 Signal Field on page 297 Remote command LAY ADD 1 RIGH SFI see LAYout ADD WINDow on page 246 or CONFigure BURSt STATistics SFIeld IMMediate on page 189 Querying results TRACe lt n gt DATA see
190. d all with specified MCS D The MCS Index setting is used for all PPDUs Remote command SENSe DEMod FORMat MCSindex MODE on page 228 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 228 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 46 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 AI All PPDUs are analyzed Meas only the specified Nsts M Only PPDUs with the Nsts specified for the Nsts on page 129 set ting are analyzed Demod all with specified Nsts D The Nsts on page 129 setting is used for all PPDUs Remote command SENSe DEMod FORMat NSTSindex MODE on page 229 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 229 STBC Field Defines the PPDUs taking part in the an
191. d 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 4 2 3 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 4 3 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 FPS can measure multiple data 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
192. d 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 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 values 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 BPSK 6 Mbps amp 9 Mbps Non HT 5 MHz 10 MHz 20 MHz g OFDM jP QPSK 12 Mbps A Short PPDU 18 Mbps Long PPDU 16QAM 24 Mbps amp 36 Mbps 64QAM 48 Mbps amp 54 Mbps IEEE 802 11ac 16QAM VHT 20 MHz 40 MHz 80 MHz 64QAM 160 MHz 256QAM 1024QAM IEEE 802 11b DBPSK 1 Mbps Short PPDU 22 MHz g DSSS DQPSK 2 Mbps Long PPDU CCK 5 5 Mbps amp 11 Mbps PBCC 5 5 Mbps amp 11 Mbps requires R amp S FPS bandwidth extension option see chapter A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input on page 313 4 7 4 7 1 4 7 2
193. data follows the syntactic rules of keywords You can enter text using a short or a long form For more information see chapter 11 2 2 Long and Short Form on page 176 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 quotation 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 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 WL
194. de EE 87 RF meas uremietits trenes 51 MSRA applications Capture EE Capture offset remote MSRA Master Data Coverage erede rne E Era 88 Multiple Measurement channels AA 89 N Ness PPDUS uv tai 135 218 Nof symbols n ata n 59 Noise Additive white Gaussian AWG SOURCE orici nee ed Normalizing Power MIMO socia cip 137 Nsts EES det 129 229 Number of samples Displayed cocinar 10 O OBW Configuring applications Result ree node e agro Occupied bandwidth SEENEN 53 Offset Ampliticationm RI WE 16 18 Analysis interval 106 112 Calles eiiis ei io n eo Ne sie ocio 16 gize me Q 101 Phase angle I Q 17 18 elt Lee oreet eerta 17 18 Reference level siisii iaaii aea 103 Options Bandwidth extension oooccccinoccccnoccccnoncccnonancninnn cocinan 313 Electronic attenuation 104 Preamplifier B24 cuand 105 OSP switch box Antenna connection MIMO nsec 117 IP addr ss via odd e Coe trees 116 Setup Jus State MIMO ET 116 Output Configuration euet rer err tete aei etes 98 Configuration remote 4 195 Noise source 81 98 Paramotor titi o Recette 81 Sample rate definition 25 919 Gu 98 Ee 99 112 Overview Configuring WLAN measurements 93 P Packet search IEEE 802 11a g OFDM lp 59 Parameters Frontend eru M 82 Inp tsighalls i ertt eire dt ka
195. 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 Q on page 107 SENSe SWEep TIME lt Time gt This command defines the sweep or data capture time Parameters lt Time gt refer to data sheet RST depends on current settings determined automati cally 11 5 4 2 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Example SWE TIME 10s Usage SCPI confirmed Manual operation See Capture Time on page 106 TRACe IQ SRATe lt SampleRate gt This command sets the final user sample rate for the acquired l Q data Thus the user sample rate can be modified without affecting the actual data capturing settings on the R amp S FPS 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 313 Range 100 Hz to 10 GHz continuously adjustable RST 32 MHz Manual operation See Input Sample Rate on page 106 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 107 The OPC command should be used af
196. ds are required to query the status of the R amp S FPS and the WLAN application For details on the common R amp S FPS status registers refer to the description of remote control basics in the R amp S FPS User Manual e General Status Register Commands esee trennen 303 e Reading Out the EVENt Part cierre neret netten ttn in Eee dead 304 e Reading Out the COINDIUDOD Paba 304 e Controlling the ENABIS Pat ie re ia 304 e Controlling the Negative Transition Part 305 e Controlling the Positive Transition Part eet tte 305 General Status Register Commands STATUS PRESO M m 303 STATus QUEwue NEXT icio trae ad ec teh aeneo a eee 303 STATus PRESet 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 O to 1 are detected All NTRansition parts are set to 0 i e a transition from 1 to 0 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
197. dulated data must first be decoded to determine the following results e EVM of data carriers Constellation diagram e Bitstream The 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 72 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 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
198. e NEW on page 180 For a list of available channel types see INSTrument LIST on page 181 Parameters lt ChannelType gt Channel type of the new channel For a list of available channel types see table 11 3 WLAN WLAN option R amp S FPS K91 lt ChannelName gt String containing the name of the channel Example 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 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 94 11 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 11 8 Starting a Measurement on page 259 Selecting a Measurement For details on available measurements see chapter 3 Measurements and Result Dis plays on page 12 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
199. e an offset from the start of the captured data to the start of the application data for the WLAN UO measurement The analysis interval used by the individual result displays cannot be edited but is determined automatically However you can query the currently used analysis interval for a specific window The analysis line is displayed by default but can be hidden or re positioned Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Remote commands exclusive to MSRA applications The following commands are only available for MSRA application channels CALC latesn EE ee EE 241 CALCulate lt n gt MSRA ALINEe VALUE cccccceceeeeeeeeeee iiidid enne nnns niaaa 241 CALCulate lt n gt MSRA WINDow lt p gt MAL 241 Nimate Sti EE 242 SENSE MSRASCAP Ture OFF EE 242 CALCulate lt n gt MSRA ALINe SHOW This command defines whether or not the analysis line is displayed in all time based windows in all MSRA applications and the MSRA Master lt n gt is irrelevant Note even if the analysis line display is off the indication whether or not the currently defined line position lies within the analysis interval of the active application remains in the window title bars Parameters lt State gt ON OFF RST ON CALCulate lt n gt MSRA ALINe VALue lt Position gt This command defines the position of the analysis line for all time based windows in all MSRA applications and the MSRA Master
200. e 44 However the results are always calculated regardless of their visibility on the screen 5 3 11 2 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance IEEE 802 1 tj 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 OI Fig 5 8 Result Summary Global configuration for IEEE 802 11a ac g OFDM j n p standards Remote command DISPlay WINDow lt n gt TABLe ITEM on page 252 Spectrum Flatness and Group Delay Configuration For MIMO measurements Spectrum Flatness 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 73 R amp S9FPS K91 Configuration WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Spectrum Flatness TIA Effective Channel B Saad 3 Spectrum Flatness Remote command CONFigure B
201. e Config Auto Level Capture Offset Center e eenereetes Continue Single Sweep s is sisi 150 Continuous SEQUENCER sirsenis 90 Continuous Sweep ve Display Config MET EXPO Mb c External Free Run en Frequency Config UO Power linport oes D Input SOURCE Conflg irre tei tnt 96 IQ EXPOSE Licini me eee tete eee reg 158 IQ Import 158 OUTPUTS CONT eeneg 98 Preamp wei 105 R f Level Offset ome retener 103 hcic e 151 Resultats 143 RE Atten AUTO EE 104 RF Atten Manual cinco 104 RE Power siisii 109 Sequencer 90 Signal Capture 105 Signal Description i95 Single Sequence A reiri ipamana 90 Single SWEEP WEE 150 Sweep Config Trigger Config Trigger Offset Space Time Block Coding See STBG til enda 129 135 SPACETIME STEAM E 73 Span Me EE ES 91 Spatial mapping mode MIMO ttn tenente e Ct d 137 User defined MIMO eee 138 Specifics for Configuration n en terret ra eines 94 Spectrum Emission Mask 86 SEM ET 52 Spectrum Flatness Parameters 2 tec e d est 12 Result display Trace data iH eue iHe ter Coo des Standard see Digital standard nete 10 Standard WLAN measurements seses 12 Starting WLAN application trente 9 UE ee LEE 140 141 233 REMOTE MR 232 Statistics PPD C
202. e 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 11 2 6 1 Introduction Parameters may have different forms of values WC unten ore rae t ric aed cie ea eei ae e b e a d o Dad 178 s BOON i EE 179 e Character DES EEN 179 Character SUIS iiec teer ceder e centered eae breed bte dd ee 179 e JBISCIP E EE 179 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
203. e are considered Remote command IEEE 802 112 g OFDM SENSe DEMod FORMat BANalyze SYMBols EQUal on page 236 IEEE 802 11 b g DSSS SENSe DEMod FORMat BANalyze DURation EQUal on page 234 SENSe DEMod FORMat BANalyze DBYTes EQUal on page 233 Min Max Payload Length 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 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 131 Remote command SENSe DEMod FORMat BANalyze SENSe DEMod FORMat BANalyze SENSe DEMod FORMat BANalyze SENSe DEMod FORMat BANalyze BYTes MIN on page 234 URation MIN on page 235 BYTes MAX on page 234 URation MAX on page 235 OD OO PVT Average Length 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 39 Remote command CONFigure BURSt PVT AVERage on page 231 PVT Reference Power Sets the reference for the rise and fall time in PVT calculation to the maximum or mean PPDU power For detail
204. e erae ees reve rte bh e reci e e Yerba EYE EFE ERA 303 oxSTem PRESeECHANtel EXEGUte iitt neenon xs leads irc anne 183 EK ECNR RS ee 264 TRAGeGTQ DATAMEMORya inciter here da Rr Y ru EFE REIHE PER E YN 286 TRACE IQ SRAT c cenceveene 203 TRAGOS DATA e 284 Ree EE E RE 286 TRiIGger SEQuence VEV 6l POWErAUT a DEE 206 TRIGger SEQuerce D TIMG nere taper onte tret e rer tp rne et rre ee ener vcr nas TRIGger SEQuence HOLDOoft TIME 2t tnter rtr trn re err rr rennen TRIGger SEQuence IFPower HOLDoff TRIGger SEQuerice IFPower HYSTeresis nott tren en rne prr n tene re 204 TRIGger SEQuence LEVel IEPOWSLE 2 ttr ir rtt trien rr Rr erret re p rer n PR Ee YER eh 205 TRIGE SEQuence HEV SLI QPOWES E 205 TRIGger SEQuerice E LEVEL REPOWF oirtt t retra ed 206 TRIGger SEQuence LEVel EXTerrnal port 5 2 1 tn t rettet perro rne trennt 205 TRIGGER SEQUENCE MODE e TRIGger SEQuence SLOPe TRIGger SEQuence SOURCe prre id rere oc ra O eni XE SE EXER ERE RE og UNI SRS e UNIT EVM e S UNIT GIMBalance ET UNIT GT ui EECH Index A Abbreviations Signal processing IEEE 802 11a g OFDM j p 57 Aborting Sweep AC DC coupling ACLR Configuring cdma2000
205. e 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 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 FPS 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 Command usage 11 2 2 11 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 s
206. e limit value is defined by the standard or the user see CALCulate LIMit BURSt EVM ALL MAXimum on page 238 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 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 238 Retrieving Results 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 PILot AVERage RESult CALCulate LIMit BURSt EVM PILot 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 238 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 lim
207. e output is sent 2 TRG AUX Parameters lt Length gt Pulse length in seconds Manual operation See Pulse Length on page 100 11 5 4 3 MIMO Capture Settings The following commands are only available for IEEE 802 11ac n standards Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Useful commands for defining MIMO capture settings described elsewhere CALCulate lt n gt BURSt IMMediate on page 261 Remote commands exclusive to defining MIMO capture settings CONFloure WAN ANTMatrtv ADDtess add eee eeeeeseceeeeeeeeeeeeeeeeeeeeees 210 CONFloure WAN ANTMatrtv ANTenna Analyzerz tn rnnnnrnnnnennt 210 CONFloure WAN ANTMatrtv GOUlbce ROSCHlator GOUlbce 210 CONFigure WLAN ANTMatrix STATe state essere 211 GCONFigureWLAN DU TGobhfig 221 Ine ceased eite ede taco A rici ee voee evo eae s 211 CONFloure WAN MIMO CAbTure rhe ennen enn sn ennt nnns s ntn tr tr tierna rina 211 CONFloure WAN MiMO CAbTure BUFFE eene nennen eren 212 CONFigure WLAN MIMO CAPTUre TYBPE 2 aiiiar eoi a e vaa 212 GONFigure WLAN MIMO OSP ADDR GSS neun retur toten et tt ne e yan rata 212 CONFigure WLAN MIMO OSP MODul8 sete nen ennt nnns tnr tnt nn nha na n 213 CONFPigure WLAN RSYNC JONGO rison aa enr ad eh x e etu eene entre 213 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
208. e rrt e n rer ra ver ra EE HERE 246 LAY OuURGCATalogE WINDOW m 248 heideger Tele RE 248 EAYout REMove WINBOW 5t rien rer rtr htt nera he ei rera e Ra E ER ad LAYout REPLace WINDow es LAYOUESPRIMG T LAY out WINDOW N gt ADDI coria rre rer sere rer Rr deed ER e e E c dr FE Y EE ETE REM 251 EAYGUuEWINDOW lt N gt IDEN Y thiccia 251 LAYOUEWINDOW N gt REMOYV Grassot ngeneni AAA 252 LAYOUCWINDOWS N gt EE 252 MMEMON LOAD IQ STAT E reirte TE ie PH MMEMory LOAD SEM STATe m MMEMory STOResn IQ STATO iiti eren tra eoe tai 298 OUTPuUrMRIGGErSPOM DIRGCUON p 208 OUTPut TRIGgersport lEVel s ctr rtr Re err e tp rn Gre eap eee e AAA 208 OUTPut TRIGgersport OTYPO irte rcr intret i o eere eret resa errat rere aan 209 OUTPURTRIGgersport gt EE E TEE 209 OUTPut TRIGgersport PULSe EENGILh noatro rere nennen rin er nre re T vanes 209 STATUS OPERation CONDON snc c cereo diate ni AA cete rcr ee DE ERES 304 STATUS OPERalion ENABIe ere tre oae rer tea nro Fev RUNE ES AE Ea S ER EErEE ETE Eur FREE E CERE Eo seed 304 STATus OPERatiori NTRanSIUOR sco ho cpu ELENG 305 STATUS OP E er HGH aere oon eere Coram dese EES 305 STATUS OPERaltiorniBEVENI J eerte nre tre nm tad in err e e eoi cde 304 STATUS PRES Olivari dieta
209. eak power gt lt min rms power gt lt avg rms power gt lt max rms power gt lt min crest factor gt lt avg crest factor gt lt max crest factor gt min freq error gt lt avg freq error max freq error gt min symbol error avg symbol error max symbol error min IQ offset avg IQ offset max IQ offset min gain imb avg gain imb max gain imb gt min quad offset avg quad offset max quad offset min EVM all avg EVM all max EVM all min EVM data avg EVM data gt max EVM data min EVM pilots avg EVM pilots gt max EVM pilots min BER avg BER max BER min IQ skew gt avg IQ skew gt max IQ skew gt min MIMO CP avg MIMO CP max MIMO CP min CPE avg CPE gt max CPE gt Manual operation See Result Summary Detailed on page 43 See Result Summary Global on page 44 Retrieving Results FETCh BURSt AM AM COEFficients This remote control returns the coefficients of the polynomial regression model used to determine the AM AM result display See AM AM on page 22 for details 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 FETC BURS AM AM COEF Usage Query only FETCh BURSt BERPilot AVERage FETCh BURSt BERPilot MAXimum FETCh BURSt BERPilo
210. eck has passed FAIL Limit check has failed Example INIT IMM WAI CALC LIM ACP ACH RES PASSED PASSED Usage Query only CALCulate lt n gt LIMit lt k gt FAIL This command queries the result of a limit check For measurements in the R amp S FPS WLAN application the numeric suffix lt k gt specifies the limit line according to table 11 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 result This is only possible for single measurement mode See also INITiate lt n gt CONTinuous on page 261 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 52 Table 11 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 Retrieving Results 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 lt n gt MARKer lt m gt FUNCtion POWer lt sb gt
211. ect 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 lla II Enea Prior IEEE 802 11 2012 Standard Ee EE 95 o C 95 Tolerance WDR ecco beri Det des ee cer ea coetu es catu eue cedo 95 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 80 Note In MSRA operating mode the IEEE 802 11b and g DSSS standards are not supported Remote command CONFigure STANdard on page 191 Frequency Specifies the center frequency of the signal to be measured Remote command SENSe FREQuency CENTer on page 195 Tolerance Limit Defines the tolerance limit to be used for the measurement The required tolerance limit depends on the used standard Prior IEEE 802 11
212. ed Manual operation See Attenuation Mode Value on page 104 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 FPS determines the signal level for optimal internal data processing and sets the required attenuation accordingly 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 104 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 200 If the current reference level is not compatible with an attenuation that has been set manually the command also adjusts the reference level This command requires the electronic attenuation hardware option Parameters lt 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 Using Electronic Attenuation on page 104 INPut EATT AUTO lt State gt This command turns automatic selection of the electronic attenuation on and off If on electronic attenuation reduces the mechanical attenuation whenever possible This command requires the electronic attenuation hardware option Parameters lt S
213. ed 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 State 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 measurement analysis 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 on page 142 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 p
214. ed by selecting the high lighted softkey or key again Remote command INITiate lt n gt IMMediate on page 261 Continue Single Sweep After triggering repeats the number of sweeps set in Sweep Count without deleting the trace of the last measurement 5 4 Frequency Sweep Measurements While the measurement is running the Continue Single Sweep softkey and the RUN SINGLE key are highlighted The running measurement can be aborted by selecting the highlighted softkey or key again Refresh This function is only available if the Sequencer is deactivated and only for MSRA applications The data in the capture buffer is re evaluated by the currently active application only The results for any other applications remain unchanged This is useful for example after evaluation changes have been made or if a new sweep was performed from another application in this case only that application is updated automatically after data acquisition Note To update all active applications at once use the Refresh all function in the Sequencer menu Remote command INITiate lt n gt REFResh on page 242 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 12 However some parameters specified in the WLAN 802 11 standard require a better signal
215. ed during the WLAN IQ measurement Signal Capture Trigger Source Trigger In Out Input Sample Rate Capture Time Swap IQ Filter Filter out Adjacent Channels Tutelle ET 106 Capture MMC ccc uc teas A 106 e nV Sunc NE E 106 Swap VO E EE 107 Suppressing Filter out Adjacent Channels IEEE 802 11a g OFDM ac j n p 107 Input Sample Rate This is the sample rate the R amp S FPS WLAN application expects the l Q input data to have If necessary the R amp S FPS has to resample the data During data processing in the R amp S FPS the sample rate usually changes decreases The RF input is captured by the R amp S FPS using a high sample rate and is resampled before it is processed by the R amp S FPS WLAN application Remote command TRACe IQ SRATe on page 203 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 202 Capture Offset This setting is only available for applications in MSRA operating mode It has a similar effect as the trigger offset in other measurements it defines the time offset between the capture buffer start and the start of the extracted application data WLAN IQ Measurement Modulation Accuracy Flatness Tolerance In MSRA mode the offset must be a positive value as the capture buffer starts at the trigger time 0
216. ed 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 223 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 46 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 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 228 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
217. edoe ix 12 Data carriers limit check result remote 276 eet RE 20 IEEE 802 11b g DSSS 520 Limit check result remote ssssssss 276 Limits remote coc ettet need 238 Optimizing 121 215 leger v c coser ctii te eroe cade 12 Pilot carriers limit check result remote 277 TRIER EE 19 Units vs carrier result display VS cartier trace dala eerte eterna vs chip result display vs symbol result display Exporting AAA ara 1 Q data remote Ec M Extension Spatial Streams PPBUS erre te etie eet Cua External trigger Level remote F FFT AWGN channel IEEE 802 118 g OFDM j p 59 e ridad 79 Signal processing IEEE 802 11a g OFDM j p 59 Spectrum result display sessss 31 Spectrum trace data sis Start offset suse e Start offset remote AA Files Format NVO KE ME 316 I O data binary XML scere 320 UO parameter XML sse 317 Filters Adjacent channels YIG remote imde eco oeil Format Data remote snan eitis 283 EDU rermote second 226 Free Run WWI QQ uc coc pini mc ea ne bt eines 109 Freq Error vs Preamble IResultdisplays initio etii Seton pn ci a s 33 Frequency L elle ULT E 100 Configuration remote s 195 DG VIAUOM a A a 60 Error limit remote
218. ee Peak Vector Error Meas Range on page 142 SENSe BURSt COUNt Value If the statistic count is enabled see SENSe BURSt COUNt STATe on page 233 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 Value 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 BURSt SELect Value If single PPDU analysis is enabled see SENSe BURSt SELect STATe on page 233 the WLAN I Q results are based on the specified PPDU If disabled all detected PPDUS in the current capture buffer are evaluated Parameters Value RS
219. eep measurements eina s2 c T nese 51 Spectrum Emission Mask reb dl e e er ee e Ce a EE RR 52 Occupied Ranger niet itd ee anne SES Een 53 rr EP 54 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 User Manual 1176 8551 02 06 51 R amp S FPS K91 Measurements and Result Displays JEE The R amp S FPS 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 17 dB SWT 100 ms s VBW 300 kHz Mode Auto Sweep 1Rm Clrw CF 850 0 MHz 1001 pts 419 0 kHz Span 4 19 MHz 2 Result Summary CDMA 2000 Channel Bandwidth Offset Power T Ref 229 MHz 0 86 dBm Tot 7 0 8 Channel Upper 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 152 Remote command CONFigure BURSt SPECtrum ACPR IMMediate on page 190 Querying results CALC MARK FUNC POW RES ACP see CALCulate lt n gt MARKer lt m gt FUNCtion POWer lt sb gt RESu1t on page 280 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
220. eesese 293 Constellation vs symbol sees 292 Data format remote te tier 283 Evaluating rre rnt ente 156 EVM VS Carnet attore eere ren eoe Rte dh 293 EFT SpOCUUTI isa ceu epp tiet dn 295 AA irae 295 Magnitude Capture 5 enters 287 Numeric remote e ACEN 265 PvT Full Burst 296 Result summary 287 Retrieving remote 264 RE OMOTE coit eth even oce eere pe 278 Signal field de 297 Spectrum Flatness 22297 Trace remote 283 Trace data query remote SH Updating the display 2191 Updating the display remote ssssse 242 Retrieving Numeric results remote A 265 Results remote ote RF Re s lts remote eene pene 278 Trace results remote esee 283 RF attenuation Ue 104 Manual 104 s alil pe 96 E ue 193 194 RF measurements POLI 156 Configuration remote n 242 MSRA T 51 Results remote 2 278 Step by step 1 2 rne err rp ite rri 163 RF Power Re 109 Trigger level remote sees 206 RUN CONT WA E M 150 RUN SINGLE KEY M 150 S Sample Tato tual sis 12 14 Definition zs Displayed Mt MAXIM sucias oa Relationship to bandwidth in REMOTE ainia Samples INTR ita 12 14 Scaling
221. el Fig 4 7 Effects of the trigger hysteresis See Hysteresis on page 111 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 wr Y Drop Out Fig 4 8 Effect of the trigger drop out time See Drop Out Time on page 110 D Drop out times for falling edge triggers If a trigger is set to a falling edge Slope Falling see Slope on page 111 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 occur 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
222. emark of Rohde amp Schwarz GmbH amp Co KG Trade names are trademarks of the owners The following abbreviations are used throughout this manual R amp S9FPS is abbreviated as R amp S FPS R amp S FPS K91 Contents D ooo c 5 141 Aboutthis Manual enero erret nie npa DURER ERR ERR RR NR ARRA RE RES 5 1 2 Documentation Overview iniret tenant rune ERR ce te RE EE ERR X RE Ryu a RE iia raras 6 1 3 Typographical Conventions eese eene nra enne nnn nint rennes 7 2 Welcome to the WLAN Application eeeeeeeeee 8 2 4 Starting the WLAN Application eeceeeeesseeeeeeseeeeene enne nnne nennen nnn nnn 9 2 2 Understanding the Display Information ceeeeennneennnnn nn 9 3 Measurements and Result Displays eese 12 3 1 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 12 3 2 Frequency Sweep Measurements ek NENNEN EEN 51 4 Measurement BASICS nica 57 4 1 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM j p A 57 4 2 Signal Processing for Single Carrier Measurements IEEE 802 11b g DSSS 64 43 Signal Processing for MIMO Measurements IEEE 802 11ac n 70 44 Channels and Carriers eerie eni neran eaaa Rn ERE EE
223. ement 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 Frequency Sweep Measurements 5 4 2 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 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 Table 5 3 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 select
224. ending 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 46 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 223 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 46 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Demo
225. enr aces verve e Eten 133 PPDU Format to Measures ro nenn eda Pha Ye Fere inn ies 133 Channel Bandwidth to measure CDW sse 134 MGS el OWS ERE ETE 134 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Pe NON ES 135 TBC AGU adc st 135 Extension Spatial Streams sounding 135 aote A ds 136 Guard MER e EE 136 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 228 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 t
226. ensdeunccabseduanceaeentencoseens 273 FETCH BURSEPAY Load MINIMUM A ssa ERR erre eere ety ent rt e ELATI e bte er Red 273 FETCH BURSEPAY L d AVERAGE KEE 273 FETCH BURStPEAK MAXIMUM E 273 FETCH BURSEPEAK MINIRIIUTI scai teer rp ee tr nee E Ry XR Ee eee Ne CEET 273 FETGI B RSEPEAKDAVERage titer er cda 273 FETCh BURSt PREamble MAXimum 2f FETCH BURSEPREAMBIE MINIMUM secos ERR ert erroe erect p Rer Ern SERA X ERE E NER ENTER T d 273 FETGIEB RSEPREambIe AVERage siria Rin uo EENS 273 FETCH BURSEQUADOTISEEAVERAG Lavarropas 274 FETCR BURSEQUADOffseE MAXIMUM i cac rre Aa 274 FETGCh BURSEQUADOffsetMINImUtTI cosmo eee trc rea E EO rear HR ER FERE 274 FETCh BURSERMS MJAXIIIUII soiree inseri era emere rk spoken Er bee BERN E ARE EENEN REO XXE TAL EENS 274 FETCh BURSt RMS MINimum 1 FETGh BURSERMSEAVERGa96 citro tort cere hr rx aa cea 274 FETCRh BURSES E 266 FETCH BURSUSYMBolenrorAVERAQ6 riir A ER pt 274 FETCh BURSt SYMBolerror MAXimum FETCh BURStSYMBoOlerror MINIMUM E 274 FETCHh BURSETFAUEAVERAG6 tette r tegere nee e ee Pv veter i tenn desee eap 274 FETGh B RSETFALEMADXIIUE cci rera corra eroe er e eee eeu toad E EAEE e Ree REESE e 274 IN ALEN GRO Ir ul 274 FETGI BURSETRIS amp AVERAge7 terere ray e rl a e CEPR ees ee dep b dg e TNR Ag 275 FETCh BURSEFRISe MAXIImUEnD ii seve tacencesedesesavseeadceessesatssoaescevaeatanesatentecdsesdtanenesnevas
227. er 3 2 Frequency Sweep Measurements on page 51 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 nz LUlMitcks ACPBowerACHannelbREzur 278 CAL Culate lt n gt LIMit lt k gt ACPower AL Temate chzREGu 278 CALCUS te lt gt BI e TE 279 CAL Culate nz M Abker mmzEUNGCHonP OWer zsbzHRESGu 280 CAL Gulate sm MARKerem X sensed a a eese tec a sr est end esten Paso aee sedit onry 282 GALGulat lt n gt STATistics RESUIt lt t gt c incccsasscescaetscsuacceneacedeaschtccueccoesaccneesctancuiccaeaa 282 CALCulate lt n gt LIMit lt k gt ACPower ACHannel RESult CALCulate lt n gt LIMit lt k gt 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 lt n gt lt k gt are irrelevant To get a valid result you have to perform a complete measurement with synchroniza tion to the end of the measurement before reading out the result This is only possible for single measurement mode See also INITiate lt n gt CONTinuous on page 261 Suffix lt ch gt 1 to 11 Alternate channel number Retrieving Results 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 ch
228. er Mode to External Select the STC MIMO tab in the General Settings dialog box 17 Select DUT MIMO configuration 2 Tx Antennas 18 Set the IP Address of the slave in the MIMO Measurement Setup table and turn the State of the slave to ON 10 10 1 10 1 1 10 1 2 Optimizing the Measurement Results Optimizing and Troubleshooting the Mea surement e Optimizing the Measurement Hesuhts 171 e Error Messages and Wamimngs AAA 172 Optimizing the Measurement Results If the results do not meet your expectations try the following methods to optimize the measurement IMPFOVING Performall6g eedem hebt rk EES 171 e Improving Channel Estimation and EVM ACcuracy 171 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 120 In this case the R amp S FPS 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 i
229. er measurements IEEE 802 11b g DSSS use PLCP Header IEEE 802 11b g DSSS instead 2 Signal Field Format MCS CBW HT SIG Len Sym SNRA STBC GI Ness Alst Alst Alst Estimatec t 1 1 Alst Fig 3 27 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 SS aa User Manual 1176 8551 02 06 46 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance The currently applied demodulation settings as defined by the user see chapter 5 3 9 Demodulation on page 123 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 j 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 124 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 payload in OFDM symbols P Parity bit Signal Tail Signal tail preset to 0 Table 3
230. eral digital standards and are often required in sig nal and spectrum test scenarios can be determined by the standard measurements provided in the R amp S FPS 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 l 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 The Frequency sweep measurements provided by the R amp S FPS WLAN application are identical to the corresponding measurements in the base unit but are pre configured according to the requirements of the selected WLAN 802 11 standard For details on these measurements see the R amp S FPS User Manual MSRA operating mode Frequency sweep measurements are not available in MSRA operating mode For details on the MSRA operating mode see the R amp S FPS MSRA User Manual The R amp S FPS WLAN application provides the following frequency sweep measure ments Measurement Types and Results for Frequency Sweep Measure ments The R amp S FPS WLAN application provides the following pre configured frequency Sw
231. eresis 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 e WMG GER OSC mE 83 E E A i a a aa aaa 84 e Tagger Drop OUt NEE 84 Tigger OIG E 85 e Trigger Synchronization Using the Master s Trigger Output 86 e Trigger Synchronization Using an R amp S FS Z11 Trigger Unit 86 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 FPS captures data continuously in the time domain even before the trigger occurs Triggered Measurements See Trigger Offset on page 111 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 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 lev
232. erformed 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 lt n gt SEQuencer MODE on page 262 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 FPS WLAN application are displayed in the eval uation bar in SmartGrid mode when you do one of the following 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 12 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 For details on working with the SmartGrid see the R amp S FPS 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 defaul
233. ermined 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 12 Parameters Limit 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 details on the UO offset and the default WLAN measurement see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 12 Parameters Limit 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 12 Parameters Limit numeric value in parts per million Default unit PPM Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 11 5 10 Automatic Settings d 11 5 11 MSRA operating mode In MSRA operating mode the following commands are not available as they require a new data acquisition Howe
234. error 1 Q offset 1 Q offset result Symbol clock error Symbol clock error result Lines METU aiis 91 Literature IEEE 802 118 9 OFDM Jy D nite 64 Log likelihood function IEEE 802 118 9 OFDM j p entes 61 Logica tilo ET 80 Long symbol LS JEEE 802 11a 9 OFDM j D iere 59 M Magnitude Capture Isesultdisplay ssec atico ente a exeun 35 Tirace data iii tene pe tete tee enean 287 Marker Functions METU oisin 91 Marker table Evaluation MEMO escoria 55 Markers Configuration remote esses Querying position remote Table evaluation method Maximizing Windows Remote gen eet tte aceite 245 Maximum YEOXIS PE 148 MCS index 12 128 129 134 135 Ice T 92 Displayed TE 10 Displayed information 130 136 Remolino es 228 Measurement channel Creating remote a se 180 181 183 Deleting remote AA 181 Duplicating remote ait tee 180 Querying remote 2 eet tt 181 Renaming remote A 182 Replacing remote esee 181 Selecting remote nitet cases 183 Measurement examples WEAN ee ac tire vert do e i end eas 164 Measurement time sock 202 Measurements Frequericy SWEEP rerai trei 51 RE TE RF types E Selecting E Selecting remote cuco nette eee 183 Setup displayed win 10 Starting remote
235. ers for IEEE 802 11a g OFDM j 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 11 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 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 ass
236. es which tab is displayed Parameters lt Format gt SPLit Displays the MultiView tab with an overview of all active chan nels SINGIe 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 249 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 Configuring the Result Display Example DISP WIND2 LARG 11 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 n always refers to the window in the currently selected measure ment channel see INSTrument SELect on page 183 LAYout ADD WINDOW cereo brennt tente e hann naaa 246 LAYOUECA Ta
237. etails on importing and exporting I Q data see the R amp S FPS User Manual MMEMONLOADACES TA rm 297 MMEM ry STOResn gt AQ STA Orinin eii ai 298 MMEMory LOAD IQ STATe 1 lt FileName gt This command restores UO data from a file 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 UO Import on page 158 Analysis MMEMory STORe lt n gt lQ STATe 1 lt FileName gt This command writes the captured UO data to a file The suffix lt n gt is irrelevant The file extension is iq tar By default the contents of the file are in 32 bit floating point format Secure User Mode In secure user mode settings that are to be stored on the instrument are stored to vol atile memory which is restricted to 256 MB Thus a Memory full error may occur although the hard disk indicates that storage space is still available To store data permanently select an external storage location such as a USB memory device For details see Protecting Data Using the Secure User Mode in the Data Manage ment section of the R amp S FPS User Manual Parameters 1 lt FileName gt String containing the path and name of the target file Example MMEM STOR IQ STAT 1 C R_S Instr user data ig tar Stores the captured UO data to the
238. evel detection Parameters for setting and query lt Mode gt ON Automatic power level detection is performed at the start of each measurement sweep and the reference level is adapted accord ingly OFF The reference level must be defined manually see DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel on page 199 ONCE Automatic power level detection is performed once at the start of the next measurement sweep and the reference level is adap ted accordingly RST ON Manual operation See Reference Level Mode on page 102 See Setting the Reference Level Automatically Auto Level on page 104 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Example CONF POW AUTO SWE TIME 0 01 MS 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 unit DBM Manual operation See Signal Level RMS on page 103 DISP
239. ever 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 independent 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 FPS User Manual The Sequencer functions are only available in the MultiView tab ele ui 90 Sequence Mole iiri ii 90 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 264 INITiate lt n gt SEQuencer IMMediate on page 262 INITiate lt n gt SEQuencer ABORt on page 262 Sequencer Mode Defines how often which measurements are performed The currently selected mode softkey 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 p
240. eving Results CALC LIM FAIL Queries the result of the limit check Result 0 passed TRAC DATA LIST Retrieves the peak list of the spectrum emission mask measurement Result 1 000000000 1 275000000E 007 8 500000000E 006 1 000000000E 006 2 108782336E 009 8 057177734E 001 7 882799530E 001 2 982799530E 001 0 000000000 0 000000000 0 00000000 2 000000000 8 500000000E 006 7 500000000E 006 1 000000000E 006 2 109000064E 009 8 158547211E 001 7 984169006E 001 3 084169006E 001 0 000000000 0 000000000 0 00000000 3 000000000 7 500000000E 006 3 500000000E 006 1 000000000E 006 2 113987200E 009 4 202708435E 001 4 028330231 E 001 5 270565033 0 000000000 0 000000000 0 000000000 Programming Examples R amp S FPS K91 Table 11 17 Trace results for SEM measurement 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
241. f 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 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 COUNt 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 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 sta
242. fault 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 198 Reference Level Reference Level Settings 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 This value is overwritten if Auto Level mode is turned on Remote command DISPlay WINDow lt n gt TRACe lt t gt 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 of
243. firmed Manual operation See Impedance on page 97 See Unit on page 103 INPut SELect Source This command selects the signal source for measurements i e it defines which con nector is used to input data to the R amp S FPS If no additional input options are installed only RF input is supported Tip The I 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 UO data from the WLAN application can be exported for further analysis in external applications See chapter 7 1 Import Export Functions on page 157 Parameters Source RF Radio Frequency RF INPUT connector RST RF Manual operation See Radio Frequency State on page 97 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 11 5 2 2 O 11 5 3 11 5 3 1 Configuring the Outputs Configuring trigger input output is described in Configuring the Trigger Output on page 208 DIAGnostic SERVICe NSOQVFGCB 1 1 ran arr er raro En dada dci cn 195 DIAGnostic SERVice NSOurce State This command turns the 28 V supply of the BNC connector labeled NOISE SOURCE CONTROL on the R amp S FPS on and off For details see chapter 4 7 1 Input from Noise Sources on page 81 Parameters State ON OFF RST OFF Example DIAG SERV NSO ON Manual operation See
244. for the IEEE 802 11b standard This result is the value before filtering For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 12 Usage Query only FETCh BURSt CFERror AVERage FETCh BURSt CFERror MAXimum FETCh BURSt CFERror MINimum 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 12 Return values lt Result gt lt Global Result gt lt Stream 1 result gt lt Stream n result gt 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 12 Usage Query only 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 12 Usage Query only Retrieving Results 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 F
245. fset if the signal is attenuated or amplified before it is fed into the R amp S FPS so the application shows correct power results All displayed power level results will be shifted by this value 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 FPS 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 FPS increases the displayed power values a negative value indicates an external gain R amp S FPS decreases the displayed power values The setting range is 200 dB in 0 01 dB steps Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel OFFSet on page 199 Unit Reference Level Settings The R amp S FPS 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 O or 75 Q see Impedance on page 97 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 194 CALCulate lt n gt UNIT POWer on page 198 Setting the Reference Level Automatically Auto Level Reference Level Set tings Au
246. ft 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 FPS K91 Measurement Basics Tracking the phase drift timing jitter and gain Referring to the IEEE 802 11a g OFDM j p measurement standard chapter 17 3 9 7 Transmit modulation accuracy test 6 the common phase drift phase mon 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 FPS WLAN application see Phase Tracking on page 122 Furthermore the timing drift in FFT is given by phase 2gx N I 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 symbol errors The example shows that it is actually necessary to estimate and compensate the clock deviation which is accomplished in the next block
247. g gered due to a measurement start Device Triggered or when the R amp S FPS is ready to receive a trigger signal after a measurement 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 provided o Providing trigger signals as output is described in detail in the R amp S FPS User Manual 4 8 Preparing the R amp S FPS for the Expected Input Signal Frontend Parameters On the R amp S FPS 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 FPS s hardware to the expected maximum signal level by setting the Reference Level to this maximum Compensate for any external attenuation or gain by defining a Reference Level offset
248. g the INITiate n IMMediate command Usage Event Manual operation See Gain Imbalance vs Carrier on page 33 Selecting a Measurement 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 33 See Phase Error vs Preamble on page 37 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 187 Parameters lt ErrType 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 33 See Phase Error vs Preamble on page 37 CONFigure BURSt PTRacking IMMediate This remote control command configures the measurement type to be Phase Tracking vs Symbol Manual operation See Phase Tracking on page 37 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 39 See PvT Rising Edge on page 40 See PvT
249. ge lt RBW gt resolution bandwidth lt PeakFreq gt frequency of the peak in a range lt PowerAbs gt absolute power of the peak in dBm PowerRel 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 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 Retrieving Results Parameters lt OffsetSamp gt Offset of the val
250. gs The R amp S FPS can provide output to special connectors for other devices For details on connectors refer to the R amp S FPS Getting Started manual Front Rear Panel View chapters o How to provide trigger signals as output is described in detail in the R amp S FPS 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 Trigger 2 NOS DOC cui 98 TIT E 99 L Output AA A A 99 uo AA 99 ER 100 BE o WI NER 100 Noise Source Switches the supply voltage for an external noise source on the R amp S FPS on or off if available External noise sources are useful when you are measuring power levels that fall below the noise floor of the R amp S FPS itself for example when measuring the noise level of a DUT WLAN IQ Measurement Modulation Accuracy Flatness Tolerance For details see chapter 4 7 1 Input from Noise Sources on page 81 Remote command DIAGnostic SERVice NSOurce on page 195 Trigger 2 Defines the usage of the variable TRIGGER AUX 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 FPS User Manual Input The signal at the connector is used as an external trigger source by the R amp S FPS No further trigger parameters are available for the con nector Output The R amp S FPS sends a trigger signal to t
251. gs for the following measurements are available via the Overview e Channel Power ACLR Measurements AAA 152 e Spectrum Emission Mask eiecit ici 153 e JQOccupled Bandwidth ei ie hav eec ene dod sea SEN 154 MES CD A E rS 154 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 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 2 Predefined settings for WLAN ACLR Channel Power measurements Setting Default value ACLR Standard same as defined in WLAN signal descrip tion see Standard on page 95 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 FPS User Manual To restore adapted measurement parameters the following parameters are saved on exiting and are restored on re entering this measur
252. hapter 5 3 5 Signal Capture Data Acquisition on page 105 5 Synchronization OFDM demodulation See chapter 5 3 7 Synchronization and OFDM Demodulation on page 119 6 Tracking Channel Estimation See chapter 5 3 8 Tracking and Channel Estimation on page 120 7 Demodulation See chapter 5 3 9 Demodulation on page 123 8 Evaluation Range See chapter 5 3 10 Evaluation Range on page 138 9 Display Configuration See chapter 5 2 Display Configuration on page 91 To configure settings P Select any button in the Overview to open the corresponding dialog box Preset Channel Select the Preset Channel button in the lower lefthand corner of the Overview to restore all measurement settings in the current channel to their default values Note that the PRESET key restores the entire instrument to its default values and thus closes all measurement channels on the R amp S FPS except for the default Spectrum application channel See chapter 5 3 1 Default Settings for WLAN Measurements on page 92 for details Remote command SYSTem PRESet CHANnel EXECute on page 183 Select Measurement Selects a measurement to be performed See Selecting the measurement type on page 89 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 Sel
253. he INITiate n IMMediate command Usage Event Manual operation See Bitstream on page 24 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 lt n gt IMMediate command Usage Event Manual operation See PLCP Header IEEE 802 11b g DSSS on page 38 See Signal Field on page 46 DISPlay WINDow lt n gt SELect This command sets the focus on the selected result display window This window is then the active window Selecting a Measurement Example DISP WIND1 SEL Sets the window 1 active Usage Setting only 11 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 51 The selected measurement must be started explicitely see chapter 11 8 Starting a Measurement on page 259 CONFloure BURG GE Cirum AC IMMedlatel nenne 190 CONFigure BURSt SPECtrum MASK IMMediate sees 190 CONFloure BURG GE Cirum OBVWid t IMMedlatel rriei inniinn niania 190 CONFigure BURStSTATistics CCDF IMMediate sess 191 CONFigure BURSt SPECtrum ACPR IMMediate This remote control command configures the
254. he 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 46 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 226 SENSe DEMod FORMat BANalyze on page 225 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 following description indicate how the setting is referred to in the Signal Field result display CBW column see Signal Field on page 46 Auto same type as first PPDU A1st The channel bandwidth of the first valid PPDU is detected and subse quent PPDUs are analyz
255. he DUT is connected to the R amp S FPS using the RF input of the R amp S FPS The DUT generates a signal modulated using 16QAM e Measurement Example Setting up a MIMO measurement eeren 164 9 1 Measurement Example Setting up a MIMO measure ment For this example a 2 Tx MIMO DUT according to IEEE 802 11n is used 1 The MIMO DUT is connected to the analyzers according to the following setup Trigger Signal RF Signal LAN Reference Signal 2 Connect the external reference REF OUT of the SMU with the external reference REF IN of the analyzers Switch on the external reference for both analyzers in the spectrum analyzer base system 3 Connect the marker output of the SMU with the EXT TRIGGER input of the ana lyzers 4 Either connect the Path A RF Baseband connector with one analyzer and the Path B RF Baseband connector with the other analyzer or use the air interface with appropriate antennas Measurement Example Setting up a MIMO measurement 5 Connect the master and the slave anaylzer via LAN according to the figure above As an alternative it is sufficient to connect master and slave with a cross LAN cable The analyzer with the R amp S FPS K91n option can be used as master The slave analyzer does not require a WLAN option 6 Setup the SMU to generate a 2 Tx IEEE 802 11n MIMO signal For the SMU Baseband A select the IEEE 802 11n option This opens the IEEE 802 11n WLAN A dialog A red 2
256. he 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 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 FPS 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 FPS product page at http www2 rohde schwarz com product FPS html 1 3 Typographical Conventions Service Manual This manual is available in PDF format on the Documentation CD ROM delivered with the instrument It describes how to check compliance with rated specifications instru ment function repair troubleshooting and fault elimination It contains all information required for repairing the R amp S FPS by replacing modules Release Notes The release notes describe the installation of the firmware new and modified func tions eliminated problems and last minute changes to the documentation The corre sponding firmware version is indicated on the title page of the release notes The most recent release notes are also available for download from the Rohde amp Schwarz website on the R amp S FPS product page at http www2 rohde schwar
257. he following evaluation methods A 22 AMPM 23 AE EE 23 SUSUR AND EE 24 Constellation best a bana Lee ente e den etd e dad Ee re i 26 Constellation vs Came EEN 28 EVM VS e 29 EE o E 30 EVM VS SIDO SSG 30 FET SPECON EE 31 Freg Emor ys Preamble eroe reete x E Nott RE He nexa 3k deossnananaensaderasesteacsanaedacnaanes 33 Gain Imbalance VS CAM i e c ra e E Rer c rt e c nea e 33 Group Delay E 34 Magnitude CIRIO von tx aset esiste EES 35 Phase Error vs bDreamble 37 Phase Nee e EE 37 PLOP Header IEEE 802 e 9 E DEE 38 R amp S FPS K91 Measurements and Result Displays IEN E PROU minoorne EE 39 PVT RENO BO GG If P 40 PVE Falling BOG Gi LEER 41 Quad Emor vs Tu EE 42 Result Summary Detalled 2 e ramen pas 43 Result Summary Global ui ei i QN ead E aac 44 epi 46 Spectrum EE EE 49 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 c
258. he memory After lt x gt measurements the oldest results in the memory are overwritten by each new measure ment The number of results in the memory to be considered is config urable see DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO MEMor y DEPTHh RST HYSTeresis Example DISP WIND2 TRAC Y AUTO MODE MEM Manual operation See Auto Mode on page 147 DISPlay WINDow lt n gt TRACe lt t gt X SCALe DIVisions lt NoDivisions gt DISPlay WINDow lt n gt TRACe lt t gt Y SCALe DIVisions lt NoDivisions gt Defines the number of divisions to be used for the x axis or y axis in the specified win dow Separate division settings can be configured for individual result displays Parameters lt NoDivisions gt Example DISP WIND2 TRAC Y SCAL DIV 10 Manual operation See Number of Divisions on page 149 DISPlay WINDow lt n gt TRACe lt t gt X SCALe MAXimum Max DISPlay WINDow lt n gt TRACe lt t gt Y SCALe MAXimum Max Defines the minimum value to be displayed on the x axis or y axis of the specified eval uation diagram For automatic scaling with a fixed range see DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO FIXed RANGe on page 255 the minimum defines the fixed lower limit Parameters Max Starting a Measurement Example DISP WIND2 TRAC Y SCAL MAX 100 Manual operation See Minimum Maximum on page 148 DISPlay WINDow lt n gt TRA
259. he output connector to be used by connected devices Further trigger parameters are available for the connector Note For simultaneous MIMO measurements see Simultaneous Signal Capture Setup on page 114 if you set the master s TRIGGER 2 INPUT OUTPUT connector to device triggered output the master R amp S FPS sends its trigger event signal to any connected slaves See also chapter 4 9 5 Trigger Synchronization Using the Master s Trigger Output on page 86 Remote command OUTPut TRIGger lt port gt LEVel on page 208 OUTPut TRIGger lt port gt DIRection on page 208 Output Type Trigger 2 Type of signal to be sent to the output Device Trig Default Sends a trigger when the R amp S FPS triggers gered Trigger Sends a high level trigger when the R amp S FPS is in Ready for trig Armed ger state This state is indicated by a status bit in the STATus OPERation reg ister bit 5 User Defined Sends a trigger when user selects Send Trigger button In this case further parameters are available for the output signal Remote command OUTPut TRIGger lt port gt OTYPe on page 209 Level Output Type Trigger 2 Defines whether a constant high 1 or low 0 signal is sent to the output connector Remote command OUTPut TRIGger lt port gt LEVel on page 208 5 3 4 3 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Pulse Length Output Type Trigger 2 Defines the
260. he trigger source is indicated Remote command TRIGger SEQuence SOURce on page 207 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 207 External Trigger 1 2 Trigger Source Trigger Source Settings Data acquisition starts when the TTL signal fed into the specified input connector meets or exceeds the specified trigger level See Trigger Level on page 110 Note The External Trigger 1 softkey automatically selects the trigger signal from the TRG IN connector For details see the Instrument Tour chapter in the R amp S FPS Getting Started manual External Trigger 1 Trigger signal from the TRG IN connector External Trigger 2 Trigger signal from the TRG AUX connector Note Connector must be configured for Input in the Outputs con figuration see Trigger 2 on page 99 Remote command TRIG SOUR EXT TRIG SOUR EXT2 See TRIGger SEQuence SOURce on page 207 RF Power Trigger Source Trigger Source Settings Defines triggering of the measurement via signals which are outside the displayed measurement range WLAN IQ Measurement Modulation Accuracy Flatness Tolerance For this purpose the instrument uses a level detector at the first intermediate fre quency The inp
261. ic Modulation Accuracy Flatness and Tolerance Results 265 e Numeric Results for Frequency Sweep Measurements coccccnccnnonoononcnnccnnnnncaninns 278 e Rettieving Trace E 283 e Measurement Results for TRACe lt n gt DATA TRACE ns eene 287 e Importing and Exporting UO Data and Resuhts sss 297 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 11 9 2 Numeric Results for Frequency Sweep Measure ments on page 278 e PPDU and Symbol Court Results occiso ete en ens 265 e Error Parameter Results tee ia teet ert 267 e Limit Check Results toi a diia 275 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 I Q data see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 12 FETCIIBURSE RT EE 266 FEIGIYBURSECODUNEALDIS E 266 EE OR e el ia 266 FETGIYXBURSELENGIIS etr re ENEE EENS Ae 266 a ER NR iine ne etate id TEE ERES PEE eines 266 UNT BURSE EE 267 Retrieving Results FETCh BURSt COUNt This command returns the number of analyzed PPDUs from the current capture buffer I
262. ication 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 1176 8551 02 06 74 R amp S FPS K91 Measurement Basics EH 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 FPS 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 Tip Use the master s trigger output see chapter 4 9 5 Trigger Synchronization Using the Master s Trigger Output on page 86 or an R amp S Z11 trigger box see chapter 4 9 6 Trigger Synchronization Using an R amp S FS Z11 Trigger Unit on page 86 to send the same trigger signal to all devices 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 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 ma
263. ilot 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 122 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 0 1 RST 0 Example SENS TRAC TIME ON Manual operation See Timing Error Tracking on page 122 11 5 7 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 see CONFigure STANdard on page 191 Manual configuration is described in chapter 5 3 9 Demodulation on page 123 GCONFigure WLAN EXTensiomAUTO TYBE i rie ri iii 218 CONFigure WLAN GTIMe AUTO ssssssssssssseete sehen nenne enne nnns eser tr trs rt rtr rr nnns 218 GCONFigure WLEAN GTIM amp AUTO TYPE acia ici encore cette ite exa ecco AEN 219 CON Figure WEANEGTIMS SEBEBQL torte repe REPRE RR Den SE areis 220 CONFloure WAN SMAbpoing MODE nono nn 221 CONFigure WLAN SMAPping NORMalise cesses ener nnne 221 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance CONFigure WLADESMAP DIN
264. indow In the default state the name of the window is its index numeric value Index of the window LAY CAT Result Via t pam E d Two windows are displayed named 2 at the top or left and 1 at the bottom or right Query only LAYout IDENtify WINDow lt WindowName gt This command queries the index of a particular display window in the active measure ment channel Configuring the Result Display Note to query the name of a particular window use the LAYout WINDow lt n gt IDENtify query Query parameters lt WindowName gt String containing the name of a window Return values Windowlndex Index number of the window Usage Query only LAYout REMove WINDow lt WindowName gt This command removes a window from the display in the active measurement channel Parameters lt WindowName gt String containing the name of the window In the default state the name of the window is its index Usage Event LAYout REPLace WINDow lt WindowName gt lt WindowType gt This command replaces the window type for example from Diagram to Result Sum mary of an already existing window in the active measurement channel while keeping its position index and window name To add a new window use the LAYout ADD WINDow command Parameters lt WindowName gt String containing the name of the existing window By default the name of a window is the same as its index To determine the
265. indow type 3 Trace color 4 Trace number 6 Trace mode Diagram footer information The diagram footer beneath the diagram contains the start and stop values for the displayed 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 FPS 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 89 e WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 12 e Frequency Sweep Measurements E 51 3 1 WLAN UO Measurement Modulation Accuracy Flat ness and Tolerance The default WLAN I Q measurement captures the I Q 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 FPS WLAN application to demodulate broadband signals and determine various characteristic sig nal parameters such as the modulation accuracy spectrum f
266. inn EE ee le e E CONFigure BURSEPV T RROWGR geed EUREN ECKE ia AAA EE e e UI e AE GONFigure BURSEPVT D IMMediate orent erg ero cris CONFigure BURSCTQUAD QCARrier MMediate AAA CONFigure BURSt SPECtrum ACPR MMediate GONFigure BURStSPECtr m FF T IMMediate nnt oett tm erar tecnica ay CONFigure BURStSPECtrum FLATness CSELect ccoo etn rn trennen rn repa ii GONFigure BURStSPECtr m FLATness SELect rrt nrbe erri Rh is CONFigure BURSt SPECtrum FLATness IMMediate CONFigure BURSt SPECtrum MASK IMMediate 25227 it tne t tnit het hr CONFigure BURSt SPECtrum OBWidth IMMediate eese nennen CONFigure BURSt STATistics BSTReam I MMediate CONFigure BURStSTATistics CCDF IMMediate rrt tnter te rre tnn CONFigure BURSEtSTATistics SFleld IMMediate cesses CONElgure POWer AU TO oscar AT CONFigure POWer AUTO SWEep TIME t tton rrr rh re toe TA riera aeea GONFigure POWerEXPected RF nire mre rn ic n EH ea Ere RENNE RE RR E Eee CONFIQUE STAING ANG 5 E CONFigure WLAN ANTMatrix ADDResS lt add gt occcioccococccoccconccnonannnncnanncnnncnnnc cnn nono n cono nc can nn anna nn nc nn arc n nan ncne CONFoure WAN ANTMatrtv ANTenna Analyzerz canon ccoo na nro r nana ran crac nani CONFigure WLAN ANTMatrix SOURce ROSCillator SOURce
267. ion dialog box depends on the standard you selected previously for the WLAN Modulation Accuracy Flatness measurement see Standard on page 95 E 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 FPS 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 5 4 4 Frequency Sweep Measurements Occupied Bandwidth The Occupied Bandwidth measurement is performed as in the Spectrum application with default settings Table 5 4 Predefined settings for WLAN 802 11 OBW measurements Setting Default value Power Bandwidth 99 Channel bandwidth 3 84 MHz The Occupied Bandwidth measurement 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 The OBW measurement can be configured in the OBW tab of the Analysis dialog box available from the WLAN
268. ion of the individual measurement functions for details 2 Result Summary Channel Bandwidth Offset Power TX1 Ref MHz 0 86 dBm 0 86 dBm Offset Lower Jpper 50 000 kHz 79 59 dB 80 34 dB 980 MHz 85 04 dB 83 85 dB Remote command LAY ADD 1 RIGH RSUM See LAYout ADD WINDow on page 246 Marker Table Displays a table with the current marker values for the active markers 4 Marker Table Wnd Type X value 1 13 25 GHz 600 0 kHz 1 M 1 Mi 600 0 kHz 1 Ye V 2 0 MHz Remote command LAY ADD 1 RIGH MTAB see LAYout ADD WINDow on page 246 Results CALCulate n MARKercm X on page 282 CALCulate n MARKercm Y on page 299 User Manual 1176 8551 02 06 55 R amp S FPS K91 Measurements and Result Displays 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 2 Marker Peak List No 1 Remote command LAY ADD 1 RIGH PEAK see LAYout ADD WINDow on page 246 Results CALCulate lt n gt MARKer lt m gt X on page 282 CALCulate lt n gt MARKer lt m gt Y on page 299 User Manual 1176 8551 02 06 56 4 4 1 4 1 1 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM j
269. iple analyzers see Simultaneous Signal Capture Setup on page 114 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 l Q data at the same time Compared to using the master s trigger out function using the Trigger Unit pro R amp S FPS K91 Measurement Basics vides a more accurate synchronisation of the slaves However it requires the addi tional hardware 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 Unit s 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 available 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 simult
270. 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 in the demodulation settings of the application Signal Processing for Single Carrier Measurements IEEE 802 11b g DS
271. it check The limit value is defined by the standard or the user see CALCulate LIMit BURSt FERRor MAXimum 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 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 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 11 9 2 Retrieving Results 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 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 Numeric Results for Frequency Sweep Measurements The following commands are required to retrieve the numeric results of the WLAN fre quency sweep measurements see chapt
272. itstream is NOT channel decoded For multicarrier measurements IEEE 802 11a g OFDM ac j n p the results are grouped by symbol and carrier SSS ee aa User Manual 1176 8551 02 06 24 R amp S FPS K91 Measurements and Result Displays 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 grouped by stream sym bol and carrier Stream 1 4 Stream 1 Stream2 Stream 3 Stream 4 3 2 Stream 2 Symbol 1 gt Carrier Symbol 1 01001010 10010110 01110110 122 11001110 11100000 01110011 11111101 10010010 01110101 119 10100111 01100010 11100001 10010011 00110000 10000110 116 01000011 01110001 00101110 11000101 00010010 01111110 113 10110010 10000100 10011010 10010101 00100101 10100100 110 11100110 11111110 11101101 10001011 00011011 01001010 107 10001111 01110101 01111010 10100100 0 10111101 104 00001001 0 11011100 00111000 10101111 10110011 d 101 11100010 00110011 10101111 3 3 Stream 3 3 4 Stream 4 Carrier Symbo
273. ized and tracked separately Remote command CONFigure WLAN RSYNc JOINed on page 213 Sequential Using OSP Switch Setup A single analyzer and the Rohde amp Schwarz OSP Switch Platform with at least one fitted R amp S amp OSP 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 75 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 R amp S FPS K91 Configuration Uu on NE Signal Capture Trigger Source Trigger In Out MIMO Capture DUT MIMO Config 3 Tx Antennas gt MIMO Antenna Signal Capture Setup Simultaneous Sequential using OSP Switch Box Sequential Manual OSP Switch Box Setup OSP Switch Bank Configuration 3 TX Antenna DUT Connecting 3 RF antenna s via an OSP Switch Box to the Analyzer Fig 5 1 Connection instructions for sequential MIMO using an OSP switch The diagram shows an R amp S amp 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 indi
274. l RALL PPDU power RPPower Crest factor RCFactor Bitstream Stream All SALL Pilot bit error rate BPILot EVM all carriers SEACarriers EVM data carriers SEDCarriers EVM pilot carriers SEPCarriers Table 11 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 Center frequency error CFERror Symbol clock error SCERror 11 7 4 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 User Manual 1176 8551 02 06 253 11 7 5 Configuring the Result Display
275. l 1 zi Carrier Symbol 1 122 11001101 00100011 11001110 122 01001101 00111101 10111011 119 11101001 10101000 00010010 119 11100110 00000111 00001011 116 00000001 00101101 10100010 116 01110110 00001011 01011101 113 01010001 10011000 00010010 113 00110011 00010010 01101101 110 10000010 11101011 11100100 110 01000000 00011101 107 01001111 11101100 11001101 107 11100010 01000010 01000111 104 10010001 o 01010000 104 00111110 0 11001001 int 00000111 00101101 01010011 a 101 01001111 11001101 01001101 Fig 3 8 Bitstream result display for IEEE 802 11n MIMO measurements User Manual 1176 8551 02 06 25 R amp S FPS K91 Measurements and Result Displays WEEN For single carrier measurements IEEE 802 11b g DSSS the results are grouped by PPDU 4 Bitstream PPDU 1 PLCP Preamble 0 24 48 72 96 120 PLCP Header 0 24 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 Fig 3 9 Bitstream result display for IEEE 802 11b g DSSS standards The numeric trace results for this evaluation method are described in chapter 11 9 4 4 Bitstream on page 290 Remote command LAY ADD 1 RIGH BITS see LAYout ADD WINDow on page 246 or CONFigure BURSt STATi
276. latness center frequency tolerance and symbol clock tolerance in just one measurement Other 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 see chapter 3 2 Frequency Sweep Mea surements on page 51 e Modulation Accuracy Flatness and Tolerance Parameters sssss 12 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 j n p Parameter Description General measurement parameters Sample Rate Fs Input sample rate PPDU Type of analyzed PPDUs MCS Index Modulation and Coding Scheme MCS index of the analyzed PPDUs GI Guard interval length for current measurement Standard Selected WLAN measurement standard the limits can be changed via remote control not manually see chapter 11 5 9 Limits on page 237 in this case the currently defined limits are displayed here WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Parameter Description Meas Setup Number of Transmitter Tx and Receiver Rx channe
277. lay WINDow lt n gt TRACe lt t gt Y SCALe MAXimum on page 258 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe MINimum on page 259 Memory Depth For automatic scaling based on memory this value defines the number lt x gt of previous results to be considered when determining if rescaling is required WLAN IQ Measurement Modulation Accuracy Flatness Tolerance The minimum and maximum value of each measurement are added to the memory After lt x gt measurements the oldest results in the memory are overwritten by each new measurement If the maximum value in the current measurement exceeds the maximum of the lt x gt previous results and the upper limit is not fixed the x axis or y axis is rescaled If the minimum value in the current measurement drops below the minimum of the lt x gt previous results and the lower limit is not fixed the x axis or y axis is rescaled Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO MEMory DEPTh on page 257 Number of Divisions Defines the number of divisions to be used for the x axis or y axis Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe DIVisions on page 258 Scaling per division Determines the values shown for each division on the x axis or y axis One or more multiples of 10 can be selected Example Multiples of 2 0 and 2 5 selected n 1 division range 0 1 0 0 2 0 25 0 4 0 5 0 6 0 75 0 8 1 0
278. lay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel lt ReferenceLevel gt This command defines the reference level for all traces lt t gt is irrelevant Example DISP TRAC Y RLEV 60dBm Usage SCPI confirmed Manual operation See Reference Level on page 103 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe RLEVel OFFSet Offset This command defines a reference level offset for all traces lt t gt is irrelevant 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 103 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 Parameters lt Attenuation gt Range see data sheet Increment 5dB RST 10 dB AUTO is set to ON Example INP ATT 30dB Defines a 30 dB attenuation and decouples the attenuation from the reference level Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Usage SCPI confirm
279. length of the pulse sent as a trigger to the output connector Remote command OUTPut TRIGger lt port gt PULSe LENGth on page 209 Send Trigger Output Type Trigger 2 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 209 Frequency Settings Frequency settings for the input signal can be configured via the Frequency dialog box which is displayed when you do one of the following Select the FREQ key and then the Frequency Config softkey e Select Input Frontend from the Overview and then switch to the Frequency tab Stepsize 1 0 MHz Freque Value CONSTE T m 100 Center Frequency Stepslze EE 101 Frequency en E 101 Center frequency Defines the normal center frequency of the signal fmax and SPAN pin depend on the instrument and are specified in the data sheet Remote command SENSe FREQuency CENTer on page 195 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Center Frequency Stepsize Defines the step size by which the center frequency is incre
280. les R amp S FPS K91 11 13 Programming Examples R amp S FPS 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 308 e Measurement 2 Determining the Spectrum Emission Mask 311 11 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 fg 2z Preparing the application Preset the instrument RST Enter the WLAN option K91n INSTrument SELect WLAN Switch to single sweep mode and stop sweep INITiate CONTinuous OFF ABORt 9592295 2 2 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 PERRAS Signal description Use measurement standard IEEE 802 Lin CONF STAN 6 Center frequency is 13 25 GHz FREQ CENT 13 25GHZ 5 252 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
281. lex 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 1176 8551 02 06 72 Signal Processing for MIMO Measurements IEEE 802 11ac n Tx Stream T STS l 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 the spatial mapping 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 format PPDU 1 4 DataHT LTFs Extension HT LTFs 8 8 8 3 3 3 3 3 3 El El El El EZ El ef El El ge go at Ge Gt Gat Qt Gy at N N N HT greenfield format PPDU 1 3 Data H
282. log WINDOW KEE 248 de De RTE 248 LAYout REMove WINDOW ccccecececee cece eaeee eee ee eee aaa teceteeeeeeeeeeeeeeseeeesesesesasaeaaaaaeaaaaaaeees 249 LAY ouEREPLacep WIND rtt rti decd tree cde rotat ex o eyed egeo xe eet regat eade rn 249 LAYOUES PLA EM T 249 LAYOVEWINDOW NA ADD Mem Em 251 LAYoutiWINDow lt n gt IDENGfy c0 cecctecceanseesenssssavesedeedapetetecisgeaeaeetiagtenedestareserssanaeeteds 251 Bd e uk ee 252 LAYOUT WINDOWSA REPLACE T 252 LAYout ADD WINDow lt WindowName gt lt Direction gt lt WindowType gt This command adds a window to the display in the active measurement channel This command is always used as a query so that you immediately obtain the name of the new window as a result To replace an existing window use the LAYout REPLace WINDow command Parameters lt WindowName gt String containing the name of the existing window the new win dow is inserted next to By default the name of a window is the same as its index To determine the name and index of all active windows use the LAYout CATalog WINDow query lt Direction gt LEFT RIGHt ABOVe BELow Direction the new window is added relative to the existing win dow lt WindowType gt text value Type of result display evaluation method you want to add See the table below for available parameter values Return value
283. ls outside the usable I Q bandwidth passband are suppressed Usually the suppressed signals are noise artifacts and the second IF side band If frequencies of interest to you are also suppressed you should try to increase the output sample rate since this increases the maximum usable UO band width Bandwidth extension options E The maximum usable UO bandwidth provided by the R amp S FPS in the basic installation can be extended by additional options These options can either be included in the ini tial installation B options or updated later U options The maximum bandwidth provi ded by the individual option is indicated by its number for example B40 extends the bandwidth to 40 MHz As a rule the usable UO bandwidth is proportional to the output sample rate Yet when the UO bandwidth reaches the bandwidth of the analog IF filter at very high output sample rates the curve breaks e Bandwidth Extension Optons nennen nnn 314 e Relationship Between Sample Rate and Usable UO Bandwidth 314 e Relationship Between Sample Rate Record Length and Usable UO Bandwidth 314 e R amp S FPS without additional bandwidth extension options suse 315 e R amp S FPS with option B40 I DQ Bandwidth Extension 316 e R amp S FPS with activated option B160 I Q Bandwidth Extension 316 Sample Rate and Maximum Usable UO Bandwidth for RF Input A 1 1 Bandwidth Extension
284. ls 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 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 in physical chan nel TX and Rx carrier parameters 1 Q offset dB Transmitter center frequency leakage relative to the total Tx channel power see chapter 3 1 1 1 1 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 16 Quadrature offset Deviation of the quadrature phase angle from the ideal 90 see chap ter 3 1 1 3 Quadrature Offset on page 17 UO skew s Delay of the transmission of the data on the path compared to the Q path see chapter 3 1 1 4 I Q Skew on page 18 PP
285. lt will be too long to display in IECWIN but is stored in log file 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 Programming Examples R amp S FPS K91 Zieser Exporting Captured I Q Data Store the captured I Q data to a file MMEM STOR IQ STAT 1 C R_S Instr user data ig tar 11 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 fg 2 Configuring the measurement DISP TRAC Y SCAL KLEV 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 a 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 p REseeEERREE Retri
286. ly valid after a single measurement end synchronization For details on synchronization see the Remote Basics chapter in the R amp S FPS User Manual If the measurement mode is changed for a measurement channel while the Sequencer is active see INITiate lt n gt SEQuencer IMMediate on page 262 the mode is only considered the next time the measurement in that channel is activated by the Sequencer Suffix n irrelevant Parameters State ON OFF 0 1 ON 1 Continuous measurement OFF 0 Single measurement RST 0 Example INIT CONT OFF Switches the measurement mode to single measurement INIT CONT ON Switches the measurement mode to continuous measurement Manual operation See Continuous Sweep RUN CONT on page 150 INITiate lt n gt 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 FPS User Manual Starting a Measurement Suffix lt n gt irrelevant Usage Event Manual operation See Single Cont on page 118 See Single Sweep RUN SINGLE on page 150 INITiate lt n gt SEQuencer ABORt This command stops the currently active sequence of measurements The Sequencer itself is not deactivated so you can start a new sequence immediately using INITiate lt n gt SEQuencer IMMediate on page 262 To deactivate the Sequencer use SYSTem
287. m 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 I Q Measurement Modulation Accuracy Flat ness and Tolerance on page 12 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 151 The settings required to configure each of these measurements are described here Selecting the measurement type gt 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 Pressthe MEAS key In the Select Measurement dialog box select the required measurement e Multiple Measurement Channels and Sequencer Function ssss 89 e Ee Tt EE EN e WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 91 e Frequency Sweep Measurements ener 151 Multiple Measurement Channels and Sequencer Function When you activate an application a new measurement channel is created which deter mines the measurement settings for that application 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 wan
288. master to send its reference frequency to all slave devi ces via one of its REF OUTPUT connectors See the R amp S FPS User Manual for details Off Both the master and slave devices use their own internal references the frequencies are not coupled Remote command CONFigure WLAN ANTMatrix SOURce ROSCillator SOURce on page 210 5 3 6 Application Data MSRA For the R amp S FSW WLAN application in MSRA operating mode the application data range is defined by the same settings used to define the signal capturing in Signal and Spectrum Analyzer mode see chapter 5 3 5 Signal Capture Data Acquisition on page 105 In addition a capture offset can be defined i e an offset from the start of the captured data to the start of the analysis interval for the WLAN 802 11 I Q measurement see Capture Offset on page 106 The analysis interval cannot be edited manually but is determined automatically according to the selected channel carrier or PPDU to analyze which is defined for the evaluation range depending on the result display Note that the channel carrier PPDU is analyzed within the application data 5 3 7 Synchronization and OFDM Demodulation Synchronization settings have an effect on which parts of the input signal are pro cessed during the WLAN measurement 5 3 8 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Synchronization Power Interval Search OFDM Demodulation Power Interval DEE
289. mats 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 46 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 226 SENSe DEMod FORMat BANalyze on page 225 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 dep
290. maxi mum likelihood algorithm is used In the first estimation step the symbol independent parameters A fest and E are estimated The symbol dependent parameters can be User Manual 1176 8551 02 06 61 Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM j p 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 L Af es gt y k 21 7 7 21 imi 2 E pp common timing LS J phase phase y Nae Ay xH xe with phase 25x N IN Af T xl phase 9 225 x N 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 Af 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 d TM A WE common ti min g LS _ J Bhasd phase ny a Xg xH xe Ly g dy 3 k 21 7 7 21 with Phase 2xN INxMf T xl dy phase 9 225 x N N x xkxl Log likelihood function step 2 4 5 Finally the trial parameters leading to the minimum of the log likelihood function are
291. me insight in modulation quality and enables comparisons to other modulation standards Q Fig 3 6 l 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 calculation 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 FPS WLAN application nor malizes 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 3596 In contrary to the specification the R amp S FPS WLAN application does not limit the mea surement to 1000 chips length but searches the maximum over the whole PPDU WLAN UO Measurement Modulation Accuracy Flat
292. meshift 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 138 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 129 DO D1 D2 Demod all as STBC field 0 1 2 For details see STBC Field on page 129 Example CONF WLAN STBC AUTO TYPE MO Manual operation See STBC Field on page 129 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 FPS bandwidth exte
293. meters lt State gt 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 121 SENSe TRACking CROSstalk lt State gt Activates or deactivates the compensation for crosstalk between MIMO carriers This command is only available for standard IEEE 802 11ac or n MIMO Parameters lt State gt ON OFF RST OFF Example SENS TRAC CROS ON Manual operation See Compensate Crosstalk MIMO only on page 123 SENSe TRACking IQMComp 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 18 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 l Q skew impairments is applied OFF Compensation is not applied this setting is required for mea surements strictly according to the IEEE 802 11 2012 IEEE 802 11ac 2013 WLAN standard RST OFF Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Manual operation See Q Mismatch Compensation on page 122 SENSe TRACking LEVel lt State gt Activates or deactivates the compensation for level variati
294. meters can be changed in advance using UNIT EVM on page 275 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 12 Parameters Limit numeric value in dB The unit for the EVM parameters can be changed in advance using UNIT EVM on page 275 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 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 12 Parameters lt Limit gt numeric value in dB The unit for the EVM parameters can be changed in advance using UNIT EVM on page 275 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 det
295. mmand This command is always used as a query so that you immediately obtain the name of the new window as a result Parameters Direction LEFT RIGHt ABOVe BELow lt WindowType gt Type of measurement window you want to add See LAYout ADD WINDow on page 246 for a list of availa ble window types Return values lt NewWindowName gt When adding a new window the command returns its name by default the same as its number as a result Example LAY WIND1 ADD LEFT MTAB Result 2 Adds a new window named 2 with a marker table to the left of window 1 Usage Query only LAYout WINDow lt n gt IDENtify This command queries the name of a particular display window indicated by the lt n gt suffix in the active measurement channel Note to query the index of a particular window use the LAYout IDENtifyl 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 Configuring the Result Display LAYout WINDow lt n gt REMove This command removes the window specified by the suffix lt n gt from the display in the active measurement channel The result of this command is identical to the LAYout REMove NINDow 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 i
296. mmand 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 on page 140 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 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance 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 on page 140 11 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 cha
297. mmands are required to configure the WLAN IQ measurement descri bed in chapter 3 1 WLAN UO Measurement Modulation Accuracy Flatness and Tol erance on page 12 SONA DESPO E 191 e Configuring the Data Input and Output eese 193 e Frontend Configuration oisi r 195 E E Mie Ir Le DEE 201 e Synchronization and OFDM Demodulaton eese 213 e Tracking and Channel ESHWmaetlIm set dice enr id den ten 214 LEER nil m 217 e Evaluation Neel E 230 LN Ug cc P el ere ite eel es sade aa ae 237 e AUtOMAtiO SOUNDS oia eds 240 e Configuring the Application Data Range MSRA mode only 240 11 5 1 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 195 Remote commands exclusive to describing the WLAN signal CONFIE STANG o Em 191 CAL CURIE LIMITOLSANCO iia 192 CONFigure STANdard lt Standard gt 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 Parameters lt Standard gt Manual operation 0 IEEE 802 11a 1 IEEE 802 11b 2 IEEE 802 11j 10 MHz 3 IEEE 802 11j 20 MHz 4
298. n 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 221 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Off Normalization step is omitted Remote command CONFigure WLAN SMAPping NORMalise on page 221 User Defined Spatial Mapping 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 221 CONFigure WLAN SMAPping TX ch STReam stream on page 222 CONFigure WLAN SMAPping TX ch TIMeshift on page 222 5 3 10 Evaluation Range The evaluation range defines which objects the result displays are based on The avail able settings depend on the selected standard e Evaluation Range Se
299. n 2 Qu 2 In so Qu Ns 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 11 4 Q4 4 I1 2 Q1 2 Uh ve Q1 Nsp OFDM Symbol 2 121 Q21 122 Q2 l2 uso Q2 Nsp OFDM Symbol N Uu Qn 1 In 2 Qu2 IN Nsp Qu nen 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 E 1 2 um Nusea 1 2 JL Nused 1 2 OFDM Symbol 1 l4 4 Q4 4 OFDM Symbol 2 24 Qz 1 OFDM Symbol N ly 4 Qn 1 11 9 4 7 11 9 4 8 11 9 4 9 11 9 4 10 Retrieving Results 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 Nuseq subcarri ers per OFDM Symbol until all the and Q data for the analyzed OFDM Symbols is exhausted 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 l 4 Q4 4 l4 2 Q1 2 Fi Nused gt Q1 Nusea OFDM Symbol 2 I 4 Qz 4 I22 Q2 2 12 Nuse Q2Nused OFDM Symbol N Ina Qu 4
300. n ee T Carrier 25 Carr Carrier Carrier 25 Carr Carrier Carner 25 Carr Carrier Carner rr Carrier 2 9 Stream 3 Rx 1 2 10 Stream 3 Rx 2 2 11 Stream 3 Rx 3 ABS Upper ABS Lomas EE a il aa aas er ee ee Carrier 25 Carr Carrier Carrer 25 Carr Carrier 2 16 Stream 4 Rx 4 ABS Upper Carrier 25 Carr Carrier Carrier 25 Carr Carrier 2 13 Stream 4 Rx 1 2 14 Stream 4 Rx 2 2 15 Stream 4 Rx 3 i nS ABS Lower A nee ene ees ee ee BEEN ae mun ep T e Carrier Carrier 25 Carr Carrier Carrier 25 Carr Carrier Carrier 25 Carr Carrier Carrier 25 Carr Fig 3 28 Spectrum flatness result display for IEEE 802 11n MIMO measurements The numeric trace results for this evaluation method are described in on page 297 Remote command LAY ADD 1 RIGH SFL see on page 246 or CONF BURS SPEC FLAT SEL FLAT see on page 188 and on page 189 Querying results see on page 297 50 R amp S FPS K91 Measurements and Result Displays 3 2 Frequency Sweep Measurements 3 2 1 As described above the WLAN IQ measurement captures the UO 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 sev
301. n the active measurement channel The result of this command is identical to the LAYout REPLace WINDow com mand To add a new window use the LAYout 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 246 for a list of availa ble window types 11 7 3 Selecting Items to Display in Result Summary The following command defines which items are displayed in the Result Summary 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 43 and Result Summary Global on page 44 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 11 8 Parameters for the items of the Result Summary Detailed Result in table SCPI parameter TX channel Tx All TALL UO offset IOFSset R amp S FPS K91 Remote Commands for WLAN Measurements Result in table SCPI parameter Gain imbalance GIMBalance Quadrature offset QOFFset PPDU power TPPower Crest factor TCFactor Receive channel Rx Al
302. nalField 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 46 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 Demodulation Parameters Logical Filters on page 80 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 Demodulation Parameters Logical Filters Example The evaluation range is configured to take the Source of Payload Length from the signal field If the power period detecte
303. name and index of all active windows in the active measurement channel 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 246 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 Compared to the DISPlay WINDow lt n gt SIZE on page 245 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 R amp S FPS K91 Remote Commands for WLAN Measurements 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 11 1 SmartGrid coordinates for remote control of the splitters Parameters lt Index1 gt The index of one window the splitter controls Index2 The index of a window on the other side of the splitter Position New vertical or horizontal position of the splitter as a fraction of the screen area without channel and status bar and
304. nderstood 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 position 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
305. ndividually 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 218 CONFigure WLAN GTIMe AUTO TYPE on page 219 CONFigure WLAN GTIMe SELect on page 220 5 3 9 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 Mapping Spatial Mapping Mode Spatial Expansion Power Normalise User Defined Spatial Mapping STS 1 STS 2 STS 3 STS 4 Nat Geen Spatal Mapping Mod ecne 137 Power INOMMALIS A ic red 137 User Defined EE ENEE ME 138 Spatial Mapping Mode Defines the mapping between streams and antennas For details see chapter 4 3 2 Spatial Mapping on page 72 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 Expansio
306. ne end ei e dern 81 OUMU m 81 A M 12 Payload Channel estimation sssssssssssss 121 215 Length noe nes 140 142 231 Length source remote sssesessesssss 231 Length SOUFCOS EE 140 WING OW escitas ias 59 Peak list Evaluation method teint ee tct tc 56 Peak vector error Measurement range erinnern 142 Peak Vector Error des Phase drift rere e rre te merus Tracking tee tet eren rers Tracking IEEE 802 11a g OFDM j p 61 Phase Error vs Preamble Result displays d Phase tracking EEN Phase Tracking Result displays eret mene ere enti 37 al lege e WEE 12 Pilots Le gue Lee ME 122 216 Polynomial degree A E 145 Power Interval search EE vs frequency vsime See PVT oie eet 39 40 41 Power interval search oooooccccconocococncocononononncnnccnnanonanonnno 214 Power normalize MIN tH eerte terit retten ee 137 PPDU el ele Lee ET 65 Amount to analyze 140 141 233 Amount to analyze remote esses 232 Analysis mode cus 124 127 133 Analyzed EE 10 79 Channel bandwidth 124 125 127 128 131 133 134 Count remote EE Currently analyzed e BDemodulatior retener mette tens Displayed ss trente eee rete EVM Direct 1 ihe te nen Extension Spatial Streams IEEE 802 11 n 135 218 Fortm t ices cece we 124 127 131 1
307. neration 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 122 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 generates more accurate mea surement results 10 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 FPS 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
308. ness and Tolerance 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 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 n DATA on page 284 All evaluations available for the selected WLAN measurement are displayed in Smart Grid mode To activate SmartGrid mode do one of the following E 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 91 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 MIMO measurements o 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 70 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 t
309. ng corrente trenes 57 IEEE 802 11a g OFDM j p ul 64 Modulation formats rrr trennt 80 IEEE 802 11g OFDM Signal proGesslhg eret rti teretes 57 IEEE 802 11n Modulation format siii ita 80 IF Power Trigger level remote eterne 205 Impedance Remote Setting Importing A 96 157 158 317 1Q data remote u c ies 297 ec corr ticos 157 Input Coublilig rro entertain erae Coupling remote o Coupling default Die P e ET Signal parameters Source Configuration softkey we 96 Source Radio frequency RF vu 96 Input sample rate 106 Default 2492 Displayed x reete ener herr rens 10 iod 203 Input sample rate ISR DENION Gosarian aaa aies 313 Installation uma iii 8 Inter channel interference ICI sess 59 IP address OSP switchbox MIMO AE 116 J Joined RX Sync and Tracking liec 115 K Keys BW A LINES use MKR FUNCT RUN CONT RUN SINGLE SPAN seis eidemque etes EE cia uae ES L Level Tracking Sisa aa desc iv veter em fs Tracking IEEE 802 11a g OFDM j p Level error tracking tete Limits Defining remote AAA 237 EVM pecc EVM pilot carriers result xs EVM result zinc ibant aia Freqeuncy error result i rotas Frequency
310. ng data Parameters lt SignalPath gt Example RX1 RX2 RX3 RX4 RX5 RX6 RX7 RX8 For details see Manual Sequential MIMO Data Capture on page 117 RST RX1 CONFigure WLAN MIMO CAPTure BUFFer RX2 Starts capturing data from the receive antenna number 2 CONFigure WLAN MIMO CAPTure TYPE Method Specifies the method used to analyze MIMO signals Parameters Method Manual operation SIMultaneous OSP MANual SIMultaneous Simultaneous normal MIMO operation OSP Sequential using open switch platform MANual Sequential using manual operation RST SIM See MIMO Antenna Signal Capture Setup on page 114 See Manual Sequential MIMO Data Capture on page 117 CONFigure WLAN MIMO OSP ADDRess Address 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Address gt Manual operation See OSP IP Address on page 116 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 Configur
311. nging 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 11 9 1 3 Limit Check Results on page 275 Useful commands for defining limits described elsewhere e UNIT EVM on page 275 e UNIT GIMBalance on page 275 Remote commands exclusive to defining limits CALGulate LIMIEBU RSEGALL iiiter aate ara A cya aa ase i cya ERR Tri se Xa aC ave a 237 CALOCulate LIMit BURSt EVM ALL AVERage eese 238 CALCulate LIMit BURSt EVM ALL MAXiIMUM 0cccccsececesssceceeccceseeeesesseeeceaeeeecnseesensees 238 CAL CulateL IMC BURGCEVM DATA AVERaoel anna nnnnnnnn 238 CAL Culate LIMit BURSt EVM DATA MAXiMUM cocoocccccooccnccconnccnonnnnonnnononnncnonnnnnnnnnnnnnnnnnnnos 238 CALOCulate LIMit BURStEVM PILot AVERage seen 238 GALCulatecLIMIEBBURStEVM PIEOGEMAXIIUETI ird acictu cuota dd 238 CALCulate LIMIt BURSCEFERRor AVERage 2 2 mae deca tet ott eee ent aen 239 GCALOCulate LIMIEBURStFERRorMAXimUum 2 en enne naeh snas nnn k nsa RR eaae 4a EENS 239 CALCulate LIMit BURSt IQOFfset AVERage essere 239 CAL Culate LIMIt BURSEIQOFfSet MAXIMUM e aea aiaia aoa a aE 239 CAL CulateL IM BURGt SvMolerortAVEHRagel nana 239 CAL Culate IM BURGt SvMolerror MA ximum 239 CALCulate LIMit BURSt ALL Limits This command sets or returns the
312. nitude value has to be multiplied For multi channel signals the ScalingFactor must be applied to all channels The attribute unit must be set to v The ScalingFactor must be gt 0 If the ScalingFactor element is not defined a value of 1 V is assumed NumberOfChan Optional specifies the number of channels e g of a MIMO signal contained in the nels 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 320 If the NumberOfChannels element is not defined one channel is assumed 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 xyz a valid Windows file name e Format complex polar or real see Format element e Channels Number of channels see NumberOfChannels element e Type float32 float64 int8 int16 int32 or int64 see DataType element Examples e xyz complex 1ch float32 e xyz polar 1ch float64 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
313. nly 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 Parameters State 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 120 11 5 6 Tracking and Channel Estimation SENSE DEMO CES TIMO cuchara ede eee xe teo ete elato eaten ed 215 SENSe TRAGCKing CROSStalk 2 2 22 2 iaa EE 215 SENSE Ge leie Be Tt 215 SENSeTTRAGCkingiEEVel 5 2 NEEN AER ada dida 216 SENSE TRACKING RE 216 SENSeJ TRAC iO PILONS aida 216 BENSe TRACKIng TIME 1 2 rentre treten terns rk etd be a nba 217 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance SENSe DEMod CESTimation lt State gt 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 Para
314. noneninonansncnan ca racaracncnnencaneconoss 254 DISPlay WINDow lt n gt TRACe lt t gt X SCALe AUTO FlXed RANGe 255 DISPlay WINDow N TRACez t X SCALe AUTO HYSTeresis LOWer LOWer esess 256 DISPlay WINDow lt N gt TRACe lt t gt X SCALe AUTO HYSTeresis LOWerUPPeF cococciccccconocccccnonccnonencnnnnns 255 DISPlay WINDow N TRACez t X SCALe AUTO HYSTeresis UPPer LOWer esee 256 DISPlay WINDow lt N gt TRACe lt t gt X SCALe AUTO HYSTeresis UPPer UPPE eeeeeeese 256 DISPlay WINDow n TRACe t X SCALe AUTO MEMory DEPTh essen 257 DISPlay WINDow n TRACe t X SCALe AUTO MODE essere nennen 257 DISPlay WINDow lt n gt TRACe lt t gt X SCALe DIVisions DISPlay WINDow n TRACe st X SCALe MAXimum sees 258 DISPlay WINDow n TRACe t X SCALe MINimum esee nennen 259 DISPlay WINDow n TRACe t X SCALe PDlVision esses 259 DISPlay WINDow n TRACe st Y SCALe AUTO essere rennen neret neret 254 DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO FlXed RANG6 oooccccccocococccconononncnononanccnnanannc nana nan ccnnnos 255 DISPlay WINDow N TRACe t Y SCALe AUTO HYSTeresis LOWer LOWer esees 256 DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis LOWerUPPeTF coocociccccconoc
315. nput 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 121 The channel estimation is performed in the preamble and the payload The EVM results can be calculated more accurately R amp S FPS 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 122 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 122 Compensating for non standard conform pilot sequences In case the pilot ge
316. nsion option see chapter A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input on page 313 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 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 4
317. nsmitted power If this command is set to OFF the normalization step is omitted Parameters State Manual operation See Power Normalise on page 137 CONFigure WLAN SMAPping TX lt ch gt lt 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 16 9 Manual operation See User Defined Spatial Mapping on page 138 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 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 138 CONFigure WLAN SMAPping TX ch TIMeshift lt TimeShift gt This remote control command specifies the ti
318. nt with 2 receive antennas Note that additionally the data contents of the sent PPDU 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 Calculating Results When you analyze a WLAN signal in a MIMO setup the R amp S FPS 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 Receive Stream Stream Antenna Antennas Signals Signals Signals p Precoding I d Space Time s EN H e s R Here y Block Code Ma ae ES Hphy Qs STBC pping y X Hor S ed mI internal cross talk Channel Flatness Group Delay Physical Channel Hpny r F Channel Flatness M Group Delay Effective Channel Hert Hpny Q i i EVMss EVMsrs 1 Q Offset Burst Power Conventional EVM Conventional EVM Gain Imbal
319. nterval of 2 symbols for the estimation of H S leads to a nearly error free channel estimate In the following equalizer block ALS 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 HL from the payload for equalization If the improved esti mate AUS 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 HS from the long symbol has to be used for equalization Therefore the default setting of the R amp S FPS WLAN application is equalization from the coarse channel esti mate 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 1 nof packets EVM 3 EVM counter nof packets counter 1 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 Y EVM k 26 kz0 Error vector magnitude of the entire packet 4 7 Finally the average error vector magnitude is calculated by averaging the packet EVM of all n
320. nual 1176 8551 02 06 446 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Automatic Gfid ScdlifIgi cortes aged ctae zer rte year aid XR dn 147 AWO MOJE EE 147 PUTO TRUK FREI GS id 147 Hysteresis Interval Upper LOWS nesimi telle a A Aaa 148 Minimum Maximini EE 148 Memory DOU e P 148 Number E Ee EE 149 Scaling per GIVISION RE 149 Automatic Grid Scaling Activates or deactivates automatic scaling of the x axis or y axis for the specified trace display If enabled the R amp S FSW WLAN application automatically scales the x axis or y axis to best fit the measurement results If disabled the x axis or y axis is scaled according to the specified Minimum Maxi mum and Number of Divisions Remote command DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO on page 254 Auto Mode Determines which algorithm is used to determine whether the x axis or y axis requires automatic rescaling Hysteresis If the minimum and or maximum values of the current measurement exceed a specific value range hysteresis interval the axis is rescaled The hysteresis interval is defined as a percentage of the currently displayed value range on the x axis or y axis An upper hys teresis interval is defined for the maximum value a lower hysteresis interval is defined for the minimum value See Hysteresis Interval Upper Lower Memory
321. nual inter action is necessary during the measurement The R amp S FSW WLAN application captures the UO 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 S OSP 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 75 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 Se
322. nual operation The spectrum emission mask measurement is performed according to the standard Parameter value IEEE 802 11mb D08 20M 2 4G IEEE Std 802 11n 2009 Figure 20 17 Transmit spectral mask for 20 EEE D08 20 2 4 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 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 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 Figure 19 20 Transmit spectral mask for a 40 MHz channel in the 5 GHz band IEEE 802 11ac D1 1 20M 9 5G IEEE P802 11ac D1 1 August 2011 Figure 22 17 Transmit spectral mask for a 20 MHz channel EEE AC D1 1 20 5 IEEE 802 11ac D1 1 40M 5G IEEE P802 11ac D1 1 August 2011 Figure 22 18 Transmit spectral mask for a 40 MHz channel EEE AC D1 1 40 5 IEEE 802 11ac D1 1 80M 5G IEEE P802 11ac D1 1 August 2011 Figure 22 19 Transmit spectral mask for a 80 MHz channel IEEE AC D1 1 80 5
323. o 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 193 Impedance The reference impedance for the measured levels of the R amp S FPS can be set to 50 O or 75 0 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 Q in series to the input impedance of the instrument The correction value in this case is 1 76 dB 10 log 750 500 Remote command INPut IMPedance on page 194 YIG Preselector Activates or deactivates the YIG preselector if available on the R amp S FPS WLAN IQ Measurement Modulation Accuracy Flatness Tolerance An internal YIG preselector at the input of the R amp S FPS ensures that image frequen cies are rejected However the YIG filter may limit the bandwidth of the I Q 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 193 5 3 4 2 Output Settin
324. of symbols detected packets 1 nof symbols 2 EVM 2 ra 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 802 112 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 processing concept of the WLAN 802 11 application for IEEE 802 11b or g DSSS signals A
325. on such as a USB memory device For details see Protecting Data Using the Secure User Mode in the Data Manage ment section of the R amp S FPS User Manual Remote command MMEMor y STORe lt n gt TQ STATe on page 298 How to Export and Import I Q Data UO data can only be exported in applications that process l Q data such as the UO Analyzer or optional applications Capturing and exporting I Q 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 a 5 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 IO Import softkey Select the storage location and the file name with the iq tar file extension o oco B Y Ww Select Open The stored data is loaded from the file and displayed in the current application Previewing the I Q data in a web browser The ig t
326. onization Using the Master s Trigger Output on page 86 Remote command OUTPut TRIGger lt port gt LEVel on page 208 OUTPut TRIGger port DIRection on page 208 Output Type Trigger 2 Type of signal to be sent to the output Device Trig Default Sends a trigger when the R amp S FPS triggers gered Trigger Sends a high level trigger when the R amp S FPS is in Ready for trig Armed ger state This state is indicated by a status bit in the STATus OPERation reg ister bit 5 5 3 5 3 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance 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 209 Level Output Type Trigger 2 Defines whether a constant high 1 or low 0 signal is sent to the output connector Remote command OUTPut TRIGger lt port gt LEVel on page 208 Pulse Length Output Type Trigger 2 Defines the length of the pulse sent as a trigger to the output connector Remote command OUTPut TRIGger lt port gt PULSe LENGth on page 209 Send Trigger Output Type Trigger 2 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 o
327. ons within a single PPDU If activated the measurement results are compensated for level error on a per symbol basis Parameters lt State gt ON OFF RST OFF Manual operation See Level Error Gain Tracking on page 122 SENSe TRACking PHASe lt State gt 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 lt State gt ON OFF 0 1 RST 1 Example SENS TRAC PHAS ON Manual operation See Phase Tracking on page 122 SENSe TRACking PlLots Mode In case tracking is used the used pilot sequence has an effect on the measurement results Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Mode gt STANdard 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 p
328. or details see chapter 3 1 1 4 1 Q Skew on page 18 Usage Query only FETCh BURSt MCPower AVERage FETCh BURSt MCPower MAXimum FETCh BURSt MCPower MINimum This command returns the MIMO cross power average maximum or minimum value in dB for the IEEE 802 11n MIMO standard For details see chapter 3 1 1 Modula tion Accuracy Flatness and Tolerance Parameters on page 12 Parameters Result Stream 1 result Stream n result FETCh BURSt PAYLoad AVERage FETCh BURSt PAYLoad MINimum FETCh BURSt 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
329. otherwise an error will occur A detailed programming example is provided in the Operating Modes chapter in the R amp S FPS User Manual Parameters lt State gt 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 90 11 9 Retrieving Results The following commands are required to retrieve the results from a WLAN measure ment in a remote environment Retrieving Results Before retrieving measurement results check if PPDU synchronization was successful or not by checking the status register see chapter 11 11 1 The STATus QUEStiona ble SYNC Register on page 302 If no PPDUs were found STAT QUES SYNC COND returns O see STATus QUEStionable SYNC CONDition on page 304 11 9 1 11 9 1 1 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 e Numer
330. ou use the manual mode initially to get familiar with the instru ment and its functions before using it in pure remote mode Thus this document describes in detail how to operate the instrument manually using an external monitor and mouse The remote commands are described in the second part of the document For details on manual operation see the R amp S FPS Getting Started manual To activate the WLAN application 1 Select the MODE key A dialog box opens that contains all operating modes and applications currently available on your R amp S FPS 2 Select the WLAN item A o WLAN The R amp S FPS 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 93 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 R amp S FPS K91 Welcome to the WLAN Application MultiView 22 Spectrum WLAN Sampling Rate Fs 320 0 MHz Standard X aC Capt Time No of Samples 5m PPDU MCS Index GI Meas Setup 1 Tx Rx No of Data Symbols SGL Analyzed PPDUs 1 Magnitude Capture 2 I Clow 6 Spectrum Fatness 1 Avg 2 Cirw 3Result Summary Global
331. page 151 SENSe MSRA CAPTure OFFSet Offset This setting is only available for applications in MSRA mode not for the MSRA Master It has a similar effect as the trigger offset in other measurements Parameters Offset This parameter defines the time offset between the capture buf fer start and the start of the extracted application data The off set must be a positive value as the application can only analyze data that is contained in the capture buffer Range O to Record length RST 0 Manual operation See Capture Offset on page 106 Configuring Frequency Sweep Measurements on WLAN Signals The R amp S FPS WLAN application uses the functionality of the R amp S FPS base system Spectrum application see the R amp S FPS User Manual to perform the WLAN fre quency sweep measurements The R amp S FPS WLAN application automatically sets the parameters to predefined settings as described in chapter 5 4 Frequency Sweep Measurements on page 151 Configuring Frequency Sweep Measurements on WLAN Signals The WLAN RF measurements must be activated for a measurement channel in the WLAN application see chapter 11 3 Activating WLAN Measurements on page 180 For details on configuring these RF measurements in a remote environment see the Remote Commands chapter of the R amp S FPS User Manual Remote commands exclusive to SEM measurements in the WLAN application E Ee activator eda EXER EA 243 ISENSeTPOWer SEM CE
332. quential MIMO Measurement on page 75 Single antenna measurement The data from the Tx antenna is measured 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 74 User Manual 1176 8551 02 06 75 Rx1 Capture Memory Rx2 Capture Memory Signal Processing for MIMO Measurements IEEE 802 11ac n In addition the following PPDU attributes must be identical for ALL antennas e PPDU length e PPDU type 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 a KH Tat cis same PPDU attributes kt ay di PPDU attribut different PPDU contents Le e PPDU simu Vi a a VON NW X ci A Ae Ges See at 4 3 5 Fig 4 5 Basic principle of Sequential MIMO Measureme
333. r details see chapter 4 9 6 Trigger Synchronization Using an R amp S FS Z11 Trigger Unit on page 86 Remote command TRIGger SEQuence SOURce on page 207 Capture Offset Trigger Source Settings This setting is only available for applications in MSRA operating mode It has a similar effect as the trigger offset in other measurements it defines the time offset between the capture buffer start and the start of the extracted application data In MSRA mode the offset must be a positive value as the capture buffer starts at the trigger time 0 Remote command SENSe MSRA CAPTure OFFSet on page 242 Trigger 2 Defines the usage of the variable TRIGGER AUX 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 FPS User Manual Input The signal at the connector is used as an external trigger source by the R amp S FPS No further trigger parameters are available for the con nector Output The R amp S FPS sends a trigger signal to the output connector to be used by connected devices Further trigger parameters are available for the connector Note For simultaneous MIMO measurements see Simultaneous Signal Capture Setup on page 114 if you set the master s TRIGGER 2 INPUT OUTPUT connector to device triggered output the master R amp S FPS sends its trigger event signal to any connected slaves See also chapter 4 9 5 Trigger Synchr
334. r 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 128 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 229 Parameters Index Example SENS DEM FORM NSTS MODE MEAS SENS DEM FORM NSTS 1 Manual operation See Nsts on page 129 SENSe DEMod FORMat NSTSindex MODE lt Mode 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 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
335. r lt m gt Y This command queries the position of a marker on the y axis If necessary the command activates the marker first To get a valid result you have to perform a complete measurement with synchroniza tion to the end of the measurement before reading out the result This is only possible for single measurement mode See also INITiate lt n gt CONTinuous on page 261 Return values lt Result gt Result at the marker position Example INIT CONT OFF Switches to single measurement mode CALC MARK2 ON Switches marker 2 INIT WAI Starts a measurement and waits for the end CALC MARK2 Y Outputs the measured value of marker 2 Usage Query only Manual operation See CCDF on page 54 See Marker Table on page 55 See Marker Peak List on page 56 R amp S FPS K91 Remote Commands for WLAN Measurements 11 10 2 Zooming into the Display 11 10 2 1 Using the Single Zoom RIIT WINDOW 0 gt ZO OMAR EE 300 DISPIay WINDowsrs p ZOONM ISTATO6 uaa cccu rta dE rtp eure Li panne cutn 300 DISPlay 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 MU CF 2 000519931 GHz 498 pts 1 24 MHz Span 12 435008666 MHz 1 origin of coordinate system x1 0 y1 0 2 end point of system x2 100 y2 100 3 zoom area e g x1 60 y1 30 x2 80 y2 75 Parameters lt
336. rance Parameters for WEAN SINS iia AAA 161 How to Determine the OBW SEM ACLR or CCDF for WLAN Signals 163 How to Determine Modulation Accuracy Flatness and Tolerance Parameters for WLAN Signals 10 Press the MODE key A dialog box opens that contains all operating modes and applications currently available on your R amp S FPS Select the WLAN item WLA The R amp S FPS 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 define the digital standard to be used Select the Input Frontend button and then the Frequency tab to define the input signal s center frequency Select the Signal Capture button to define how much and which data to capture from the input signal 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 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 Evaluation Range button to define which data in the capture buffer you want to analyze How to Determine Modula
337. range Analysis line A frequent question when analyzing multi standard signals is how each data channel is correlated in time to others Thus an analysis line has been introduced The analysis line is a common time marker for all MSRA applications It can be positioned in any MSRA application or the MSRA Master and is then adjusted in all other applications Thus you can easily analyze the results at a specific time in the measurement in all applications and determine correlations If the marked point in time is contained in the analysis interval of the application the line is indicated in all time based result displays such as time symbol slot or bit dia grams By default the analysis line is displayed however it can be hidden from view manually In all result displays the AL label in the window title bar indicates whether or not the analysis line lies within the analysis interval or not orange AL the line lies within the interval e white AL the line lies within the interval but is not displayed hidden e no AL the line lies outside the interval The analysis line is displayed in the following result displays e Magnitude Capture Power vs Time e EVM vs Symbol For details on the MSRA operating mode see the R amp S FPS MSRA User Manual User Manual 1176 8551 02 06 88 Multiple Measurement Channels and Sequencer Function 9 Configuration 5 1 The default WLAN UO measurement captures the UO data fro
338. range Example CALC MARK2 X 1 7MHz Positions marker 2 to frequency 1 7 MHz Manual operation See Marker Table on page 55 See Marker Peak List on page 56 CALCulate lt n gt STATistics RESult lt t gt lt ResultType gt This command queries the results of a CCDF or ADP measurement for a specific trace lt n gt is irrelevant 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 power 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 54 Retrieving Results 11 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 1
339. re beg tee netto etd 270 el Ke RE E ge EE 272 FETCh BURSCECFERTrOr MAXIMUM raene aena ip aseo 272 FETCH BURSECFERTOR MINIMUM seyis Ad ad 272 FETGCMBURSECOUNCAL EE 266 FETCh BURSECOUNE cist EA ESSEN 266 FETCh BURSt CPERror AVERage FETCHN BURSECPERTOE MAX MUNI 270 FETCh BURSECPERTFOr MINIMUM escisiones Eeee SKEET EE iaa as 270 FETCICB RSEORESEMAXImUITI ege creer Ponte Bb edente ete trente t dta Y ried 270 FETCN BURSECRESEMINIMUN 3 cat Hoe EECH 270 FETCh BURSECRESIAVERage nnt euer tit tese oo ini ae EENEG 270 FETCICBURSCEVM ALLPAVERGQO tti teet rte tte bre eed eerte tp e oae 271 FETCHN BURSEEVM ALE A VERO toscanini od 273 FETCh BURSEEVM AUL MAXIMUD EE 271 FETCH BURStEVMIALL MAXIMUIN Li A ee 273 FETCh BURSEEVM AELMINIIUTTI cocos s Nee 271 FETCh BURSt EVM ALL MINimum FETCHBURStEVM DATA A VERDS incar eer erre ere acer een per ere ye ha e Rev re arae 271 FETOCHBURGSCEVMDATAMANImum nennen ennt enne nnns snnt r enne n nre Eain 271 FETCH BURSCcEVM DATA MINIMUM ost er crane ever rtp etn entr p etti pee nee edet 271 FETGh B RSEEVM DIReCEAVERAGQS intuere eorr eee decr e D ce E FER EYE ER 271 FETCH BURSHEVM DIRGCE MAXIMUM iisscssasesestcescesceacsceeus rero coxccaiaeasusnrsctneonevgueatacs ERE RASERER Ea Ena 271 FETCHh BURSEEVMEDIR6GGEMINIFOUET scc rrt eee Rt a ette Ea ee NY 271 FETCh BURSt EVM PlLot AVERage sa FETCh BURStE
340. 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 define 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 comp
341. rement Basics application data For the R amp S FSW WLAN application in MSRA operating mode the application data range is defined by the same settings used to define the signal cap ture in Signal and Spectrum Analyzer mode In addition a capture offset can be defined i e an offset from the start of the captured data to the start of the analysis interval for the WLAN l Q measurement Data coverage for each active application Generally if a signal contains multiple data channels for multiple standards separate applications are used to analyze each data channel Thus it is of interest to know which application is analyzing which data channel The MSRA Master display indicates the data covered by each application restricted to the channel bandwidth used by the corresponding standard by vertical blue lines labeled with the application name Analysis interval However the individual result displays of the application need not analyze the com plete data range The data range that is actually analyzed by the individual result dis play is referred to as the analysis interval In the R amp S FSW WLAN application the analysis interval is automatically determined according to the selected channel carrier or PPDU to analyze which is defined for the evaluation range depending on the result display The analysis interval can not be edi ted directly in the R amp S FSW WLAN application but is changed automatically when you change the evaluation
342. rement is executed e g using the INTTiate lt n gt 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 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 11 7 2 Working with Windows in the Dis play on page 246 Results are only displayed after a measurement is executed e g using the INITiate lt n gt 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 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 n IMMediate command Usage Event Manual operation See EVM vs Chip on page 30 See EVM vs Symbol on page 30 CONFigure BURSt GAIN GCARrier IMMediate This remote control command configures the result display type of window 2 to be Gain Imbalance vs Carrier Results are only displayed after a measurement is executed e g usin
343. results to be considered when determining if rescaling is required The minimum and maximum value of each measurement are added to the memory After lt x gt measurements the oldest results in the memory are overwritten by each new measurement For details see Auto Mode on page 147 Parameters lt NoMeas gt integer value Number of measurement results to be stored for autoscaling Example DISP WIND2 TRAC Y AUTO MEM DEPT 16 Manual operation See Memory Depth on page 148 DISPlay WINDow lt n gt TRACe lt t gt X SCALe AUTO MODE lt AutoMode gt DISPlay WINDow lt n gt TRACe lt t gt Y SCALe AUTO MODE lt AutoMode gt This command determines which algorithm is used to determine whether the x axis or y axis requires automatic rescaling Configuring the Result Display Parameters lt AutoMode gt HYSTeresis If the minimum and or maximum values of the current measure ment exceed a specific value range hysteresis interval the axis is rescaled The hysteresis interval is defined as a percentage of the currently displayed value range on the x axis or y axis An upper hysteresis interval is defined for the maximum value a lower hysteresis interval is defined for the minimum value MEMory If the minimum and or maximum values of the current measure ment exceed the minimum and or maximum of the lt x gt previous results the axis is rescaled The minimum and maximum value of each measurement are added to t
344. rier 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 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 51 See Occupied Bandwidth on page 53 CALCulate lt n gt MARKer lt m gt X Position This command moves a marker to a particular coordinate on the x axis If necessary the command activates the marker If the marker has been used as a delta marker the command turns it into a normal marker Parameters Position Numeric value that defines the marker position on the x axis Range The range depends on the current x axis
345. rieving Results Example For GD n the group delay of the m th analyzed PPDU for the subcarrier correspond ing to n 1 2 Nusea Y TRACE DATA TRACE2 Analyzed PPDU 1 GD GD 2 xy Analyzed PPDU 2 GD 1 GD xu Analyzed PPDU N GDy 1 GDy isi Magnitude Capture Returns the magnitude for each measurement point as measured over the complete capture period The number of measurement points depends on the input sample rate and the capture time see chapter 5 3 5 Signal Capture Data Acquisition on page 105 Phase Tracking Returns the average phase tracking result per symbol in Radians These results are not available for single carrier measurements IEEE 802 11b g DSSS 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 relates 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 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 Suppo
346. rt position of each analyzed PPDU in the current capture buffer Retrieving Results 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 266 Parameters Unit SYMBol SAMPle RST SYMBol 11 9 1 2 Error Parameter Results The following commands are required to retrieve individual results from the WLAN IQ measurement on the captured UO data see chapter 3 1 1 Modulation Accuracy Flat ness and Tolerance Parameters on page 12 PW Ci WR EE 269 FETOCHRBURGSCAM AM CGOEFioente 270 FETCH BURSUBERPIOUAV e 270 FETCH BURSEBERPIOE MAXIMA ociosa aaa Pd sabes 270 Ree CAT E ere Ode RE 270 EIERE REENEN 270 al Rer Ee ele ln TEE 270 FETCHBURSECPERrO MINIMUM DEE 270 IS el ue E RN E KEE 270 FET CHBURSECRESE MAXIMUM RE 270 FETCH BURSECRESEMINIMUN Lacio adria 270 FETCHIBURSEEVMIABE AVERAGQGT ii ti a 271 FETGMBURSCEVM ALL MAXIMU EE 271 FETCh BURSEEVMEAEEMIBNIABINQN aiii iii iere cita erre ceo te pre eda ga EEN 271 FETGIL BURSEEVMIDATALAV ERGO iru eoi tr oct Re E eet ebe a ERU REIR EE 271 FETOCHRBURGSGEVMDATAMAXimum nennen nnne mense see sese se sense sensn 271 GER Red ERR All E RE 271 FETCHBURSEEVMDIRectAVERage ion ibas 271 FETGHIBURSEEVM DIRSCEMJAXITITI ciciecvedesisecea
347. rted data formats see FORMat DATA on page 283 ASCii REAL Retrieving Results 11 9 4 18 Signal Field The bits are returned as read from the corresponding signal field parts in transmit order l e the first transmitted bit has the highest significance and the last transmitted bit has the lowest significance See also Signal Field on page 46 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 11 9 4 19 Spectrum Flatness The spectrum flatness evaluation returns absolute power values per carrier Two trace types are provided for this evaluation Table 11 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 results are returned in dB Supported data formats FORMat DATA ASCii REAL 11 9 5 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 d
348. rting point for application starting point in capture buf fer 5 The analysis interval is automatically determined according to the selected chan nel carrier or PPDU to analyze defined for the evaluation range depending on the result display Note that the channel carrier PPDU is analyzed within the appli cation data If the analysis interval does not yet show the required area of the cap ture buffer move through the channels carriers PPDUs in the evaluation range or correct the application data range 6 Ifthe Sequencer is off select the Refresh softkey in the Sweep menu to update the result displays for the changed application data How to Determine the OBW SEM ACLR or CCDF for WLAN Signals 8 2 How to Determine the OBW SEM ACLR or CCDF for WLAN Signals 1 Press the MODE key and select the WLAN application The R amp S FPS opens a new measurement channel for the WLAN application UO data acquisition is performed by default 2 Select the Signal Description button to define the digital standard to be used 3 Select the required measurement a Press the MEAS key b In the Select Measurement dialog box select the required measurement The selected measurement is activated with the default settings for WLAN immedi ately 4 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 subdire
349. s lt NewWindowName gt When adding a new window the command returns its name by default the same as its number as a result Example Usage Manual operation Configuring the Result Display LAY ADD 1 LEFT MTAB Result r2 Adds a new window named 2 with a marker table to the left of window 1 Query only See AM AM on page 22 See AM PM on page 23 See AM EVM on page 23 See Bitstream on page 24 See Constellation on page 26 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 33 See Gain Imbalance vs Carrier on page 33 See Group Delay on page 34 See Magnitude Capture on page 35 See Phase Error vs Preamble on page 37 See Phase Tracking on page 37 See PLCP Header IEEE 802 11b g DSSS on page 38 See PvT Full PPDU on page 39 See PvT Rising Edge on page 40 See PvT Falling Edge on page 41 See Quad Error vs Carrier on page 42 See Result Summary Detailed on page 43 See Result Summary Global on page 44 See Signal Field on page 46 See Spectrum Flatness on page 49 See Diagram on page 55 See Result Summary on page 55 See Marker Table on page 55 See Marker Peak List on page 56 Table 11 7 lt WindowType gt parameter values for WLAN application Parameter value Window type Window types for I
350. s these values are either detected auto matically from the signal or the user settings are applied E User Manual 1176 8551 02 06 10 Understanding the Display Information Label Description Standard 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 FPS 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 W
351. s 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 46 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 ve Demod allas All PPDUs are analyzed assuming the specified Ness value Ness lt x gt Remote command CONFigure WLAN EXTension AUTO TYPE on page 218 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 46 Auto same type as first PPDU A1st All PPDUs using the guard interval length identical to the first recog nized PPDU are analyzed Auto i
352. s see PvT Full PPDU on page 39 Remote command CONFigure BURSt PVT RPOWer on page 231 Peak Vector Error Meas Range 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance PSDU only Peak Vector Error results are calculated over the PSDU only Remote command CONFigure WLAN PVERror MRANge on page 232 5 3 11 Result Configuration For some result displays additional settings are available The Result Configuration softkey in the main WLAN menu opens the Result Con figuration dialog box This softkey is only available if a window with additional settings is currently selected Alternatively select a window from the Specifics for selection list in the Overview then select the Result Configuration button to display the Result Configuration dia log box Depending on the selected result display different settings are available e Result Summary Configuratlort 1 oio dte ence ciet ep Erb ore roug 143 e Spectrum Flatness and Group Delay Configuration esses 144 e AM AM Confouratton nennen nennen nen nnn ines 145 5 3 11 1 Result Summary Configuration You can configure which results are displayed in Result Summary displays see Result Summary Detailed on page 43 and Result Summary Global on pag
353. s the upper limit of the lower hysteresis interval Ifthe minimum value in the current measurement exceeds this limit the x axis or y axis is rescaled automatically For details see Hysteresis Interval Upper Lower on page 148 Parameters lt Value gt Percentage of the currently displayed value range on the x axis or y axis Example DISP WIND2 TRAC Y SCAL AUTO HYST LOW UPP 5 Manual operation See Hysteresis Interval Upper Lower on page 148 Configuring the Result Display DISPlay WINDow lt N gt TRACe lt t gt X SCALe AUTO HYSTeresis LOWer LOWer lt Value gt DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis LOWer LOWer lt Value gt For automatic scaling based on hysteresis this command defines the lower limit of the lower hysteresis interval Ifthe minimum value in the current measurement drops below this limit the x axis or y axis is rescaled automatically For details see Hysteresis Interval Upper Lower on page 148 Parameters lt Value gt Percentage of the currently displayed value range on the x axis or y axis Example DISP WIND2 TRAC Y SCAL AUTO HYST LOW LOW 5 Manual operation See Hysteresis Interval Upper Lower on page 148 DISPlay WINDow lt N gt TRACe lt t gt X SCALe AUTO HYSTeresis UPPer LOWer lt Value gt DISPlay WINDow lt N gt TRACe lt t gt Y SCALe AUTO HYSTeresis UPPer LOWer lt Value gt For automatic scaling based on hysteresis this command defines
354. s 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 135 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 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt State gt ON The guard time is detected automatically according to CONFigure WLAN GTIMe AUTO TYPE on page 219 OFF The guard time is defined by the CONFigure WLAN GTIMe SELect command RST ON Manual operation See Guard Interval Length on page 130 CONFigure WLAN GTIMe AUTO TYPE Type This remote control command specifies which PPDUs are analyzed depending on their guard length if automatic detection is used CONF WLAN GTIM AUTO ON see CONFigure WLAN GTIMe AUTO on page 218 This command is available for IEEE 802 11 n ac standards only Note On previous R amp S Signal and Spectrum analyzers this command configured both the guard interval type and the channel
355. see I Q Mismatch Compensa tion on page 122 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 802 11ac 2013 WLAN standard may not use compensation 3 1 1 6 3 1 1 7 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 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 dis abled 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 FPS WLAN application The IQ offset measurement in the R amp S FPS 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 The RF carrier suppression measured according to the standard is inversely propor tional to the IQ offset measured in the R amp S FPS WLAN applica
356. 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 FPS later e Capturing and saving l Q signals with an RF or baseband signal analyzer to ana lyze them with the R amp S FPS or an external software tool later As opposed to storing trace data which may be averaged or restricted to peak values 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 FPS l Q Analyzer and l Q Input User Manual Export only in MSRA mode In MSRA mode UO data can only be exported to other applications l Q data cannot be imported to the MSRA Master or any MSRA applications e Import Export FUheti fs eroe Seale rte eic PE de de eet ea 157 e Howto Export and Impott VO Data units a 158 Import Export Functions The following import and export functions are available via softkeys in the Save Recall menu which is displayed when you select the Save or
357. softkey menu The point of origin x 0 y 0 is in the lower left corner of the screen The end point x 100 y 100 is in the upper right cor ner of the screen See figure 11 1 The direction in which the splitter is moved depends on the screen layout If the windows are positioned horizontally the splitter also moves horizontally If the windows are positioned vertically the splitter also moves vertically Range 0 to 100 Example LAY SPL 1 3 50 Moves the splitter between window 1 Frequency Sweep and 3 Marker Table to the center 50 of the screen i e in the fig ure above to the left User Manual 1176 8551 02 06 250 Configuring the Result Display 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 n 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 WINDow lt n gt REPLace co
358. ssaaeneeserstavecsteas 275 FETCh BURSt TRISe MINimum 5275 FETGh SYMBOLGOLUNIE i erre er a eec ee e Er FOE PEE dice 266 FORMatliDATA E 283 INITiatesms CONTIDUOUS tite e ra rese cl c tpa ele eet 261 INI Tiatesns REFRE EE 242 INITiatesns SEQuencerABORLE nacioni oio rnnt coron tne oS EEP Es nara ENET E ARNEE NOAE 262 INI Tiate ns SEQuencerIMMediale 1 puce e ette rt reprae crece pce dv cx dert uds 262 INITiate lt n gt SEQuencer MODE T ll EE E UR EE 263 ll ME BITTEN 261 INPUEA T TS ERE Em 199 TN RENE SIE E TC CH 200 INPUECOU Olne 193 INPUT PAD m dad nat OM 193 INPut EATT n du ziuis Hess Eno X HM 200 INPUtEATT STAT6 s scontri ee crecer herr ea ee FEBRE Ce 201 INPUtRIE ee de HL E isre 193 INPUEGAIN XE 201 wb abuti M X X M MX 194 INRUESELSCE bear 194 INSTr ment er E RUE TE 180 INSTrument CREate REPLACE iss rper ctii ith c rece HM OR EE EUER E e a T Ee docu EE DN 181 INS Trument CRE Ate pande 180 INSTr ment BI E 181 Jee Tt ae BEE 181 NEEN ENEE EE 182 INSTr rment SEL6Gt ertt etr etie ere tem tn i a e e ERE LEER 183 LEAYOUEADDEWINDOW iria euer ere ra rer Rr rr
359. stic 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 WLAN UO Measurement Modulation Accuracy Flatness and Tolerance Parameter Peak vector error Description 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 20 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 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 16 Quadrature error Measure for the crosstalk of the Q branch into the
360. stics BSTReam IMMediate on page 189 Querying results TRACe lt n gt DATA see chapter 11 9 4 4 Bitstream on page 290 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 pum EIN RN QC NONI ANC NN M NU User Manual 1176 8551 02 06 26 R amp S FPS K91 Measurements and Result Displays 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 The numeric trace results for this evaluation method are described in on page 292 Remote command LAY ADD 1 RIGH CONS see on page 246 or on page 185 Querying results See on page 292 User Manual 1176 8551 02 06 27 R amp S FPS K91 Measurements and Result Displays 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
361. stimation gt Channel Estimation Channel Estimation Range Tracking Tracking for the signal to be measured Phase Timing IQ Mismatch Compensation Off Pilots for Tracking According to Standard t MIMO Compensate Crosstalk Channel Estimation Range 121 Phase Re e DEE 122 Timing Error Tracking a tiec ed eei cer ih cde eh cocer 122 Level Error Gain WE Te E 122 UO Mismatch Compensation nen anant anataenn nanna 122 Pilotsfor DESCRITO ociosos to aa 122 Compensate Crosstalk MIMO oniv anar cnn nc nana 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 215 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Phase Tracking Activates 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 216 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
362. sult 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 8 Tracking and Channel Estimation on page 120 The MinHold Maxhold and Aver age traces are displayed ees User Manual 1176 8551 02 06 30 R amp S FPS K91 Measurements and Result Displays 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 Stream2 Stream3 Stream 4 2 1 Stream 1 2 2 Stream 2 Symb 1 35 2 Symb Symb 352 Symb 1 35 2 Symb 2 3 Stream 3 2 4 Stream 4 92 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 246 or CONFigure BURSt EVM ESYMbol IMMediate on page 186 Querying results TRACe lt n gt DATA see chapter 11 9 4 12 EVM vs Symbol on page 294 FFT Spectrum This result display 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 User Manual 1176 8551 02 06 31 R amp S
363. surements e Constellation diagram for demodulated signal Constellation diagram for individual carriers e Q offset and UO imbalance e Modulation error EVM for individual carriers or symbols Amplitude response and group delay distortion spectrum flatness Carrier and symbol frequency errors Further measurements and results Amplitude statistics CCDF and crest factor e FFT also over a selected part of the signal e g preamble e Payload bit information e Freq Phase Err vs Preamble This user manual contains a description of the functionality that is specific to the appli cation including remote control operation Functions that are not discussed in this manual are the same as in the Spectrum appli cation and are described in the R amp S FPS User Manual The latest version is available for download at the product homepage http www2 rohde schwarz com product FPS html Installation You can find detailed installation instructions in the R amp S FPS Getting Started manual or in the Release Notes Starting the WLAN Application 2 1 Starting the WLAN Application The WLAN measurements require a special application on the R amp S FPS o Manual operation via an external monitor and mouse Although the R amp S FPS does not have a built in display it is possible to operate it inter actively in manual mode using a graphical user interface with an external monitor and a mouse connected It is recommended that y
364. t MINimum This command returns the Bit Error Rate BER for Pilots average maximum or mini mum value in for the IEEE 802 11n MIMO standard For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 12 Return values lt Result gt lt Global Result gt lt Stream 1 result gt lt Stream n result gt Usage Query only FETCh BURSt CPERror AVERage FETCh BURSt CPERror MAXimum FETCh BURSt CPERror MINimum This command returns the common phase error average maximum or minimum value in degrees for the IEEE 802 11n MIMO standard For details see chap ter 3 1 1 Modulation Accuracy Flatness and Tolerance Parameters on page 12 Parameters lt Result gt Stream 1 result Stream n result 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 12 Usage Query only Retrieving Results 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 For details see chapter 3 1 1 Modulation Accuracy Flatness and Tolerance Parame ters on page 12
365. t 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 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 Measurements 92 e Contiguralorm OWVSlVIBW a Maden nnde b prid Ee d c eae ce d 93 e Ee le e EE 95 e nputand Frontend Settings e eeu eere oda 96 e Signal Capture Data Acquisition 105 e Application Data MS citt nte ert c ric e nt te rater ceed 119 e Synchronization and OFDM Demodulation eese 119 e Tracking and Channel Eetmaton nn nn n nano nnnnnnnnnns 120 e Domno iaie ertt tret dert a x t t c td d an td 123 LEE Evaluation Range iaa ad 138 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance e Result Enter tae ees nade a eae a Let 143 Automate SOWING S cis ee coe er eR ENEE SEET 149 SS om 150 5 3 1 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 center frequency and frequency offset reference level and reference level offset attenuation input coupling e YIG filter state After initial setup
366. t float gt 111 lt float gt lt ArrayOfFloat gt lt Min gt lt Max gt lt ArrayOfFloat length 256 gt float 67 float lt float gt 69 lt float gt lt float gt 70 lt float gt lt float gt 69 lt float gt lt ArrayOfFloat gt lt Max gt lt Spectrum gt IQ Histogram width 64 height 64 gt 0123456789 0 lt Histogram gt IQ lt Channel gt lt ArrayOfChannel gt lt PreviewData gt A 2 2 Q Data Binary File The I Q data is saved in binary format according to the format and data type specified in the XML file see Format element and DataType element To allow reading and writing of streamed 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 Q Data File Format iq tar ples for channel 0 channel 1 channel 2 etc If the NumberOfChannels element is not defined one channel is presumed Example Element order for real data 1 channel I 0 Real sample 0 11 Real sample 1 I 2 Real sample 2 Example Element order for complex cartesian data 1 channel I 0 Q 0 Real and imaginary part of complex sample 0 I 1 O 1 Real and imaginary part of complex sample 1 I 2 1 21 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
367. t hand side of the figure After bandpass filtering the signal is sam pled by an analog to digital converter ADC at a sample rate oft This digital Signal Processing for Multicarrier Measurements IEEE 802 11a g OFDM j p 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 E Ese o gm S 8 pepe P FIR UH am pilots data data E user defined compensation meme f estimation of gain frequency o A EA ki E oz E B oc 2 c E 6 o n INS SS eh Fig 4 1 Block diagram for the R amp S FPS WLAN application using the IEEE 802 11a g OFDM j or p standard In the lower part of the figure the subsequent digital signal processing is shown R amp S FPS K91 Measurement Basics 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 Furthermore 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 u
368. t path cuc M 193 Display Configuration softkey sess 91 Understanding csi aida 9 Drop out time MOTE uenerit ie terrens 84 110 Duplicating Measurement channel remote 180 E Electronic input attenuation sssrinin 104 Errors Calculating parameters sasi sirnaininsns aa 61 Calculating parameters IEEE 802 11a g OFDM j p di s 09 Center frequency 2 12 crosstalk x215 E RE 19 Gain imbalance oooooooccccncconocococnnnncnnconanonnnnnon 12 16 18 1 Q offset UO skew Messages Phase drift Pilots BD ascos co 122 215 216 PPDU timing 122 217 Quadrature phase angle Q 17 18 Quiadrat re OI Sel 5 2 rias 12 Status DIIS auccm teta a eet i aee 302 Symbol TIMING s esca itii id 12 Estimates Signal processing IEEE 802 11a g OFDM j p 59 Estimating Channels IEEE 802 11a g OFDM j p 63 Evaluation methods Frequency sweep measurement cococcccncccccnncccccnancnn nns 54 Remote esatto on Trace data sg WEAN EE Evaluation range Remote io 230 ResultdiSplays t peti nt eo 138 e O 156 EVM leien eet dirt asas 12 Calculating IEEE 802 11a g OFDM j p i063 Calculating WLAN 6 rnnt ce 19 Datarcamie fS Siani medies g
369. t 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 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 FPS at any time 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 How
370. tate gt ON OFF 0 1 RST 1 Example INP EATT AUTO OFF Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Manual operation See Using Electronic Attenuation on page 104 INPut EATT STATe lt State gt This command turns the electronic attenuator on and off This command requires the electronic attenuation hardware option Parameters lt State gt ON OFF RST OFF Example INP EATT STAT ON Switches the electronic attenuator into the signal path Manual operation See Using Electronic Attenuation on page 104 INPut GAIN STATe lt State gt This command turns the preamplifier on and off If activated the input signal is amplified by 20 dB If option R amp S FPS B22 is installed the preamplifier is only active below 7 GHz If option R amp S FPS B24 is installed the preamplifier is active for all frequencies Parameters lt State gt ON OFF RST OFF Example INP GAIN STAT ON Switches on 20 dB preamplification Usage SCPI confirmed Manual operation See Preamplifier option B22 B24 on page 105 11 5 4 Signal Capturing The following commands are required to configure how much and how data is captured from the input signal MSRA operating mode In MSRA operating mode only the MSRA Master channel actually captures data from the input signal The data acquisition settings for the R amp S FSW WLAN application in MSRA mode define the application data extract For
371. tated 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 FPS follow the SCPI syntax rules e Asynchronous commands A command which does not automatically finish executing before the next com mand starts executing overlapping command is indicated as an Asynchronous command Reset values RST Default parameter values that are used directly after resetting the instrument RST command are indicated as RST values if available Default unit This is the unit used for numeric values if no other unit is provided with the parame ter 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
372. td 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 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 GI Guard interval length PPDU must have to be measured 1 short Gl used after HT training 0 otherwise Ness Number of extension spatial streams Ngss see Extension Spatial Streams sounding on page 135 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 convolution coder Set to 0 The values for the individual demodulation parameters are described in chapter 5 3 9 Demodulation on page 123 The following abbreviations are used in the Signal Field table Table 3 8 Abbreviations for demodulation parameters shown in Signal Fiel
373. ter 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 iecit tnter is 203 e Configuring the Trigger OU coros dao RR da 208 Configuring the Triggering Conditions TRIGH SEQUENCE E 204 TRIGger SEQuence HOLBot TIME 21 22 22 oir oerte EEN EERSTEN 204 TRIGger SEQuence IF PowetHOLDbDoft tti rario REESEN 204 TRIGger SEQuence IFPower HYS Teresis enun aia aeaa gan cR sacs 204 TRiGoert GtOuencell EVell EN Temalcportzl sss 205 TRIGger GEQuencelEEVell P POWOF aora 205 TRlGoert GtOuencell EVelJObower nennen nennen nnn nnns 205 TRIGger SEQuence LEVelPOWerAU TQ de diia 206 TRIGger SEQuence LEVel RFBOWSeL coitus a 206 TRIGger SEQuence SLOPS esciieceeeie epe aaa 206 TRIGger SEQuehcel SO SG ttd etta tarot trus dad 207 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance TRIGger SEQuence DTIMe lt DropoutTime gt Defines the time the input signal must stay below the trigger level before a trigger is detected again Parameters lt DropoutTime gt Dropout time of the trigger Range Osto10 0s RST Os Manual operation See Drop Out Time on page 110 TRIGger SEQuence HOLDoff TIME lt Offset gt Defines the time offset between the trigger event and the start of the measurement
374. 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 216 Compensate Crosstalk MIMO only Activates or deactivates the compensation for crosstalk in MIMO measurement setups This setting is only available for standard IEEE 802 11ac or n MIMO By default full MIMO equalizing is performed by the R amp S FSW WLAN application However you can deactivate compensation for crosstalk In this case simple main path equalizing is performed only for direct connections between Tx and Rx antennas disregarding ancillary transmission between the main paths crosstalk This is useful to investigate the effects of crosstalk on results such as EVM On the other hand for cable connections which have practically no crosstalk you may get better EVM results if crosstalk is compensated for For details see chapter 4 3 6 Crosstalk and Spectrum Flatness on page 78 Remote command SENSe TRACking CROSstalk on page
375. 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 Stream 1 4 Stream 1 Stream2 Stream3 Stream 4 2 2 Stream 2 Carrier 122 Carrier 122 25 C r4 Carrier 122 Carrier 122 Fig 3 11 Constellation vs carrier result display for IEEE 802 11n MIMO measurements The numeric trace results for this evaluation method are described in on page 293 Remote command LAY ADD 1 RIGH CVC see on page 246 or on page 185 Querying results see on page 293 User Manual 1176 8551 02 06 28 R amp S FPS K91 Measurements and Result Displays 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 120 The Minhold Average and Maxhold traces are displayed This result display is not available for single carrier measurements IEEE 802 11b g DSSS EVM vs Carrier ei Mine 2 Avge3 Max Carrier 250 50 1 Carrier Carrier 250 Stream 1 A Stream 1 Stream2 Stream3 Stream 4 3 2 Stream 2 Carrier 122 Carrier 122 Carrier 122 3 3 Stream 3 3 4 Stream 4 Carrier 122 25 Carrier Carrier 122 Carrier 122 25 Carrier Carrier 122 Fig 3 12
376. 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 which is available at the bottom of all softkey menus Overview 1 LISTE WLAN
377. ther 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 files inside the tar file are not changed not com pressed and thus it is possible to read the UO data directly within the archive without the need to unpack untar the tar file first Q Data File Format iq tar A 2 1 Sample iq tar files If you have the optional R amp S FPS VSA application R amp S FPS K70 some sample iq tar files are provided in the C R S Instr user vsa DemoSignals directory on the R amp S FPS Contained files An iq tar file must contain the following files e Q parameter XML file e g xyz xm1 Contains meta information about the UO data e g sample rate The filename can be defined freely but there must be only one single I Q parameter XML file inside an iq tar file e Q data binary file e g xyz complex f10oat32 Contains the binary l Q data of all channels
378. this value you can determine the noise power of the R amp S FPS 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 98 Receiving and Providing Trigger Signals Using one of the TRG IN AUX connectors of the R amp S FPS the R amp S FPS can use a signal from an external reference as a trigger to capture data Alternatively the internal R amp S FPS K91 Measurement Basics El trigger signal used by the R amp S FPS can be output for use by other connected devices Using the same trigger on several devices is useful to synchronize the transmitted and received signals within a measurement For details on the connectors see the R amp S FPS Getting Started manual External trigger as input If the trigger signal for the R amp S FPS is provided by an external reference the reference signal source must be connected to the R amp S FPS and the trigger source must be defined as External for the R amp S FPS Trigger output The R amp S FPS can provide output to another device either to pass on the internal trig ger signal or to indicate that the R amp S FPS itself is ready to trigger The trigger signal can be output by the R amp S FPS automatically or manually by the user If it is provided automatically a high signal is output when the R amp S FPS has tri
379. ting Channels eterne rhe niin nel 94 Default values rre eren 92 nee abu 111 Programming examples SEM c HT 311 uci 308 WEAN doni iis Ha td Rc eed cte e P eerta 308 PSDU ADD Oir ci 65 PvT Falling edge result display sissien 41 ull PPIDU 2 ccr teret tesa 187 Full PPDU result display ente 39 Rising amp Falling i Rising edge result display sessessssss 40 PvT Full Burst Trace datae tcs 296 Q Quadrature Offset castes iii 17 18 EMO 12 R Record length A steven EE Relationship to sample rate Reference frequency Coupling MIMO E 119 Reference level Auto NEEN 104 150 Auto level continuous eene 102 Default erc 92 ole zs 108 Offset softkey 103 Unit 2n 103 UU 103 Refreshing MSRA Applications eco ti tette et oes 151 MSRA applications remote ssssss 242 iei 151 Remote commands Basics ON Bu E 175 Boolean values Capitalization Character data n Data blocks Zaireen alii Numeric values Obsolete Optional keywords Parameters cecinere 177 ug 179 SIUS Pn 176 Restoring Chanrnel settings ertet the 94 Result configuration A maitre eee Ete dean 143 Result displays ANA Micra ca te AM EVM vo AMP Misa ceci les A A ek over Les testate dre
380. tion 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 FPS 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 KAS n X ref n n N 1 gt IX er n 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 N 1 3 le n 0 EVM X ref n 3 TI o WLAN UO Measurement Modulation Accuracy Flatness and Tolerance 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 so
381. tion Accuracy Flatness and Tolerance Parameters for WLAN Signals 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 In MSRA mode you may want to stop the continuous measurement mode by the Sequencer and perform a single data acquisition a Select the Sequencer icon El from the toolbar b Set the Sequencer state to OFF c Press the RUN SINGLE key Measurement results are updated once the measurement has completed To select the application data for MSRA measurements In multi standard radio analysis you can analyze the data captured by the MSRA Mas ter in the R amp S FSW WLAN application Assuming you have detected a suspect area of the captured data in another application you would now like to analyze the same data in the R amp S FSW WLAN application 1 Select the Overview softkey to display the Overview for WLAN UO measure ments 2 Select the Signal Capture button 3 Define the application data range as the Capture Time 4 Define the starting point of the application data as the Capture offset The offset is calculated according to the following formula capture offset sta
382. tion 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 Remote command LAY ADD or 1 RIGH SFI see LAYout ADD WINDow on page 246 CONFigure BURSt STATistics SFIeld IMMediate on page 189 Querying results TRACe lt n gt DATA see chapter 11 9 4 18 Signal Field on page 297 IESSE User Manual 1176 8551 02 06 38 R amp S FPS K91 Measurements and Result Displays PvT Full PPDU Displays the minimum average and maximum power vs time diagram for all PPDUs 3 PVT Full PPDU e Min 2 Avg 3 Max ii MA Start 5 0 ps 100 02 ms Stop 165 0 ps Fig 3 19 PvT Full PPDU result display for IEEE 802 11a g OFDM ac n p standards 2 PVT Full PPDU RXIN4 Rx 1 Rx2 Rx3 Rx4 2 1 Rx 1 et Mine 2 Avg 3 Max 116 625 us 625 0 ns 11 73 ps 24Rx 4 116 625 us 625 0 ns 11 73 yis Fig 3 20 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 User Manual 1176 8551 02 06 39 R amp S FPS K91 Measurements and Result Displays 1 P
383. 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 51 In these measurements demodulation is not performed Selecting the measurement type WLAN measurements require a special operating mode on the R amp S FPS which you activate using the MODE key gt To selecta 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 In the Select Measurement dialog box select the required measurement The R amp S FPS WLAN application uses the functionality of the R amp S FPS 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 selected 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 Frequency Sweep Measurements 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 FPS User Manual The measurement specific settin
384. to the WLAN IQ measurement are described here o The WLAN IQ measurement captures the UO data from the WLAN signal using a Note that the CONF BURS ResultType 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 11 7 Configuring the Result Display on page 244 e Selecting the WLAN IQ Measurement Modulation Accuracy Flatness and Toler e Selecting a Common RF Measurement for WLAN Signals 190 11 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 The selected measurement must be started explicitely see chapter 11 8 Starting a Measurement on page 259 CONFigure BURSEAM AM IMMediate auod aucun noz io e euet aee eda edad 185 CONFigure BURStAM EVM IMMediate cessere 185 CONFIgure BURSEAMIPMEIMMediate 2 orta tb tento tte rete aaaea 185 CONFloure BURGCCONSt CCAbRrtertJMMedatel AAA 185 CONFloure BURGCCONSt CSxvMboltlMMedatel scenici isanrn iniaa 185 CONFloure BURGCEVM EC Arer IMMediatel nennen 186 CONFigure BURSt EVM ESYMbol MMedi
385. tomatically 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 This function is only available for the MSRA Master not for the applications Remote command CONFigure POWer AUTO on page 198 RF Attenuation Defines the attenuation applied to the RF input Attenuation Mode Value RF Attenuation The RF attenuation can be set automatically as a function of the selected reference level Auto mode This ensures that the optimum RF attenuation is always used It is the default setting By default and when Using Electronic Attenuation is not available mechanical attenua tion is applied In Manual mode you can set the RF attenuation in 1 dB steps down to 0 dB Other entries are rounded to the next integer value The range is specified in the data sheet If the defined reference level cannot be set for the defined RF attenuation the refer ence level is adjusted accordingly and the warning Limit reached is displayed 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 hardw
386. trigger events caused by noise oscillation around the trigger level This setting is only available for IF Power trigger sources The range of the value is between 3 dB and 50 dB with a step width of 1 dB For more information see chapter 4 9 2 Trigger Hysteresis on page 84 Remote command TRIGger SEQuence IFPower HYSTeresis on page 204 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 85 Remote command TRIGger SEQuence IFPower HOLDoff on page 204 Slope Trigger Source Settings For all trigger sources except time you can define whether triggering occurs when the signal rises to the trigger level or falls down to it Remote command TRIGger SEQuence SLOPe on page 206 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 114 The Trigger Source is automatically set to External Trigger 1 2 The required connec tions between the analyzers the trigger unit and the DUT are indicated in the graphic WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Fo
387. ts the external trigger input as source of the trigger signal See Trigger Source on page 109 See Free Run on page 109 See External Trigger 1 2 on page 109 See RF Power on page 109 See UO Power on page 110 See FS Z11 Trigger on page 111 Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Configuring the Trigger Output The following commands are required to send the trigger signal to one of the variable TRIGGER INPUT OUTPUT connectors OUTPut TRIGger port DI Rection 5 2 2 atri tta toto ei 208 QUTPut TRIGger port LEVel eeerei ree ere enun rae rit n a EENS a eB a 208 OINTPut bRIGSerspoltscO YD ete adds eee te tua tt tesa ree tob ette Ree etam rend 209 OUTPubETRIGger port PULSe MMediate 2 ire na nre RENE 209 OUTPut TRIGger port PULSe LENGIR e eeeeeeee eee eene eene EEN nnn nennt anna ann 209 OUTPut TRIGger lt port gt DIRection Direction This command selects the trigger direction for trigger ports that serve as an input as well as an output Suffix port Selects the used trigger port 2 TRG AUX Parameters lt Direction gt INPut Port works as an input OUTPut Port works as an output RST INPut Manual operation See Trigger 2 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
388. ttings for IEEE 802 11a g OFDM ac j n p 138 e Evaluation Range Settings for IEEE 802 11b o DGpe ee 141 5 3 10 1 Evaluation Range Settings for IEEE 802 11a g OFDM ac j n p The following settings are available to configure the evaluation range for standards IEEE 802 11a g OFDM ac j n p WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Evalu PPDU to analyze Analyze this PPDU PPDU to Analyze Statistics PPDU Statistic Count No of PPDU s to Analyze Time Domain Source of Payload Length Equal PPDU Length Min No of Data Symbols Max No of Data Symbols Fig 5 6 Evaluation range settings for IEEE 802 11a ac g OFDM j n p standards Analyze this PPDU PPDU to Anahyze enne 139 PPDU Statistic Count No of PPDUs to Anahyze nees 140 Source or Payload Meng iii ute cn ente at abe Dd 140 Equal PPDU Long T 140 MinJMax No of Data Symbols 2 teet er te Rex annt binnen 140 Analyze this PPDU PPDU to Analyze If enabled the WLAN I Q results are based on one individual PPDU only namely the defined PPDU to Analyze The result displays are updated to show the results for the the new evaluation range The selected PPDU is marked by a blue bar in PPDU based results see Magnitude Capture on page 35 Note AM AM AM EVM and AM PM results are not updated when single PPDU analy sis is selected In MSRA mode single PPDU an
389. uals 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 programming Online help is available using the Y icon on the toolbar of the R amp S FPS Getting Started This manual is delivered with the instrument in printed form and in PDF format on the CD ROM It provides the information needed to set up and start working with the instrument Basic operations and handling are described Safety information is also included The Getting Started manual in various languages is also available for download from the Rohde amp Schwarz website on the R amp S FPS product page at http www rohde schwarz com product FPS html User Manuals User manuals are provided for the base unit and each additional firmware application The user manuals are available in PDF format in printable form on the Documenta tion CD ROM delivered with the instrument In the user manuals all instrument func tions are described in detail Furthermore they provide a complete description of the remote control commands with programming examples The user manual for the base unit provides basic information on operating the R amp S FPS in general and the Spectrum application in particular Furthermore the soft ware functions that enhance t
390. ue is returned as a floating point number expressed in units of dB Supported data formats see FORMat DATA on page 283 ASCii UINT Example For EVM the EVM of the m th analyzed PPDU for the subcarrier n 1 2 Nusea TRACE1 Minimum EVM value per subcarrier Minimum EVM 4 EVMo 4 EVMstatistic Length 1 Minimum EVM value for subcarrier Nuseg 1 2 Minimum EVM 2 EVM 5 EVMstatistic Length 2 H Minimum EVM value for subcarrier Nyseq 1 2 1 Minimum EVM nused EVM nused pues EVMstatistic Length Nused H Minimum EVM value for subcarrier Nuseq 1 2 11 9 4 11 EVM vs Chip These results are 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 available TRACE1 EVM IEEE values TRACE2 EVM Direct values Each trace shows the EVM value as measured over the complete capture period The number of repeating groups that are returned is equal to the number of measured chips Each EVM value is returned as a floating point number expressed in units of dBm Supported data formats see FORMat DATA on page 283 ASCii REAL 11 9 4 12 EVM vs Symbol Three traces types are available with this measurement The basic trace types show either the minimum mean or maximum EVM value as measured over the complete capture period 11 9 4 13 11 9
391. uence SLOPe lt Type gt For external and time domain trigger sources you can define whether triggering occurs when the signal rises to the trigger level or falls down to it Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Parameters lt Type gt Example Manual operation 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 TRIG SLOP NEG See Slope on page 111 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 Parameters lt Source gt Example Manual operation IMMediate Free Run EXTernal Trigger signal from the TRIGGER IN connector EXT2 Trigger signal from the TRIGGER AUX connector RFPower First intermediate frequency IFPower Second intermediate frequency IQPower Magnitude of sampled UO data For applications that process l Q data such as the UO Analyzer or optional applications RST IMMediate TRIG SOUR EXT Selec
392. ues 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 11 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 No trace data is available for the following evaluation methods Magnitude Capture e Result Summary Global Detailed As opposed to the R amp S FPS base unit the window suffix lt n gt is not considered in the R amp S FPS 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 to simplify the description Retrieving Results 96 ZZ uonenbe ZLOZ YJE L za oer rzogd 3331 9 S6 zc uonenbe Z OZ YJE L za oer rzogd 3331 s y6 ZZ uonenbe ZLOZ YEW L za oel rzogd 3331 p 68 02 uonenbe zL0z L1 z08 PIS 3331
393. ult 2 52 ET Drop out tifTie ree re teret tr rn DA A O External remote Holdoff us Hysteresis Measurements Offset OUTPUT e lI I S Synchronization Trigger level AUO ees Auto remote External trigger remote A 205 VQ Power remote A 205 IF Power remote oe eene eerte ine 205 RF Power remote i eene dies 206 Bebe Ge EE 109 o pto dE 109 Free RUM p 109 VO RT 110 RF POW T EE 109 Troubleshootirig cocina 171 U Units EVMrteSUltS aiius a 275 Gain imbalance results sisine assisi maien 275 PPDU length re SUS rnit tt ittm enitn 267 Preamble resus estira nmt terea 275 Refererice levella itcc etse ais 103 Updating Result display 32 a rrt e cho bota 151 Result display remote AAA 242 Usable UO bandwidth Definition User manuals User sample rate Definition ice rtm b meten oe a tne edad 313 Ww Window title Dar migannen a tite neta 11 Windows Adding remote tie ei tete ee 246 Closing remote airada pas 249 252 CONTIQUIING icc Ha dc e pt 94 Layout remote 249 Maximizing remote we 245 Querying remote cette entera 248 Replacing remote esee 249 Splitting remote Types remote s epe nn defe WLAN Measu remehis etienne re ir ged Measurements step by step E SA iarsna ia Programming
394. 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 291 Retrieving Results 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 N CCDF 0 CCDF 1 10 CCDF 2 10 CCDF N 1 10 11 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 Na pairs of and Q data per OFDM Symbol OFDM Symbol 1 li Q 4 Uu aah Uwe Q1 nst OFDM Symbol 2 l2 1 Q21 122 Q22 la usc Q2nst OFDM Symbol N Uu Quits I
395. umed 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 225 IEEE 802 11 b g DSSS FMMD All PPDUs are assumed to have the specified PPDU format see SENSe DEMod FORMat BANalyze on page 225 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 124 See PSDU Modulation to use on page 125 See PPDU Format to measure PSDU Modulation to use on page 131 SENSe DEMod FORMat BCONtent AUTO State This command determines whether the PPDUS to be analyzed are determined auto matically or by the user Parameters State 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
396. uplingType gt AC AC coupling DC DC coupling RST AC Example INP COUP DC Usage SCPI confirmed Manual operation See Input Coupling on page 97 INPut DPATh lt State gt Enables or disables the use of the direct path for frequencies close to 0 Hz Parameters lt State gt AUTO 1 Default the direct path is used automatically for frequencies close to 0 Hz OFF 0 The analog mixer path is always used RST 1 Example INP DPAT OFF Usage SCPI confirmed INPut FILTer YIG STATe State This command turns the YIG preselector on and off Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Tolerance Note the special conditions and restrictions for the YIG filter described in YIG Prese lector on page 97 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 97 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 Q 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 500 Example INP IMP 75 Usage SCPI con
397. urce Sete cured urge harte ite paire pee t Pre ped eaae 96 e OUIDUL SS gs uet eet dde reti seda use eta d eed ent env 98 FREQUENCY Te CN 100 e Amplitude Geittngs A 101 5 3 4 1 Input Source Settings The input source determines which data the R amp S FPS 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 E The Digital UO input source is currently not available in the R amp S FPS WLAN applica tion Radio Frequency INpPUE dci a Ed ei 96 Radio Frequency Input The default input source for the R amp S FPS is Radio Frequency i e the signal at the RF INPUT connector of the R amp S FPS If no additional options are installed this is the only available input source WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Input Input Source Frequency Input Coupling Digital IQ Impedance YIG Preselector Radio Frequency Staten rr aei rre ied a er Ecl ra Le oti E aeo 97 Jal cit gh ers Uere A 97 IMPE ANCS Tm 97 WG PISS SCION EE 97 Radio Frequency State Activates input from the RF INPUT connector Remote command INPut SELect on page 194 Input Coupling The RF input of the R amp S FPS can be coupled by alternating current AC or direct cur rent DC AC coupling blocks any DC voltage from the input signal This is the default setting t
398. ut signal must be in the frequency range between 500 MHz and 7 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 instrument s data sheet Note If the input signal contains frequencies outside of this range e g for fullspan measurements the measurement 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 Remote command TRIG SOUR RFP see TRIGger SEQuence SOURce on page 207 UO Power Trigger Source lt Trigger Source Settings Triggers the measurement when the magnitude of the sampled UO data exceeds the trigger threshold The trigger bandwidth corresponds to the Usable I Q Bandwidth which depends on the sample rate of the captured UO data see Input Sample Rate on page 106 and chapter A 1 Sample Rate and Maximum Usable UO Bandwidth for RF Input on page 313 Remote command TRIG SOUR IQP see TRIGger SEQuence SOURce on page 207 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
399. utomatically Auto Level Automatically determines the optimal reference level for the current input data At the same time the internal attenuators are adjusted so the signal to noise ratio is opti mized while signal compression clipping and overload conditions are minimized To determine the optimal reference level a level measurement is performed on the R amp S FPS Remote command SENSe ADJust LEVel on page 240 Sweep Settings The sweep settings define how the data is measured Continuous Sweep RUN CONT c cccecceeencceseeeeeeeeeeceaeeseeaaeeseaeeseeaaeesseneeseaeeesenees 150 Single Sweep RUN GINGLE A 150 Continue Single SWEEP usaran a 150 hi 151 Continuous Sweep RUN CONT After triggering starts the measurement and repeats it continuously until stopped While the measurement is running the Continuous Sweep softkey and the RUN CONT key are 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 lt n gt CONTinuous on page 261 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 abort
400. utput 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 209 MIMO Capture Settings The following settings are only available for the IEEE 802 11ac and n standards WLAN 1 Signal Capture Trigger Source Trigger In Out MIMO Capture DUT MIMO Config 1 Tx Antenna gt MIMO Antenna Signal Capture Setup om Simultaneous Sequential using OSP Switch Box L i Sequential Manual Simultaneous Signal Capture Setup using 1 Rx Channel s Tn amenna na gt 2 es E B O 4 On Joined Rx Synchronization and Tracking WLAN IQ Measurement Modulation Accuracy Flatness Tolerance DUT MIMO GOHRIIOBSUOEL 2 221 uted repe ete andlor ltd 114 MIMO Antenna Signal Capture Geiup nens 114 Simultaneous Signal Capture Setup sess 114 A A A AA 115 L Analyzer IP A 115 E UL NM TN TT TE 115 L Joined RX Syne and Traci eee ripae trennen 115 Sequential Using OSP Switeli Setup iioi ria 115 EE 116 L OSP Switch Bank Configuration ssscecsssesesecsseceeesssessesseeteseneseceees 117 Manual Sequential MIMO Data Caplule cato tatg ptt tetro Reto sass anie ns 117 o A O e 118 L Cale RASUS 118 L Clear All Magnitude Capture Butters 118 L RUN SGL RUN CONT updates 118 Reference Frequenc
401. vating WLAN Measurements AA 180 e Selecting a Messi eme conti Ieri encre bred ard e cea dt e e nt d d 183 e Configuring the WLAN IQ Measurement Modulation Accuracy Flatness and Toler ci T XX 191 e Configuring Frequency Sweep Measurements on WLAN Signals 242 e Configuring the Result Display iei etti 244 Starting a Measurement EE 259 e Retrieving Resuhts nennen nennen nnn nennen 264 ENEE 298 e Salus E iio dette watt tex iia E M IUe 301 e Commands for Compatibility seen 306 e Programming Examples R amp S FPS IKO9T tta ctt AE 308 11 1 Common Suffixes For the description of the remote commands in the WLAN application the following common suffixes are used Table 11 1 Common suffixes for WLAN measurements on l Q data Suffix Value range Description n 1 16 Window lt k gt 1 8 Limit 11 2 11 2 1 Introduction Suffix Value range Description lt t gt 1 Trace lt m gt 1 4 Marker Table 11 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 operat
402. ver WLAN 802 11 applications cannot perform data acqui sition in MSRA operating mode Useful commands for automatic configuration described elsewhere e CONFigure POWer AUTO on page 198 e CONFigure POWer AUTO SWEep TIME on page 198 Remote commands exclusive to automatic configuration SENSE DIDIT Ii ion 240 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 FPS 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 Level on page 150 Configuring the Application Data Range MSRA mode only In MSRA operating mode only the MSRA Master actually captures data the MSRA applications define an extract of the captured data for analysis referred to as the application data For the R amp S FSW WLAN application the application data range is defined by the same commands used to define the signal capture in Signal and Spectrum Analyzer mode see chapter 11 5 4 Signal Capturing on page 201 Be sure to select the cor rect measurement channel before executing this command In addition a capture offset can be defined i
403. vision 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 FPS 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 antenna and the complementary blocks in reverse order applied at the receive antenna Spatial Space Time Transmit Receive Space Time Spatial
404. 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 ZOOM STATe State This command turns the zoom on and off Parameters lt State gt ON OFF RST OFF Example DISP ZOOM ON Activates the zoom mode 11 10 2 2 Using the Multiple Zoom DISPlay WINDow n ZOOM MULTiple zoom AREA eese 301 DiSblavlfWiNDow nztZOOM ML Tiple zoomzGTATe nono nanannananannnn 301 User Manual 1176 8551 02 06 300 R amp S FPS K91 Remote Commands for WLAN Measurements H DISPlay WINDow lt n gt ZOOM 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 e Span 25 0 MHZ d CF 2 000519931 GHz 498 pts 1 24 MHz Span 12 435008666 MHz 1 origin of coordinate system x1 0 y1 0 2 end point of system x2 100 y2 100 3 zoom area e g x1 60 y1 30 x2 80 y2 75 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
405. y Parameters lt ChannelType gt Channel type of the new channel For a list of available channel types see INSTrument LIST on page 181 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 181 Example INST CRE SAN Spectrum 2 Adds an additional spectrum display named Spectrum 2 INSTrument CREate REPLace lt ChannelName1 gt lt ChannelType gt lt ChannelName2 gt This command replaces a measurement channel with another one Setting parameters lt ChannelName1 gt String containing the name of the measurement channel you want to replace lt ChannelType gt Channel type of the new channel For a list of available channel types see INSTrument LIST on page 181 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 181 Example INST CRE REPL Spectrum2 IQ IQAnalyzer Replaces the channel named Spectrum2 by a new measure ment channel of type IQ Analyzer named IQAnalyzer Usage Setting only INSTrument DELete lt Channel
406. y COMINO concisa add 119 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 211 MIMO Antenna Signal Capture Setup Defines the MIMO method used by the R amp S FPS 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 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 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 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 212 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 WLAN IQ Measurement Modulation Accuracy Flatness Tolerance Color State gray antenna off
407. y the specified PSDU Modulation 3 PPDU Format Long PPDU t SYNC SIGNAL SERVICE LENGTH CRC 128 bits B bits B bits 16 bits 16 bits Long PPDU Format Fig 5 4 Demodulation settings for IEEE 802 11b g DSSS signals PPDU Format to measure PSDU Modulation touse 131 PPDU e irri edt eec E es cette eed 132 PSD UW Mee WEE e EEN 132 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 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 9 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 226 SENSe DEMod FORMat BANal
408. yze on page 225 SENSe lt n gt DEMod FORMat SIGSymbo1 on page 230 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 225 SENSe DEMod FORMat BANalyze BTYPe on page 306 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 225 Demodulation IEEE 802 11n The following settings are available for demodulation of IEEE 802 11n signals Demodulation 80 0MHz Standard IE d La A AS Mae Setun 3 Ty X 3p gt a Na at Data Sumhale L 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 MCS Index STBC Field Auto same type as first PPDU Extension Spatial Streams sounding Auto same type as first PPDU Modulation Data Rate Mb s mcs Index stream 1 stream 2 stream 3 stream 4 800ns GI 400ns GI Guard Interval Length Fig 5 5 Demodulation settings for IEEE 802 11n standard PPDU Analysis e cocina eerte Eyre
409. z com product FPS html gt Downloads gt Firmware 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 2 Welcome to the WLAN Application The R amp S FPS WLAN application extends the functionality of the R amp S FPS 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 IEEE 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 11j e EEE standards 802 11n SISO MIMO e EEE standards 802 11p The R amp S FPS WLAN application features Modulation mea

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