R&S FSV-K70 Firmware Option Vector Signal
Contents
1. C Const 1 o Measkhel IM Cinw O MagAbs Meask amp Ref E E a a a F Stop 2 535 Start 26 sym Stop 174 sym Fig 5 8 R amp S FSV K70 Evaluation lines not properly adjusted All measurement screens that consider the evaluation range are marked with two small red lines in the title bar A Const 1 Q Meas amp Ref 5 6 Comparing the Measurement Signal to the Reference Signal You have seen that it is possible to add different traces such as maximum hold or average to each screen When evaluating the measurement signal it is also possible to display the ideal reference signal as an additional trace This can be a significant help when troubleshooting since it allows for an immediate comparison Start from the configuration described in chapter 5 4 Evaluating the Rising and Falling Edges on page 23 Getting Started 1173 9711 02 01 26 R amp S FSV K70 Measurement Example 2 Burst GSM EDGE Signals SSS RRR RR RR ee eee eee Comparing the Measurement Signal to the Reference Signal 2 Select screen D to set the focus on it 3 Press the TRACE key and then the Trace 2 softkey 4 Select Clear Write as the Trace Mode and Evaluation Ref This adds a second trace to your result display This trace is the ideal reference signal that can now be compared to the measurement signal see figure 5 9 5 To view the traces in more detail enlarge the screen using the Split Maximize key E and zoom into the d2. Trade names are trademarks of the owners The following abbreviations are used throughout this manual R amp S FSV is abbreviated as R amp S FSV R amp S FSV K70 Contents Contents T PFOCCO oneee E EEEE 5 1 1 Documentation OvervieW sssssssssssensnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn ennnen nennen 5 1 2 Conventions Used in the DoCumentatiOn cccssceeeeeeeeeeeeeeeeeeeeeneseeenensaeeeseenesenaes 6 2 Brief Introduction to Vector Signal AnalySis cccsseseeeeeeeeeees 7 3 Connecting the Transmitter and AnalyZev ccccscceseeeeeeseeeeeesees 8 4 Measurement Example 1 Continuous QPSK Signal 00 9 41 Transmitter SCC Siig ccuciencaceceacerstcaretoteniorsanccusausstseanustaincruanndiaamesnvensyctamiersuneniacusanstancies 9 42 Analyz r SCCUNG sasior nna nTn Aiar AAEE ANSERA TAES 11 4 3 Changing the Display Configuration cccccsseeeeseeeeeseeeeeeneeeeeneeseenesseeeeseeneeeeenees 13 4 4 Navigating Through the Capture Buffet ccccssceessseeeseeeeeeeeeeeseeneeeeeneeseeneesannees 16 4 5 Averaging Several Evaluations ccccccccsseeesseeeeeeseeseeeseeseeneesseneeseensessaeessensensannees 17 5 Measurement Example 2 Burst GSM EDGE Signals 19 roa Ms Leh geo 2 eee ie ae eee eee ae ee ee eee ea eee 19 5 2 A alyzer Set GS sius ea Ea EE ieie EEn 21 5 3 Navigating Through the Capture Buffer cc
3. Alpha 0 22 Screen D Stat Mag CapBuf Measurement Evaluation Display Filter On Range Configuration Setto Default Fig 6 1 R amp S FSV K70 Settings Overview dialog box Getting Started 1173 9711 02 01 28 R amp S FSV K70 Brief Overview of the Operating Philosophy Settings Overview The Settings Overview dialog box displays the most important parameters to provide a quick overview of your settings Furthermore it serves as a wizard to guide you through the settings The Settings Overview dialog can be opened with the Settings Over view softkey in the main VSA menu The Settings Overview dialog box consists of nine blocks that can be configured step by step If you have covered all blocks you can be sure that you have not missed an important setting Modulation amp Signal Description This is the most important block for configuring the R amp S FSV K70 Here you describe the structure of your signal e g its modulation its transmit filter whether the signal is bursted or continuous etc Based on this description the R amp S FSV K70 configures most remaining blocks automatically Frontend Includes major settings for the frontend of the analyzer such as the center frequency I Q Capture This block specifies how many I Q data points should be captured Furthermore you can choose the oversampling for the captured data With a high oversampling you can cover a larger bandwidth Burst
4. Quadrature Error 1 02 20 dag i a aE 1 274 dB sym E l i i 11 40 cam Start 0 ym Stop 148 ym p C Mag CapBut 1 Cire Statistic Count Auto Select Result Rng 2 Ls csm i Start 0 sym Stop 10000 sym Fig 5 4 R amp S FSV K70 Navigation through the capture buffer 5 4 Evaluating the Rising and Falling Edges The Result Length is the number of symbols that are to be demodulated and analyzed together In most common applications only the parts of the capture buffer containing the bursts need to be analyzed Hence for bursted signals the Result Length usually coincides with the burst length However there are certain scenarios where the rising and falling edge of a burst are also of interest e g checking the power ramping of the device under test For this measurement task it is useful to choose a Result Length that exceeds the burst length Getting Started 1173 9711 02 01 23 R amp S FSV K70 Measurement Example 2 Burst GSM EDGE Signals EEE Setting the Evaluation Range 1 In order to include the rising and falling edges of the bursts in the EVM vs Time display Screen A you need to increase the Result Length The Result Length is the number of symbols from the capture buffer that are to be demodulated together In the Settings Overview diagram select the Result Range block and increase the Result Length to 200 symbols 2 To evaluate the rising and falling edges furthe
5. FSV K70 Default Screen Layout for Measurement Example 1 4 3 Changing the Display Configuration gt To change the screen layout i e the display configuration do one of the following e Select the Display Config softkey in the main VSA menu e Select the Display Configuration block in the Settings Overview diagram e Press the MEAS key Predefined Display Configurations Some predefined display configurations for specific modulations are available in the Predefined tab The most common measurements for one specific modulation can then be selected with just one click For example if you are unsure about the characteristics of your signal you should select the predefined Signal Overview configuration as this display configuration gives you a general overview of your signal Getting Started 1173 9711 02 01 13 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal EE EE Changing the Display Configuration Display Configuration Predefined A Result Summary B Result Summary C Mag CapBuf D Symbol Table FSK typical configuration Freq Error Rel B Result Summary Mag CapBuf D FreqCons Meas amp Ref MSK typical configuration Phase Error B Result Summary Mag CapBuf O Freq Error Rel PSK QAM typical configuration EVM B Result Summary Mag CapBurt D IZQ Const Meas amp Ref Signal Overview Mag CapBut B Spec RealImag CapBuf Result Summary D 1 9 Const Mea
6. Introduction to Vector Signal Analy sis the key task of the vector signal analysis software is to reconstruct the ideal signal We try to perform this reconstruction based on the knowledge about the DUT that you provide Therefore we have introduced a dialog box in which you can describe your signal There you specify whether you have a continuous or a bursted signal the mod ulation of your signal the symbol rate the transmit filter whether your signal contains a known training sequence pattern etc This dialog box starts with the Signal Description and then guides you through the remaining settings However most of the settings will already be configured correctly based on your signal description For example the burst search will be deactivated if you specify a continuous signal Settings Overview yy x Modulation QPSK Symbol Rate 3 84 MHz TS Filter RRC Capture Length 8000 Alpha BT 0 22 Center Freg 15 0 GHz Oversampling 4 Signal Type Continuous Ref Level 10 0 dBm Dig Filter BW 1 2279E 07 Burst Length 102 1600 Attenuation 10 dB Trigger Mode Free Run Pattern Preamp Off Trigger Offset 0 0 sym Modulation Signal Description Frontend I Q Capture Res Length 600 Reference CAPTURE Alignment LEFT Burst Pattern Search Off Off Demodulation Result Range Screen 4 IZQ Const Meas amp Ref Screen 6 Result Summary Meas Filter RRC Entire Result Range Screen C Mag CapBuf
7. Type EVM 4 4 Navigating Through the Capture Buffer Using the R amp S FSV K70 option you can navigate through the capture buffer i e control which part of the capture buffer is currently analyzed Note In Spectrum mode this functionality is referred to as gating 1 Inthe measurement display take a closer look at screen C magnitude of the capture buffer The green bar shows how far the current measurement has already procee ded i e how much of the signal has been evaluated CMag CapBuf 8 Cir 40 dBm 60 dam 80 dim Start 0 sym stop 8000 sym 2 Press the RUN SINGLE key Since the signal you are currently analyzing is continuous as opposed to containing bursts the entire capture buffer is analyzed and hence will be marked with the green bar The last evaluated result range i e the currently evaluated result range at the time the measurement stopped is highlighted in blue Start 0 sym Stop 6000 sym 3 Togo back to a previously evaluated result range within the same capture buffer press the SWEEP key and then the Select Result Rng softkey By selecting different Getting Started 1173 9711 02 01 16 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Averaging Several Evaluations result ranges for exmaple using hte rotary knob you can move the highlighted blue area through the capture buffer and choose your currently demodulated result range The results for this range are
8. analysis For example if you want to measure a bursted signal it is recommended that you make the capture length long enough to ensure that in all captures at least one entire burst is included Getting Started 1173 9711 02 01 24 R amp S FSV K70 Measurement Example 2 Burst GSM EDGE Signals Setting the Evaluation Range Result Range The Result Length is the number of symbols from the capture buffer that are to be demodulated and analyzed together The Result Range defines the area of the capture buffer in which the symbols are located For example if the signal is bursted the Result Length usually coincides with the burst length and the result range coin cides with the range of the capture buffer in which the burst is located Evaluation Range In some scenarios the result range contains symbols that are not supposed to be considered for the EVM that is to be displayed in the Result Summary One of these scenarios is described in chapter 5 4 Evaluating the Rising and Falling Edges on page 23 The evaluation range is always equal to or smaller than the result range and defines The range over which traces that do not have a time axis are displayed e g polar diagrams The range over which the following parameters are calculated for the Result Summary EVM MER Phase Error Magnitude Error Power Note You need to enlarge the Result Summary with the Split Maximize key faf to see all of these par
9. displayed in the Clear Write trace of the EVM mea surement screen Note Generally all Clear Write traces and the Current column in the Result Sum mary are affected by this selection _ 2 Select Result Range 4 C Mag CapBuf i e GBM LUU dem Start 0 sym Stop 6000 sym 4 5 Averaging Several Evaluations By default all measurement screens are displayed with a single trace which is the Clear Write trace This trace displays the result of the current evaluation i e the highlighted blue area from the example in chapter 4 4 Navigating Through the Capture Buffer on page 16 However for most real world measurement tasks you need to obtain a result that is averaged over a certain number of evaluations or a worst case result of a certain number of evaluations This section explains how to achieve this e The number of evaluations that should be considered can be set via the SWEEP key A e Traces that are averaged over these evaluations e g Max Hold Min Hold Average can be added to the result display via the TRACE key To evaluate EVM vs Time 1 Configure screen A such that it displays the EVM versus time measurement see chapter 4 3 Changing the Display Configuration on page 13 Tap in the screen to set the focus on it 2 Todisplay the trace averaged over several measurements or the maximum hold trace over several measurements press the TRACE key 3 Add further traces by pressing
10. refer to the test transmitter documenta tion Operating Manual The operating manual describes the specific instrument functions of the option in detail It also includes background information on vector signal analysis as well as trouble shooting information For additional information on default settings and parameters refer to the data sheets Basic information on operating the R amp S FSV is not included see the base unit docu mentation for that Online Help The online help contains context specific help on operating the R amp S FSV including the K70 option It describes both manual and remote operation The online help is installed on the R amp S FSV by default Getting Started 1173 9711 02 01 5 R amp S FSV K70 Preface Conventions Used in the Documentation 1 2 Conventions Used in the Documentation 1 2 1 Typographical Conventions The following text markers are used throughout this documentation Graphical user interface ele All names of graphical user interface elements on the screen such as dia ments log boxes menus options buttons and softkeys are enclosed by quota tion 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 to be entered by the user is displayed in italics Links that you can click are displayed in blue font References to other parts of the
11. Changing the Display Configuration on page 13 Getting Started 1173 9711 02 01 29
12. E 8PSK Predefined settings corresponding to the selected standard are loaded The R amp S FSV K70 should show good measurement results Getting Started 1173 9711 02 01 21 R amp S FSV K70 Measurement Example 2 Burst GSM EDGE Signals Navigating Through the Capture Buffer Spectrum VSA Ref Level 4 00 dBm Std EDGE_8PSK SR 270 833 kHz m elAtt 20 4dB Freq 1 0GHz Cap Len 1500 BURST PATTERN A EYM 1Clrw B Result Summary Carrier Freg Err Gain Imbalance ae Err Start 0 sym Stop 148 sym C Mag CapBuf 1 Clrw D Symbol Table Hexadecimal ne CERA UEENPENE 4 of 7 Start 0 sym Stop 1500 sym 110 aaa at at ol al sta Fig 5 2 R amp S FSV K70 Default display configuration for GSM 8PSK EDGE 7 In screen C you see the currently evaluated burst marked with a green bar To include more bursts in the display you need to increase the capture length a Press the HOME key and then the Settings Overview softkey b Select the I Q Capture block c Increase the Capture Length e g 10000 symbols In the preview area of the dialog box you see that more bursts are now contained in the capture buffer They are all marked with a green bar meaning that they are all evaluated Trace Magttaptut Start L zyr LEETE LOGI Seri Fig 5 3 R amp S FSV K70 Preview of capture buffer 5 3 Navigating Through the Capture Buffer chapter 4 4 Navigating Through the Capture Buffer on page 16 describes how to nav igat
13. Pattern Search You can manually enable disable the burst and pattern search here However based on your signal description this block is automatically configured correctly So there is usually no need to change the configuration manually Result Range The result range specifies how many symbols should be analyzed together For example if the signal is bursted the result range usually coincides with the burst length Demodulation Includes advanced settings regarding the demodulation For example whether a potential I Q offset should be compensated for prior to result calculation Measurement Filter The type of measurement filter is specified here and can be enabled or disabled It limits the measurement signal the reference signal and therefore also the error sig nal in bandwidth By default the R amp S FSV K70 will choose a suitable measurement filter for your selected transmit filter specified in the signal description Evaluation Range The evaluation range is always equal to or smaller than the result range and defines The range over which traces are displayed that do not have a time axis e g polar diagrams The range over which the following parameters are calculated for the result sum mary EVM MER Phase Error Magnitude Error Power See chapter 5 5 Setting the Evaluation Range on page 24 Display Configuration You can select which measurement results should be displayed on the screen see chapter 4 3
14. R amp S FSV K70 Firmware Option Vector Signal Analysis etting Started 1Clw P MagAbs ease Start 0 sym Stop 1500 sym Start Osym r a v 1173 9711 02 01 Config Pattern Burst Pattern Search Range Settings Demod Meas Filter Display Config Stop 200 sym i 15 48 39 Test amp Measurement Getting Started This manual describes the following R amp S FSV options e R amp S FSV K70 1310 8455 02 This manual is applicable for the following analyzer models with firmware version 2 0 and higher e R amp S FSV 3 1307 9002K03 e R amp S FSV 7 1307 9002K07 R amp S FSV 13 1307 9002K13 e R amp S FSV 30 1307 9002K30 e R amp S FSV 40 1307 9002K39 e R amp S FSV 40 1307 9002K40 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 2013 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 Printed in Germany Subject to change Data without tolerance limits is not binding R amp S is a registered trademark of Rohde amp Schwarz GmbH amp Co KG
15. ameters Fig 5 6 Schematic overview of Capture Length Result Range and Evaluation Range To change the evaluated data 1 Start from the configuration described in chapter 5 4 Evaluating the Rising and Falling Edges on page 23 Display the I Q constellation diagram of the signal in screen A In the Display Con fig dialog box activate Screen A and select the Meas amp Ref Signal as the Source and Constellation I Q as the Result Type A clear 8PSK constellation is displayed Getting Started 1173 9711 02 01 25 R amp S FSV K70 Measurement Example 2 Burst GSM EDGE Signals QO Comparing the Measurement Signal to the Reference Signal C Donasi O MeashRel e iM Cire D Mag ba MaastRely C pii Stop 2 505 Shar 26 sym Stop 174 shin Fig 5 7 R amp S FSV K70 Evaluation lines properly adjusted In order to understand the effect of an incorrectly set evaluation range change the evaluation range to include the entire result range a Inthe Settings Overview diagram select the Evaluation Range block b Select the Entire Result Range option Result Range Alignment and Evaluation Range Result Range Evaluation Range Evaluation Range 26 sym 174 sym y Entre Result Range The displayed constellation diagram is no longer clear it contains additional points This is due to the fact that the constellation diagram now displays symbol instants that are beyond the burst
16. cccsseecsseeeeeeeeeeeeeeseeeneesenneesaeeesenees 22 5 4 Evaluating the Rising and Falling Edges ccccssccssseeceseeeeeeeseeseeeeeeeeeesensenenanees 23 5 5 Setting the Evaluation Range sssssssnssnnsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nennen 24 5 6 Comparing the Measurement Signal to the Reference Signal ssesesseeeees 26 6 Brief Overview of the Operating Philosophy cceseeseeeeeeees 28 Getting Started 1173 9711 02 01 3 R amp S FSV K70 Preface Documentation Overview 1 Preface When equipped with application firmware R amp S FSV K70 the analyzer performs vector measurements on digitally modulated signals in the time domain Based on the vector measurements further evaluations e g statistical evaluations can be performed 1 1 Documentation Overview The user documentation for the R amp S FSV K70 application is divided as follows e Getting Started e Operating Manual e Online Help Getting Started With the help of a few sample measurements for the digital GSM and EDGE standards this document provides a quick introduction to typical vector analyzer measurements The individual measurements are in logical order and are meant to familiarize you grad ually with the measurements required of general vector signal analysis Transmitter operation is only described as far as required for performing the measure ments For more details on the measurements
17. documentation are enclosed by quotation marks 1 2 2 Conventions for Procedure Descriptions When describing how to operate the instrument several alternative methods may be available to perform the same task In this case the procedure using the touchscreen is described Any elements that can be activated by touching can also be clicked using an additionally connected mouse The alternative procedure using the keys on the instru ment or the on screen keyboard is only described if it deviates from the standard oper ating procedures The term select may refer to any of the described methods i e using a finger on the touchscreen a mouse pointer in the display or a key on the instrument or on a keyboard Getting Started 1173 9711 02 01 6 R amp S FSV K70 Brief Introduction to Vector Signal Analysis 2 Brief Introduction to Vector Signal Analysis In this chapter we provide a brief overview of vector signal analysis For detailed infor mation see the R amp S FSV K70 Operating manual The goal of vector signal analysis is to determine the quality of the signal that is trans mitted by the device under test DUT by comparing it against an ideal signal The DUT is usually connected with the analyzer via a cable The key task of the analyzer is to determine how the ideal signal would look Hence the analyzer aims to reconstruct the ideal signal from the measured signal that is transmitted by the DUT This ideal signal is commo
18. e modulation a Press the DIAGRAM key b Select the first block Baseband A in the settings overview and press ENTER Getting Started 1173 9711 02 01 9 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Transmitter Settings c Select Custom Digital Mod Custom Digital Modulation SEx State Set to Default Save Recall Data Source Data Source PRBS PRBS Type PRBS a v Select Control List None List Management Set acc to standard user amp SaveRecall User Symbol Rate 1000 000 000 syns Coding OFF ydulation sd Root Cosine Roll Off Factor TSS Oversampling 7 Auto Po R More Power Ramp Control Off Cosine 1 00 sym Trigger Market Auto a Clock Internal Fig 4 1 R amp S SMU Custom Digital Modulation Dialog d Under Modulation Type select PSK gt QPSK 5 Inthe Custom Digital Modulation dialog box a Enter the Symbol Rate 1 MHz b Select the Filter Root Cosine c Enter the Roll Off Factor 0 35 d Toggle the State to On at the top of the dialog box to switch modulation on 6 Press the RF ON OFF key to switch the RF transmission on Getting Started 1173 9711 02 01 10 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Analyzer Settings 4 2 Analyzer Settings This section helps you get your first valid measurement It starts with step by step ins
19. e through the capture buffer for a continuous signal This navigation feature is espe cially important for bursted signals Therefore we give here a further navigation example for the GSM EDGE signal 1 In order to see more details in the capture buffer close Screen D Getting Started 1173 9711 02 01 22 R amp S FSV K70 Measurement Example 2 Burst GSM EDGE Signals SSS UMMM Evaluating the Rising and Falling Edges a Press the Display Config softkey or the Display Configuration block in the Settings Overview diagram b Deactivate Screen D 2 Press the RUN SINGLE key 3 Inthe EVM vs Time display Screen A add a maximum hold trace by pressing the TRACE key see chapter 4 5 Averaging Several Evaluations on page 17 4 Re evaluate the whole capture buffer by pressing the SWEEP key and then the Refresh softkey 5 Use the Select Result Rng softkey to navigate through your capture buffer Thus you can determine which peak was caused by which burst Spectrum WA Ref Level 25 00 dim Std EDGE BPSK SR 270 033 kHz e Att 10 dB Freg 1 0GHz Res Len 14B KE LANAK Ll SGL Stat Count amp BURST PATTERN AEVM e 1 Ory e2 Mak B Result Summary Meam Peak Umit Single 2s 0 26 Sweep 0 20 l Sweep ee dag continue l j Single Select Result Range Sweep i l LUG T d 5 Lae ioe 1 j Offs 57 59 65 52 dB RE i Gain Imbalance n 0 04 AP Jabot
20. ection summarizes the necessary transmitter settings It contains a list of the parameters and step by step instructions for the R amp S SMU If you are interested in a more detailed description or background information refer to the user manual of the R amp S SMU which can be downloaded from the Rohde amp Schwarz website www rohde schwarz com downloads manuals smu200A html Standard GSM EDGE Burst with normal symbol rate To define the settings for the R amp S SMU 1 Press the PRESET key to start from a defined state 2 Press the FREQ key and enter 7 GHz 3 Press the LEVEL key and enter 0 dBm 4 To define the standard a Press the DIAGRAM key b Select the first block Baseband A in the settings overview and press ENTER c Select GSM EDGE Getting Started 1173 9711 02 01 19 R amp S FSV K70 Measurement Example 2 Burst GSM EDGE Signals Transmitter Settings d Highlight the first slot in the frame diagram and press ENTER GSM EDGE B mxi y Set To Default Save Recall Data List Management Sequence Mode Framed Single Symbol Rate Mode Normal Symbol Rate Modulation Filter Power Ramp Slot Attenuations Trigger Marker Clock Frame Select Slot To Configure Fig 5 1 R amp S SMU GSM EDGE Frame Configuration Dialog e Select the Burst Type Normal 8PSK EDGE z GSM EDGE B Burst Slott g Ssave Recall Slots Slot Level Ful Slo
21. ignal The avail able choices depend on the selected source For example an eye diagram of the inphase component can only be selected if the source for the current screen is Meas amp Ref Signal e Result type transformation For certain result types it is not only possible to see the common over time repre sentation of the measurement but also the spectrum or the statistics in form of a histogram Furthermore it is possible to specify how many points i e samples per symbol should be displayed For example it might make sense for certain measure ment results to only display the symbol instants In this case the parameter Display Points Sym should be set to 1 To customize your own display configuration 1 Select the tab for the screen you want to configure e g Screen A 2 Close screen A by disabling Screen A active highlighted in figure 4 5 and close the dialog You will now see only three screens in your display layout Getting Started 1173 9711 02 01 15 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal OTTO XOX Navigating Through the Capture Buffer 3 Enable screen A again to take a look at the eye diagram of the inphase component of the measurement signal Select e Source Meas amp Ref e Result Type Eye Diagram Real 1 4 Close the dialog to take a look at your new display configuration 5 Change the Result Type of screen A back to EVM Source Error Vector Result
22. isplay using the icon in the toolbar see the dotted rectangle in figure 5 9 Spectrum VSA Ref Level 4 00 dBm Std EDGE_SPSK SR 270 833 kHz Att 24 dB Freq 1 0 GHz Res Len 200 BURST PATTERN D MagAbs Meas Ref 1M Clrw 2R Clrw 0 cam 10d Em 20 dBm 30 dBm 40 dBm 50 dBm 60 d m Oo dBm 80 dBm 90 dBm start 26 sym Stop 174 sym Fig 5 9 R amp S FSV K70 Zooming Now you can compare the measured and the ideal reference signal gt Press the Toolbar icon to the right of the tabs in the display to toggle the toolbar on or off Alternatively 1 Press the SETUP key 2 Press the Display Setup softkey 3 Press the Tool Bar State On Off softkey or press the DISPLAY key and in the Display Settings dialog box select Tool Bar State On The toolbar is displayed at the top of the screen Getting Started 1173 9711 02 01 27 R amp S FSV K70 Brief Overview of the Operating Philosophy 6 Brief Overview of the Operating Philosophy Now that you have completed the two measurement examples we would like to introduce the operating philosophy of the R amp S FSV K70 For a detailed description of functions and settings see the R amp S FSV K70 Operating Manual For information on general operation of the analyzer see the R amp S FSV base unit operating manual The main principle of the R amp S FSV K70 application is that you do not need to worry about measurement settings As already explained in Brief
23. lyzer Settings c Inthe Transmit Filter section select RRC as Type and enter the Alpha BT value 0 35 In the preview area of the dialog you should then see a non distorted QPSK constellation diagram as shown in figure 4 2 2 Modulation amp Signal Description Modulation PS Modulation Settings Type SK Order QPSK Mapping WCDMA Symbol Rate 1 0 MHz Transmit Filter Type RRC Alpha BT 0 35 Trace Constellation Q Meas amp Ref stop 4 608 Fig 4 2 R amp S FSV K70 Modulation Dialog for Measurement Example 1 7 Close all open dialog boxes By default four measurement screens showing different measurement results are displayed Getting Started 1173 9711 02 01 12 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Changing the Display Configuration Spectrum VSA Ref Level 4 00 dBm Mod QPSK SR 1 0 MHz m el tt 20 4dB Freq 1 0GHz ResLen 800 A Const I Q Meas amp Ref 1M Clrw B Result Summary Phase Err RMS Carrier Freq Err Gain Imbalance Quadrature Err Amplitude Droop Start 2 43 Stop 2 43 C Mag CapBuf D Symbol Table Hexadecimal a A E ee ee T 2 of 1 2 1 2 o 2 1 3 amp 40 dBm a 10 20 30 40l 60 dBm 50 2 at eee 60 gt o oj 2 2 o 2 3l 80 dBm of 2 3 a 2 of af of 2 80 o 2 2 3 oj 2 2 3l 90 100 110 100 dBm a3 at ala if af af ol af o Start 0 sym Stop 8000 sym Fig 4 3 R amp S
24. nly referred to as the reference signal while the signal from the DUT is called the measurement signal After the extraction of the reference signal the measurement signal and the reference signal are compared by the vector signal analysis software and the results of this com parison are displayed on the analyzer screen The most common vector signal analysis measurement is the EVM Error Vector Mag nitude measurement Here the complex baseband reference signal is subtracted from the complex baseband measurement signal The magnitude of this error vector repre sents the EVM value The EVM has the advantage that it summarizes all potential errors and distortions in one single value If the EVM value is low the signal quality of the DUT is high Analyzer Device Under Test DUT Extraction of Ideal Signal Comparison Result Displays Fig 2 1 Simplified schema of vector signal analysis Getting Started 1173 9711 02 01 7 R amp S FSV K70 Connecting the Transmitter and Analyzer 3 Connecting the Transmitter and Analyzer In order to perform measurements with the R amp S FSV K70 you require a test transmitter to emulate a DUT For measurement example 2 see chapter 5 Measurement Example 2 Burst GSM EDGE Signals on page 19 the test transmitter needs to be GSM compatible It is recommended that you use an R amp S SMU order number 1141 2005 02 with the digital standard option GSM EDGE o
25. r display the absolute magnitude val ues of the measured signal in screen D In the Display Config dialog box activate screen D and select the Meas amp Ref Signal as the Source and Magnitude as the Result Type 3 Press RUN SINGLE The rising and falling edges of the burst in the selected result range are displayed in screen D You could now add an average trace to evaluate the rising and falling edges further Spectrum YSA Ref Level 4 00 dBm Std EDGE_ PSK SAR 270 833 kHz Att 24 dE Freg 1 0 GHz Res Len 200 SGL Stat Count 3 BURST PATTERN B Result Summary U 25 H ja 0 24 Phase Err RMS Peak Carrier Freq Err 994 0 999 95 Q Offset 51 09 Gain Imbalance 0 01 Quadrature Err 0 13 g Amplitude Droop EAS i 2 Conti 7 15 2 04 dBm J Pattern a a er Ps iin Lara i A a Start 26 sym Stop 174 sym C Mag CapBuft 1 irw D MagAbs Meas amp Ref y Burst i Pi i Ln L i Eiir E e i kaa Jy Pattern Search 20 demi Range Settings 40 gam i i i Demod Meas Filter BU obi 50 dEr Display Config Miah id a Start O sym j Stop 10000 sym Start 26 sym Stop 174 sym OF 10 20 10 itak Fig 5 5 R amp S FSV K70 Result range that exceeds the burst length 5 5 Setting the Evaluation Range The R amp S FSV K70 contains three major ranges that need to be set by the user e Capture Buffer Here you specify how many data points should be captured for your signal
26. rder number 1160 7609 02 Connect the RF output of the R amp S SMU with the RF input of the R amp S FSV RF Output RF Input Fig 3 1 Connection to a test transmitter for example R amp S SMU Getting Started 1173 9711 02 01 8 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Transmitter Settings 4 Measurement Example 1 Continuous QPSK Signal In this measurement example a continuous QPSK Quadrature Phase Shift Keying sig nal will be measured and evaluated QPSK is used in several standards such as DVB 2 APCO25 WCDMA CDMA2000 etc For the description characterization of a con tinuous QPSK signal the following parameters are the most important e Carrier Frequency e Level e Symbol Rate e Transmit Filter 4 1 Transmitter Settings This section summarizes the necessary transmitter settings It contains a list of the parameters and step by step instructions for the R amp S SMU If you are interested in a more detailed description or background information refer to the user manual of the R amp S SMU which can be downloaded from the Rohde amp Schwarz website www rohde schwarz com downloads manuals smu200A html Modulation QPSK Symbol Rate 1 Msym s Root Raised Cosine with Roll Off 0 35 To define the settings for the R amp S SMU 1 Press the PRESET key to start from a defined state 2 Press the FREQ key and enter 7 GHz 3 Press the LEVEL key and enter 0 dBm 4 To define th
27. s amp Ref Fig 4 4 R amp S FSV Predefined display configurations In our example we know that we are measuring a QPSK modulation 1 Select PSK QAM typical configuration and then Apply 2 Close the dialog box The display is then configured as described in the dialog box Customized Display Configuration The tabs for customized display configuration provide several possibilities Getting Started 1173 9711 02 01 14 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Changing the Display Configuration Display Configuration x Screen A Source for Screen A Capture Buffer Error Vector Meas amp Ref Signal Modulation Errors Symbols Modulation Accuracy Result type for Screen A Magnitude Absolute Magnitude Relative Phase Wrap Phase Unwrap Frequency Absolute Frequency Relative to SR Real Imag 1 Q Eye Diagram Real 1 Eye Diagram Imag Q Eve Diagram Frequency Constellation 1 Q Vector I Q Constellation Frequency Vector Frequency Result Type Transformation for Screen A Normal Spectrum Statistics Display Points Sym wf auto Fig 4 5 R amp S FSV K70 Customized display configuration e Source Here you can choose whether you would like to see results from the capture buffer the measurement signal the error vector etc e Result type Here you can specify the way you want to look at the Source For example select Magnitude Absolute to see the magnitude of your measurement s
28. t Attenuation o o dB A1 Multislot Configuration Number Of Slots 4 Burst Fields 111111111 PRBS g Training Sequence TSC Tsc 0 User TSC 11 1111 0 Guard 111 1111 1111 1111 1111 1111 1111 Slot Marker Definition f Close the GSM EDGE Burst Slot0 dialog box 5 Toggle the State to On at the top of the GSM EDGE dialog box to switch the modulation on Getting Started 1173 9711 02 01 R amp S FSV K70 5 2 Measurement Example 2 Burst GSM EDGE Signals Analyzer Settings 6 Press the RF ON OFF key to switch the RF transmission on El csmence a Analyzer Settings This section helps you get your first valid measurement with a bursted signal It starts with step by step instructions and continues with a more detailed description of further functionality Note that the settings are described for firmware version 1 60 Small differ ences in labels or titles may be found in other versions Standard GSM 8PSK EDGE To define the settings on the R amp S FSV 1 Press the PRESET key to start from a defined state 2 Press the FREQ key and enter 7 GHz 3 Press the AMPT key then the Ref Level softkey and enter 4 dBm 4 Start the R amp S FSV K70 option by pressing the MODE key and then selecting the VSA vector signal analysis softkey on In the main VSA menu select the Digital Standards softkey 6 From the file selection list select the GSM folder and then the file EDG
29. the TRACE key and then either using the Trace 2 3 softkeys or the Trace Wizard Set the second trace to Average and the third trace to Max Hold Note that the configured traces appear in the screen title Getting Started 1173 9711 02 01 17 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Averaging Several Evaluations Start 0 sym stop 600 sym Fig 4 6 R amp S FSV Several traces in one screen 4 Press RUN SINGLE again The current capture buffer is evaluated for this trace setup In the channel information bar you can see the number of completed evaluations Stat Count Spectrum VSA Ref Level 4 00 dBm Mod is Att 24 dE Freq 1 0GHz Res Len SGL Stat Count 10 A EVM b 1 Clrw 5 To change the number of evaluations press the SWEEP key and select Statistic Count Select Manual and enter the desired number of evaluations e g 12 When you press RUN SINGLE the R amp S FSV K70 will capture I Q data until 12 evaluations are completed Getting Started 1173 9711 02 01 18 R amp S FSV K70 D 5 1 Measurement Example 2 Burst GSM EDGE Signals Transmitter Settings Measurement Example 2 Burst GSM EDGE Signals In this measurement example a bursted GSM EDGE signal will be measured and eval uated The goal of this section is to familiarize you with the R amp S FSV K70 features that are relevant specifically for the analysis of bursted signals Transmitter Settings This s
30. truc tions and continues with a more detailed description of further functionality Note that the settings are described for firmware version 1 60 Small differences in labels or titles may be found in other versions Modulation QPSK Tx Filter Root Raised Cosine with Alpha BT 0 35 To define the settings on the R amp S FSV 1 Press the PRESET key to start from a defined state 2 Press the FREQ key and enter 7 GHz 3 Press the AMPT key then the Ref Level softkey and enter 4 dBm This corresponds approximately to the peak envelope power of the signal 4 Start the R amp S FSV K70 option by pressing the MODE key and then selecting the VSA vector signal analysis softkey 5 Inthe main VSA menu select the Settings Overview softkey This overview dialog serves as a guide to set up the R amp S FSV K70 option It is described in more detail in Settings Overview on page 29 6 Select the first block in the overview diagram Modulation Signal Description a Inthe Modulation Settings section ensure that the Type is PSK and that the Order is QPSK The Mapping defines the mapping of the bits to the QPSK symbols It is relevant if you are interested in a bit stream measurement and does not affect the other measurement results Hence you do not need to change it here b Enter the Symbol Rate 7 MHz Getting Started 1173 9711 02 01 11 R amp S FSV K70 Measurement Example 1 Continuous QPSK Signal Ana
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