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R&S®FSQ-K70, R&S®FSU and R&S®FSMR-B73 Vector Signal Analysis
User Manual
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User Manual
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Rohde&Schwarz R&S®FSQ-K70, R&S®FSU and R&S®FSMR-B73 Vector Signal Analysis User Manual

PAD-T-M: 3574.3259.02/01.00/CI/1/EN
R&S®FSQ-K70/FSMR/FSU-B73 Vector Signal Analysis
Software Manual
Software Manual
Test and Measurement
1161.8073.42 – 13
© 2014 Rohde & Schwarz GmbH & Co. KG Muehldorfstr. 15, 81671 Munich, Germany Phone: +49 89 41 29 - 0 Fax: +49 89 41 29 12 164 E-mail: info@rohde-schwarz.com Internet: http://www.rohde-schwarz.com Subject to change – Data without tolerance limits is not binding. R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG. Trade names are trademarks of the owners.
The following abbreviations are used throughout this manual: R&S®FSQ-K70/FSMR/FSU-B73 is abbreviated as R&S FSQ-K70/FSMR/FSU-B73
R&S FSQ-K70/FSMR/FSU-B73 Contents
Software Manual 1161.8073.42 - 13 3

Contents

1 Vector Signal Analysis ....................................................................... 9
1.1 Enabling the Firmware Option .................................................................................... 9
1.2 Test Setup for Measurement on Base Stations and Power Amplifiers ................10
1.2.1 Precautions ..................................................................................................................10
1.2.2 Standard Test Setup ....................................................................................................10
1.3 Calling and Exiting the Option - VSA Softkey .........................................................11
1.3.1 Calling the Option - VSA Softkey .................................................................................11
1.3.2 Exiting the Option - VSA Softkey .................................................................................11
1.3.3 Return to VSA Menu (Home VSA Hotkey) ..................................................................11
1.3.4 Overview ......................................................................................................................12
2 First Measurements - Getting Started ............................................. 13
2.1 Interconnecting Transmitter and Analyzer .............................................................13
2.2 Basic Settings of Test Transmitter ..........................................................................14
2.3 Switching On the R&S FSQ-K70/FSMR-B73/FSU-B73 Option ...............................14
2.4 Basic Analyzer settings for EDGE Measurements .................................................15
2.5 Measurement 1: Demodulation of a Single EDGE Burst .......................................15
2.6 Measurement 2: Selection of a Specific Slot with Trigger Offset .........................19
2.7 Measurement 3: Setting the Burst Search Parameters (LEVEL) ..........................22
2.8 Measurement 4: Suppression of Incorrect Measurements ...................................24
2.9 Measurement 5: Evaluation Lines ............................................................................26
3 Brief Description of Vector Signal Analysis (Function) ................. 29
3.1 Block Diagram of Digital Signal Processing Hardware .........................................29
3.1.1 Description of Block Diagram ......................................................................................29
3.1.2 Bandwidths for Signal Processing ...............................................................................30
3.2 Symbol Mapping ........................................................................................................44
3.3 Demodulation and Algorithms .................................................................................66
3.3.1 Burst Search ................................................................................................................69
3.3.2 Demodulator 1 .............................................................................................................71
3.3.3 Demodulator 2 .............................................................................................................73
3.3.4 Matching ......................................................................................................................74
3.3.5 Pattern Search .............................................................................................................77
3.3.6 Result & Error Calculation, Display ..............................................................................79
R&S FSQ-K70/FSMR/FSU-B73 Contents
Software Manual 1161.8073.42 - 13 4
3.3.7 Differences between Modulation Types ......................................................................80
3.4 Vector and Scalar Modulation Errors ......................................................................81
3.4.1 Error Model of Transmitter ...........................................................................................81
3.4.2 Modulation Error (PSK, MSK, QAM, VSB) ..................................................................81
3.4.3 Modulation Error (FSK) ................................................................................................91
4 Operation and Menu Overview ................................ ........................ 93
4.1 Operation ....................................................................................................................93
4.2 Special Features/Differences from the Basic Instrument ......................................93
4.2.1 Display of States Within Softkeys ................................................................................93
4.2.2 Display of Setting Parameters Within Softkeys ...........................................................94
4.2.3 Measurement Window .................................................................................................96
4.3 Menu Overview ...........................................................................................................98
4.3.1 Hotkeys ........................................................................................................................98
4.3.2 Softkeys .......................................................................................................................99
5 Instrument Settings and Measurements ....................................... 104
5.1 Resetting the Option - PRESET VSA Hotkey ........................................................104
5.2 Overview of Current Settings - SETTINGS Hotkey ...............................................104
5.3 Configuration of Measurements - HOME VSA Hotkey .........................................105
5.4 Measurements on Dig. Standards - DIG. STANDARD Softkey ............................106
5.4.1 Predefined Standards and Standard Groups ............................................................106
5.4.2 List of Predefined Standards and Standard Groups ..................................................108
5.4.3 DIGITAL STANDARD Menu ......................................................................................111
5.5 BURST& PATTERN Softkey ....................................................................................116
5.5.1 Burst and Search Parameters ...................................................................................116
5.5.2 Multiple Evaluation of a Captured Data Record (MULTI) ..........................................117
5.5.3 Burst and Search Parameters for Predefined Standards ..........................................122
5.5.4 Pattern and Pattern Lists ...........................................................................................123
5.5.5 BURST& PATTERN Menu ........................................................................................125
5.6 Setting Parameters - MODULATION SETTINGS Softkey .....................................136
5.7 Setting Demodulation - DEMOD SETTINGS Softkey ............................................142
5.7.2 Evaluation Lines / Limiting the Measurement Range ................................................145
5.7.3 Record Buffer, Demodulation Range and Display Range .........................................147
5.8 Display of Measurement Results ...........................................................................149
5.8.1 Spectral Displays .......................................................................................................149
5.8.2 Statistical Displays .....................................................................................................150
5.8.3 MEAS RESULT Softkey ............................................................................................152
R&S FSQ-K70/FSMR/FSU-B73 Contents
Software Manual 1161.8073.42 - 13 5
5.8.4 Selection of Displayed Measurement and Reference Signal - MEAS SIGNAL / REF
SIGNAL Softkey .........................................................................................................159
5.8.5 Selection of Error Display - ERROR SIGNAL Softkey ...............................................172
5.8.6 Selection of the Raw Signal - CAPTURE BUFFER Softkey ......................................188
5.8.7 Selection of Adaptive Equalizer Display - EQUALIZER Softkey ...............................198
5.9 Positioning of Display on Screen - FIT TRACE Softkey ......................................206
5.9.1 Scaling of Time Axis in Symbols ................................................................................209
5.9.2 FIT TRACE Menu ......................................................................................................210
5.10 Multiple Evaluation and Section Displays - ZOOM Softkey.................................211
5.11 Setting of Span - RANGE Softkey ..........................................................................212
5.11.1 Automatic Setting of Reference Level - ADJUST LVL Softkey .................................214
5.11.2 Restoring of Factory Settings - FACTORY DEFAULTS Softkey ...............................214
5.11.3 Importing Stand., Mappings, Pattern and Filter - IMPORT Softkey ...........................215
5.11.4 Export of Stand., Mappings, Pattern and Filter - EXPORT Softkey ..........................218
5.12 Overview of Other Menus .......................................................................................221
5.12.1 Default Settings - PRESET Key .................................................................................221
5.12.2 System Error Correction - CAL Key ...........................................................................221
5.12.3 General Instrument Settings - SETUP Key ...............................................................221
5.12.4 Documentation of Results - HCOPY Key ..................................................................223
5.12.5 Frequency Settings - FREQ Key ...............................................................................223
5.12.6 Span ...........................................................................................................................224
5.12.7 Level Settings - AMPT Key ........................................................................................224
5.12.8 Selection of Units for Display - DISPLAY UNIT Key ..................................................224
5.12.9 Setting of Bandwidth for Analog IF Filter - BW Key ...................................................225
5.12.10 Sweep Settings - Sweep Key ....................................................................................225
5.12.11 MEAS Key ..................................................................................................................226
5.12.12 Trigger Settings - TRIGGER Key ...............................................................................226
5.12.13 Trace Functions - TRACE Key ..................................................................................227
5.12.14 Limit Lines Settings - LINES Key ...............................................................................231
5.12.15 Screen Configuration - DISP Key ..............................................................................232
5.12.16 File Management - FILE Key .....................................................................................232
5.12.17 Marker Settings - MARKER Key ................................................................................233
5.12.18 Marker Settings (Marker to) - MKR -> Key ................................................................233
5.12.19 Marker Functions - MKR FCTN Key ..........................................................................233
5.13 Troubleshooting .......................................................................................................239
5.13.1 Different Symbol Rate Setting in Transmitter and Analyzer ......................................240
5.13.2 Different Filter Settings in Transmitter and Analyzer .................................................242
5.13.3 Incorrect Modulation of Analyzer ...............................................................................244
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Software Manual 1161.8073.42 - 13 6
5.13.4Overdrive Condition of the Analyzer ...............................................................................................246
6 Remote: Control Commands ......................................................... 248
6.1 CALCulate - Subsystem ..........................................................................................248
6.1.1 CALCulate:DDEM - Subsystem .................................................................................249
6.1.2 CALCulate:FEED - Subsystem ..................................................................................250
6.1.3 CALCulate:FORMat - Subsystem ..............................................................................251
6.1.4 CALCulate:ELIN - Subsystem ...................................................................................253
6.1.5 CALCulate:MARKer:FUNCtion Subsystem ...............................................................254
6.1.6 CALCulate:STATistics - Subsystem ..........................................................................282
6.1.7 CALCulate:TRACe - Subsystem ................................................................................283
6.1.8 CALCulate:UNIT - Subsystem ...................................................................................285
6.2 DISPlay - Subsystem ...............................................................................................286
6.3 FORMat -Subsystem ................................................................................................291
6.4 INSTrument - Subsystem ........................................................................................294
6.5 MMEMory - Subsystem ...........................................................................................295
6.6 SENSe - Subsystem .................................................................................................297
6.6.1 SENSe:DDEMod-Subsystem ....................................................................................297
6.6.2 SENSe:FREQuency - Subsystem .............................................................................335
6.7 TRACe – Subsystem ................................................................................................335
6.8 TRIGger - Subsystem ..............................................................................................338
6.9 Table of Softkeys Assigned to IEC/IEEE Bus Commands ..................................339
6.9.1 Hotkey VSA ................................................................................................................339
6.9.2 Hotkeys of Option ......................................................................................................339
6.9.3 FREQ Key ..................................................................................................................352
6.9.4 SPAN Key ..................................................................................................................352
6.9.5 AMPT Key ..................................................................................................................352
6.9.6 MKR Key ....................................................................................................................354
6.9.7 MKR -> Key ...............................................................................................................354
6.9.8 MKR FCTN Key .........................................................................................................355
6.9.9 BW Key ......................................................................................................................356
6.9.10 SWEEP Key ...............................................................................................................356
6.9.11 MEAS Key - not available ..........................................................................................357
6.9.12 TRIG Key ...................................................................................................................357
6.9.13 TRACE Key ................................................................................................................357
6.9.14 LINES Key .................................................................................................................358
6.9.15 DISP Key ...................................................................................................................359
6.9.16 FILE Key ....................................................................................................................360
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Software Manual 1161.8073.42 - 13 7
6.9.17 CAL Key .....................................................................................................................361
6.9.18 SETUP Key ................................................................................................................362
6.9.19 HCOPY Key ...............................................................................................................364
6.9.20 Hotkey Bar .................................................................................................................364
6.10 STATus-QUEStionable:SYNC Register .................................................................365
6.11 STATus-QUEStionable:POWer Register ...............................................................365
7 Programming Examples ................................................................. 366
7.1 Performing a Measurement with OPC Synchronization ......................................366
7.2 Creating a Search Pattern .......................................................................................367
8 Checking the Rated Specifications ............................................... 369
8.1 Required Test Equipment and Accessories .........................................................369
8.2 Test Sequence ..........................................................................................................369
9 Utilities /External Programs ........................................................... 371
9.1 Mapping Editor (MAPWIZ) .......................................................................................371
9.2 Filter Tool (FILTWIZ) ................................................................................................372
10 Glossary and Formulare ................................................................. 373
10.1 Trace-based Evaluations ........................................................................................373
10.2 Summary - Evaluations ...........................................................................................374
10.3 Statistical Evaluations .............................................................................................376
10.4 Trace Averaging and Marker Functions ................................................................376
10.5 Averaging RMS Quantities ......................................................................................377
10.6 Analytically Calculated Filters ................................................................................377
10.7 Standard-Specific Filters ........................................................................................378
10.8 Analytically Calculated Filters ................................................................................379
10.9 Standard-Specific Filters ........................................................................................380
10.10 Abbreviations Used .................................................................................................381
11 Index ................................................................................................ 383
R&S FSQ-K70/FSMR/FSU-B73 Vector Signal Analysis
Software Manual 1161.8073.42 - 13 9

1 Vector Signal Analysis

VSA
SPECTRUM
SCREEN B
When equipped with application firmware R&S FSQ-K70 or the VSA Extension R&S FSMR/FSU-B73, the Analyzer R&S FSQ/FSU/FSUP or the Measuring Receiver R&S FSMR performs vector measurements on digitally modulated signals in the time domain. Based on the vector measurements, further evaluations, e.g. statistical evaluations or distortion measurements can be performed.

1.1 Enabling the Firmware Option

Firmware option R&S FSQ-K70/FSMR-B73/FSU-B73 is enabled by entering a keyword in the SETUP GENERAL SETUP menu. The keyword is supplied with the option. If the option is factory-installed, it is already enabled.

GENERAL SETUP Menu:

OPTIONS
The OPTIONS softkey opens a submenu where the keywords for new firmware options (application firmware modules) can be entered. Available options are listed in a table displayed when the submenu is opened.
INSTALL OPTION
The INSTALL OPTION softkey activates the keyword entry field of a firmware option. One or more keywords can be entered in the entry field. If a valid keyword is entered,
OPTION KEY OK is displayed and the option is added to the FIRMWARE OPTIONS table.
If an invalid keyword is entered, OPTION KEY INVALID is displayed. After installation of the option, VSA ( = vector signal analysis) is displayed in the
hotkey bar of the R&S FSQ/FSMR/FSU. The position of the VSA hotkey may vary depending on the type and number of options installed.
Fig. 1 Hotkey bar of basic unit with option R&S FSQ-K70/FSMR-B73/FSU-B73 installed.
R&S FSQ-K70/FSMR/FSU-B73 Vector Signal Analysis
Software Manual 1161.8073.42 - 13 10
1.2 Test Setup for Measurement on Base Stations and Power
Danger of electric shock or from radiation
The relevant safety standards (e.g. EN 60215 and IEC215) must be complied with when operating transmitters and amplifier output stages.
Destruction of the input mixer When transmitters or transmitter output stages with an output power of more than 30
dBm are connected, a suitable power attenuator or power coupler must be used to prevent the analyzer input stages from being damaged.
For R&S FSQ/FSMR/FSU devices with an upper frequency limit of 26.5 GHz or less, the RF input is AC-coupled with switchable AC/DC coupling. For all other R&S FSQ/FSMR/FSU devices (upper frequency limit > 26.5 GHz), the RF input is DC­coupled.
For AC-coupling, a DC input voltage of 50 V must never be exceeded. For DC­coupling, DC voltage must not be applied at the input.
In both cases, noncompliance will destroy the input mixers.
Amplifiers
Special precautions are to be observed when measurements on power amplifiers and mobile radio base stations are performed.

1.2.1 Precautions

1.2.2 Standard Test Setup

Fig. 2 Connection to RF output of a base station (for example R&S FSQ)
R&S FSQ-K70/FSMR/FSU-B73 Vector Signal Analysis
Software Manual 1161.8073.42 - 13 11

1.3 Calling and Exiting the Option - VSA Softkey

EXIT VSA
DEFAULTS
SCREEN B
SETTINGS
HOME VSA
SCREEN C

1.3.1 Calling the Option - VSA Softkey

Call the R&S FSQ-K70/FSMR-B73/FSU-B73 option by pressing the VSA hotkey. After activation, the labels in the hotkey bar and the contents of the menus are adapted
to the functions of the VSA option. The menus of the option are described in Chapter 5, "Instrument Settings and Measurements".
Remote: INST:SEL DDEM
Fig. 3 Hotkey bar when option R&S FSQ-K70/FSMR-B73/FSU-B73 is active

1.3.2 Exiting the Option - VSA Softkey

To exit the R&S FSQ-K70/FSMR-B73/FSU-B73 option, press the EXIT VSA hotkey. When the option is closed, the hotkey bar and the menus of the basic unit are restored. When the option is closed, the hotkey bar and the menus of the basic unit are restored.
Remote: INST:SEL SAN

1.3.3 Return to VSA Menu (Home VSA Hotkey)

HOME VSA
Pressing HOME VSA in any position of the VSA menu branches to the VSA menu. This function should be used particularly after frequency, level and trigger settings,
because automatic return to the VSA menu is not possible in this case.
R&S FSQ-K70/FSMR/FSU-B73 Vector Signal Analysis
Software Manual 1161.8073.42 - 13 12

1.3.4 Overview

Analyzer mode VSA
SPECTRUM
VSA
EXIT VSA
Starting the
application
Exiting the
application
Return to main menu
of R&S FSK-K70
VSA mode
(R&S FSQ-K70/FSMR/FSU-B73)
HOME VSAEXIT VSA
Key
HOME VSA
Operation within
the application
The following functions are shown by the diagram below:
● Starting R&S FSQ-K70/FSMR-B73/FSU-B73 in the spectrum analyzer mode
● Navigation within the application
● Exiting the application
The position of the VSA hotkey may vary depending on the number of activated options.
Fig. 4 Overview: calling and ex iting option FSQ-K70/FSMR/FSU-B73
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 13

2 First Measurements - Getting Started

With the aid of a few sample measurements for the digital GSM and EDGE standards, this chapter gives a quick introduction to typical vector analyzer measurements. The individual measurements are in logical order and should familiarize the user gradually with the measurements required of general vector signal analysis. To benefit from this didactics, use the „Continuous – Facing“ view for the display on the screen. The following equipment is required in addition to the Analyzer R&S FSQ/FSU/FSUP/FSG or Measuring Receiver R&S FSMR with option R&S FSQ­K70/FSMR-B73/FSU-B73:
● 1 test transmitter (GSM-compatible), preferably R&S SMIQ (1125.5555.03)
● 1 ParData Adapter R&S SMIQ-Z5 for R&S SMIQ (1104.8555.02)
● 1 RF cable with 2 male N connectors
● 2 RF cable with 2 male BNC connectors
● 2 power cables
Transmitter operation is only described as far as required for performing the measurements. For more details on the measurements, refer to the test transmitter documentation.

2.1 Interconnecting Transmitter and Analyzer

Fig. 5 Connection to a test transmitter (for example R&S FSQ)
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 14

2.2 Basic Settings of Test Transmitter

Parameter
Setting
Level
0 dBm
Frequency
2 GHz
Setting
Operatingsequence SMIQ
Grundeinstellung für GSM / EDGE Softkey Digital Standard
Digital Standard GSM/EDGE State ON
<Select> <Select> <Select> <Select> <Return>
Setting
Measureme nt
EDGE Single Burst
1
Save/Recall Frame Get predefined Frame EDGE0
<Select> <Select> <Select> <Return> <Return>
EDGE Full Frame
2,3,5,6,7
Save/Recall Frame Get predefined Frame EDGE_ALL
<Select> <Select> <Select> <Return> <Return>
GSM/EDGE Mixed Frame
4
Save/Recall Frame Get predefined Frame GSM_EDGE
<Select> <Select> <Select> <Return> <Return>
GSM Full Frame
4
Save/Recall Frame Get predefined Frame GSM_ALL
<Select> <Select> <Select> <Return> <Return>
EDGE Slot Att. (20 dB / slot 1..7)
Slot Attenuation 20 Select Slot Slot 1..7 Slot Level ATTEN
<Select> <dB> <Select> <mark with rotary knob> <Select> <Select> <select with rotary knob> <Select> <Return> <Return>
The following frequency and level settings are made on the test transmitter for the measurements below:
Table 1 Basic settings of test transmitter for first measurements
Transmitter settings for the various measurements are listed in the table below:
Table 2 Transmitter settings for various measurements

2.3 Switching On the R&S FSQ-K70/FSMR-B73/FSU-B73 Option

Hotkeys VSA Press the VSA hotkey to call the R&S FSQ-K70/FSMR-B73/FSU-B73 option. After activation, the labels in the hotkey bar and the contents of the menus are adapted
to the functions of the VSA option. The menus of the option are described in Chapter 5, "Instrument Settings and Measurements"
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 15

2.4 Basic Analyzer settings for EDGE Measurements

Parameter
Setting
Frequency
2 GHz
Reference level
+6 dBm
Parameter
Setting
Digital standard
EDGE_NB
Sweep
CONTINUOUS
Burst search
ON
Pattern search
ON
Pattern
EDGE_TSC0
Display mode
Screen A: EVM Screen B: Symbols & Modulation Accuracy
In the default setting after PRESET, the R&S FSQ/FSMR/FSU is in the analyzer mode. In this mode the following settings must be made:
Table 3 Basic instrument settings
The following settings of the R&S FSQ-K70/FSMR-B73/FSU-B73 option are only enabled after the vector signal analyzer mode is set and the digital standard EDGE_NB (normal burst) is selected.
Table 4 Basic setting for vector signal analysis measurements

2.5 Measurement 1: Demodulation of a Single EDGE Burst

Objective of the measurement:
● Demodulation of a single EDGE burst and result display
● Switchover of result display to I/Q VECTOR
● Disabling the measurement filter and measuring the raw transmitter signal
Instrument settings:
► Transmitter: GSM default setting
EDGE Single Burst
► Analyzer:: Analyzer: Digital GSM standard EDGE_NB standard
Adjust Ref Level
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 16
Fig. 6 Measurement 1: Frame structure
The burst numbers in the drawing correspond to the timeslots of the GSM frame
0
(EDGE)
0
(EDGE)
7
(EDGE)
6
(EDGE)
5
(EDGE)
4
(EDGE)
3
(EDGE)
2
(EDGE)
1
(EDGE)
External Frame Trigger
0
(EDGE)
1
(EDGE)
0
(EDGE)
= Burst, Slot belegt
= Slot nicht belegt
= Burst, abgesenkter Pegel
structure. The transmitter settings cause a single EDGE burst in time slot 0. The time slots 1 to 7
are not assigned.
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 17
Measurement:
RMS-EVM:
< 0.5%
Center Frequency Error:
< 2 Hz
Fig. 7 shows a typical result display of the analyzer for the EDGE standard. In the upper half, the magnitude of the vector error is plotted over time; in the lower half
numeric error values in the range of the evaluation lines are listed.
Fig. 7 Measurement 1: Result display of analyzer
For this kind of measurement with adequately set reference level and synchronization of reference oscillators between transmitter and analyzer, the following results should be displayed.
The EDGE measurement must be performed with the measurement filter prescribed by ETSI. If DIGITAL STANDARD EDGE is selected, this filter is automatically switched on.
With the control sequence <SCREEN A>, <MEAS RESULT>, <MEAS SIGNAL>, <I/Q VECTOR>, the associated I/Q trace is displayed (after filtering with the measurement filter, Fig. 8). With the sequence <MEAS RESULT>, <RESULT RAW>, this filter is switched off and the measurement is performed on the raw transmitter signal (before filtering with the measurement filter). The associated display is shown in Fig. 9.
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 18
Fig. 8 Measurement 1: I/Q vector
Fig. 9 Measurement 1: RESULT RAW
Switching off the measurement filter may also influence the numeric result display: high-frequency noise components that are to a great extent suppressed by the filter may cause more measurement errors.
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 19
2.6 Measurement 2: Selection of a Specific Slot with Trigger
7
(EDGE)
5
(EDGE)
3
(EDGE)
1
(EDGE)
External Frame Trigger
TRIGGER OFFSET RECORD LENGTH
0
(EDGE)
4
(EDGE)
6
(EDGE)
2
(EDGE)
0
(EDGE)
Offset
Objective of the measurement:
● Selecting a single EDGE burst by external trigger
● Changing the position of the trace in the display with FIT TRACE
● Reducing the RECORD LENGTH
Instrument settings:
► Transmitter: GSM default setting
EDGE Full Frame
► Analyzer: Digital GSM standard EDGE_NB standard
<Adjust Ref Level> <TRIGGER> -> EXT <TRIGGER OFFSET> -100us < RESULT LENGTH = 200>
1) <MEAS RESULT> <MAG CAP BUFFER>
2) <MEAS RESULT> <RESULT RAW> <MEAS RESULT> <MEAS SIGNAL> <MAGNITUDE ABSOLUTE>
The transmitter settings cause EDGE bursts in time slots 0 to 7.
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 20
Measurement:
In the default setting, the TRIGGER OFFSET is set to -100 s and the RECORD LENGTH to 10 times the RESULT LENGTH. The received raw signal is displayed (magnitude capture buffer, Fig. 10).
With this setting the first detected pulse is demodulated. The name of the detected sync pattern that is used for synchronization is displayed (EDGE_TSC0, Fig. 11).
During the measurement, the TRIGGER OFFSET can be varied with the rotary knob until the EDGE_TSC3 sync pattern is displayed. Stable demodulation is achieved with a trigger offset of +1.1 ms.
Fig. 10 Meas. 2: Magnitude capture buffer
Fig. 11 Meas. 2: EDGE_TSC0
Display positioning
When GSM / EDGE is set, FIT PATTERN TO CENTER is selected for the display: the center of the detected sync pattern is represented in the center of the display.
Other possible settings are shown in the figures below:
● FIT TRIGGER TO LEFT: trigger time + trigger offset are displayed at the left screen
edge
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 21
● FIT PATTERN TO LEFT: the beginning of the sync pattern is displayed at the left
screen edge
Fig. 12 Meas. 2: FIT TRIGGER TO LEFT
Fig. 13 Meas. 2: FIT PATTERN TO LEFT
Changing the RECORD LENGTH
To speed up the measurement, the data recording time (RECORD LENGTH) can be manually reduced (set RECORD LENGTH = 250 symbols). In some cases, display positioning with FIT TRACE and 'pattern aligned’is no longer possible.
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 22
2.7 Measurement 3: Setting the Burst Search Parameters
Fig. 14 Burst-search parameter
7
(EDGE)
5
(EDGE)
3
(EDGE)
1
(EDGE)
External Frame Trigger
0
(EDGE)
4
(EDGE)
6
(EDGE)
2
(EDGE)
0
(EDGE)
(LEVEL)
Objective of the measurement:
● Manual setting of burst parameters
● Selective search for sync patterns
Instrument settings:
► Transmitter: GSM default setting
EDGE Full Frame Blank slot 0 and slot 2 Reduce level of slot 1 by 15 dB
► Analyzer: Digital GSM standard EDGE_NB standard
<Adjust Ref Level> <TRIGGER> FREE RUN <MEAS RESULT> <RESULT LENGTH = 200>
1) <DISPLAY><SPLIT SCREEN> <DISPLAY><SCREEN B> <MEAS RESULT> <MAG CAP BUFFER> <DISPLAY><SCREEN A> <MEAS RESULT> <MEAS SIGNAL> <MAGNITUDE ABS>
2) <DISPLAY><FULL SCREEN> <MEAS RESULT> <MEAS SIGNAL> <MAGNITUDE ABS>
This basic transmitter setting causes a single burst with reduced level in timeslot 1 and a sequence of bursts in timeslots 3 to 7.
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 23
Measurement:
n the previous measurement, a defined burst was selected for the measurement by means of an external trigger signal. If a suitable measurement signal is available, the specific burst can also be selected by manual setting of burst search parameters without external trigger.
The signal consists of a single burst of reduced level and a sequence of bursts of normal level. In automatic burst search, the level threshold depends on the maximum amplitude and slots 3 to 7 are measured. The single burst in slot 2 is not detected. Fig. 15 and Fig. 16 show different untriggered measurements in the AUTO mode.
Fig. 15 Meas. 3: Burst search AUTO, EDGE_TSC4
Fig. 16 Meas. 3: Burst search AUTO, EDGE_TSC3
In the next step, the burst search is set with a level threshold of -30 dB RefLvl (relative to reference level). Because of manual threshold setting, the level-reduced burst in slot 1 is now also detected and demodulated. Fig. 17 shows such a measurement.
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 24
Fig. 17 Meas. 3: Burst search, manual level setting
Knowing that slot 1 contains a single burst, the settings for the burst search can be even more selective:
Under <BURST & PATTERN> <EXPERT SETTINGS>, the GAP LENGTH (i.e. the gap between two consecutive bursts) is increased to 50 symbols.
The search algorithm now rejects all bursts in slots 3 to 7 and only identifies the burst in slot 1 as valid because this burst is between two empty timeslots and the only one in the frame to fulfill the burst conditions (see Fig. 17).

2.8 Measurement 4: Suppression of Incorrect Measurements

Objective of the measurement:
● MEAS ONLY ON PATT operating parameter
● Similarity of GSM and EDGE patterns
Instrument settings:
► Transmitter: GSM default setting
GSM Mixed Frame
► Analyzer: Digital GSM standard EDGE_NB standard
<Adjust Ref Level> <DISPLAY><FULL SCREEN> <MEAS RESULT> <MEAS SIGNAL> <MAGNITUDE ABS> <MEAS RESULT> <RESULT RAW>
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 25
The transmitter settings cause bursts in time slots 1 to 7. GSM and EDGE bursts are
0
(GSM)
0
(GSM)
7
(EDGE)
6
(GSM)
5
(EDGE)
4
(GSM)
3
(EDGE)
2
(GSM)
1
(EDGE)
External Frame Trigger
transmitted alternately.
Measurement:
The signal consists of a fully used frame in which EDGE and GSM bursts are transmitted alternately. In contrast to the standard setting for EDGE_NB, the MEAS ONLY ON PATT parameter is switched off. As a result, the analyzer tries to demodulate each burst that fulfills the burst conditions.
The EDGE demodulation algorithm is optimized for 3pi/8-8PSK modulation. It also synchronizes to GSM signals patterns of identical name, but a great number of error messages are issued in this case.
In the case of untriggered measurements, the following result displays may be obtained.
Fig. 18 Meas. 4: EDGE demodulator, correct demodulation
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 26
Fig. 19 Meas. 4: EDGE demodulator, incorrect demodulation of a GSM burst
The incorrect measurements can be avoided when the following settings are made:
● Select appropriate patterns for the EDGE signal (e.g. EDGE_TSC1,
EDGE_TSC3,EDGE_TSC5, EDGE_TSC7)
● Activate MEAS ONLY ON PATT softkeys
The display is only updated after a valid measurement. After a faulty measurement the display remains unchanged and the SEARCHING PATTERN message is displayed.
Despite the similarity of the GSM and EDGE sync patterns, the GSM demodulator is not able to identify EDGE patterns. To suppress invalid measurements (pattern not found), the MEAS ONLY ON PATT softkey must also be activated.

2.9 Measurement 5: Evaluation Lines

Objective of the measurement:
● Use of evaluation lines for determining result ranges
Instrument settings:
► Transmitter: GSM default setting
GSM Full Frame
► Analyzer: Digital GSM standard GSM_NB standard
<Adjust Ref Level> <DISPLAY> <SPLIT SCRREN>
1) <SCREEN A> <MEAS RESULT> <MAGNITUDE ABS> <SCREEN B> <MEAS RESULT> <SYM & MODUL ERR>
2) <SCREEN B> <MEAS RESULT> <MAGNITUDE ABS> <SIGNAL STATISTIC>
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 27
The transmitter settings cause GSM bursts in time slots 0 to 7.
External Frame Trigger
0
(GSM)
0
(GSM)
1
(GSM)
4
(GSM)
3
(GSM)
2
(GSM)
5
(GSM)
6
(GSM)
7
(GSM)
Measurement:
Evaluation lines delimit the range in which numeric results such as EVM, phase error, magnitude error, RHO are determined. The range is preset and automatically considered when a digital standard is set.
In the first figure below, the EVAL LINES are correctly set; in the second, they are set on the burst edge.
Fig. 20 Meas. 5: Setting the evaluation range: presetting the standard
Fig. 21 Meas. 5: Setting the evaluation range: extension to burst edges
R&S FSQ-K70/FSMR/FSU-B73 First Measurements - Getting Started
Software Manual 1161.8073.42 - 13 28
The evaluation lines also affect derived displays such as statistical signal evaluation. Fig. 22 shows the statistical level distribution within the burst. In Fig. 23, the EVAL LINES are extended to ranges outside the burst which is reflected by the level's probability of occurrence.
Fig. 22 Meas. 5: Level distribution within the burst
Fig. 23 Meas. 5: Level distribution within and outside the burst
The displayed measurements were performed in the SINGLE SWEEP mode. The display at the right was obtained solely by varying the EVAL LINE 1 without receiving new data. For this reason the measurement is marked with a red asterisk *. Parameters relating to this measurement (e.g. modulation errors or statistics diagrams) are recalculated, however.

R&S FSQ-K70/FSMR/FSU-B73 Brief Description of Vector Signal Analysis (Function)

Software Manual 1161.8073.42 - 13 29
3 Brief Description of Vector Signal Analysis
A D
Decimation
Filters
I Buffer
16 M
Q Buffer
16 M
Signal
Processor
NCO
20.4 MHz
Halfband
Filter
Resampling
Ratio
cos
sin
Sampling Rate =
81.6 MHz... 10 kHz
Trigger
Sampling Rate =
81.6 MHz.
IF=20.4
MHz
Equalizer
Filter
Q
I
Resampler
Decimation Record Buffer DSP
(Function)
The "Vector Signal Analysis" software option R&S FSQ-K70/FSMR-B73/FSU-B73 performs vector measurements for analyzing modulation errors of RF signals converted to the complex baseband. Carrier envelope and time domain measurements can also be performed but these measurements can be carried out in the basic unit (frequency analyzer) with a considerably wider bandwidth. The same applies to spectral measurements such as adjacent-channel power measurements on mobile radio signals.
The following sections describe the digital signal processing hardware, the interplay of analog and digital filters for bandwidth limiting, system-theoretical modulation and demodulation filters as well as the algorithms used by the measurement demodulator. The implemented modulation modes and the associated predefined symbol mappings are also listed.
The last part of this chapter deals with vector and scalar modulation errors. The required calculation formulae are provided in the Annex to this manual.

3.1 Block Diagram of Digital Signal Processing Hardware

Fig. 24 Block diagram of digital hardware for vector signal analysis

3.1.1 Description of Block Diagram

After having passed several RF, IF and filter stages, the RF input signal is converted to an IF of 20.4 MHz and applied to an A/D converter with a sampling frequency of exactly 81.6 MHz.
The digitized signal is then routed through two ICs for resampling (conversion of sampling rate by a real factor) and for filtering and decimation (reduction of sampling rate by an integral factor). An EQUALIZER FILTER is connected to the RESAMPLER input to compensate for the frequency response of the analog filter stages which would otherwise add to the modulation errors.
R&S FSQ-K70/FSMR/FSU-B73 Brief Description of Vector Signal Analysis (Function)
Software Manual 1161.8073.42 - 13 30
During operation, the filters and decimation factors of the instrument are set so that a
.In addition to setting the modulation mode, ACCURATE setting of symbol rate and filter parameters is important for a correct demodulation. Even slight deviations may noticeably impair the measurement result.
Examples are given in the Troubleshooting section.
A D
decimation
filters
I-Memory
16 M
Q-Memory
16 M
Processor
NCO
20.4 MHz
Halfband
Filter
Resampling
ratio
cos
sin
sampling rate =
326.4 MHz... 163.2 MHz
sampling rate =
326.4 MHz...>81.6MHz
Trigger
IF-Filter
120 MHz
sampling rate =
326.4 MHz.
IF=
408 MHz
sampling frequency is obtained at the output of the DECIMATION stage, which exactly corresponds to the following equation:
Sampling rate = Symbol rate * Points/symbol {4,8, or 16}; A higher point/symbol setting automatically results in a corresponding increase of the
I/Q bandwidth. The resulting measurement bandwidths are described in the sections below.
The complex output signal of the DECIMATION stage is stored in the I/Q memory (RECORD BUFFER) and forwarded to a signal processor (DSP) for further processing.
The data recording length and the result length after DSP processing are limited to about 32k samples (irrespective of the set symbol rate or sampling rate).
The received baseband signal is filtered in the subsequent DSP stage as required by the signal, then demodulated without the transmitted data being known (non-data­aided demodulator) and scanned for sync patterns. An ideal transmit signal is reconstructed from the demodulated data, and various modulation and vector errors, which are described in the following sections, are obtained from a comparison of demodulated and ideal I/Q signals.
Supplement to the R&S FSQ-B72 Option
The R&S FSQ-B72 option additionally allows sampling rates from >81.6 MHz to 326.4 MHz. With sampling rates 81.6 MHz, the R&S FSQ-B72 option is not active. The analyzer then behaves in the way described above. Fig. 25 shows the hardware of the analyzer from IF up to the processor for sampling rates above 81.6 MHz. An IF filter of 120 MHz is effective. The A/D converter samples the IF (408 MHz) at a rate of 326.4 MHz. The points/symbol setting parameter is fixed at {4}.
Fig. 25 Block diagram with the signal processing of the R&S FSQ at sampling rates >81.6 MHz

3.1.2 Bandwidths for Signal Processing

Relevant filters for vector signal analysis are shown in the block diagram below.
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