Rohde & Schwarz FSE-B7 User Manual

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Test and Measurement Division

Operating Manual

OPTION: SIGNAL VECTOR ANALYSIS FOR SPECTRUM ANALYZER FSE

FSE-B7

1066.4317.02

Printed in the Federal Republic of Germany

1066.4323.12 - 07 1

FSE-B7 Contents

Index Data sheet

Page

1 Preparation for Use..........................................................................................1.1-1

1.1 Introduction.........................................................................................................................1.1-1

2.2 Menu Overview ...................................................................................................................2.2-1

2.2.1 SYSTEM Key Group.................................................................................................2.2-1

2.2.2 CONFIGURATION Key Group .................................................................................2.2-4

2.2.3 HARDCOPY Key Group ...........................................................................................2.2-6

2.2.4 FREQUENCY Key Group.........................................................................................2.2-7

2.2.5 LEVEL Key Group, INPUT Key.................................................................................2.2-8

2.2.6 MARKER Key Group ..............................................................................................2.2-10

2.2.7 LINES Key Group ...................................................................................................2.2-11

2.2.8 TRACE Key Group..................................................................................................2.2-12

2.2.9 SWEEP Key Group.................................................................................................2.2-13

2.2.10 MEMORY Key Group..............................................................................................2.2-14

2.2.11 USER Key Group....................................................................................................2.2-14

2.4 Vector Analyzer Mode........................................................................................................2.4-1

2.4.1 Selecting the Operating Mode ..................................................................................2.4-2

2.4.2 Analog Demodulation Methods.................................................................................2.4-4

2.4.3 Digital Modulation Methods.....................................................................................2.4-29

2.4.4 Frequency Settings - FREQUENCY Key Group.....................................................2.4-61

2.4.5 Setting the Frequency Span - START, STOP, and SPAN Key...............................2.4-62

2.4.6 Setting the Level Display and Configuring the RF Input .........................................2.4-63

2.4.7 MARKER Key Group ..............................................................................................2.4-69

LINES

2.4.8 Setup of Display and Limit Lines –

2.4.9 Selection and Setting of Traces - TRACE Key Group............................................2.4-89

2.4.10 SWEEP Key Group.................................................................................................2.4-92

Remote Control is described in the operating manual for the corresponding instrument

Key Field..............................................2.4-79

1066.4317.02 3 E-5

Contents FSE-B7

Page

5 Checking Rated Specifications..........................................................................5.1

5.1 Preliminary Remarks:............................................................................................................5.1

5.2 Test Equipment Required..................................................................................................... 5.2

5.3 Test Procedure ...................................................................................................................... 5.3

5.3.1 Digital Demodulation....................................................................................................5.3

5.3.2 Analog Demodulation................................................................................................. 5.10

5.4 Performance Test Report.................................................................................................... 5.17

1066.4317.02 4 E-4

FSE-B7 Index

Index

DQPSK.....................................................................2.4-35

AC coupling...............................................................2.4-10

Alpha (roll-off factor)..................................................2.4-41

AM signal...................................................................

AM-demodulated time signal......................................2.4-13

Amplitude droop (sum error)..................................2.4-55

Amplitude modulation.............................................2.4-28

Analog Demodulation...................................................

Analysis bandwidth....................................................2.4-62

Anzeigebereich..........................................................2.4-23

Audio signal...............................................................2.4-13

Average .....................................................................2.4-17

carrier power .......................................................2.4-77

Averaging......................................................2.4-27,

Averaging of summary markers.................................2.4-77

2.4-13

2.4-6

2.4-90

Bandwidth

analog demodulation.............................................2.4-6

analog IF filters......................................................2.4-7

IF.........................................................................2.4-92

Bandwidth, analog.....................................................2.4-92

Bandwidth/symbol period product..............................2.4-41

BPSK......................................................................... 2.4-35

BT..............................................................................

Burst search..............................................................2.4-96

2.4-41

Capture buffer............................................................2.4-43

Capture buffer............................................................2.4-58

CCITT filter..................................................................2.4-9

CCITT P.53 .................................................................2.4-9

CDPD............................................................2.4-34, 2.4-36

Center frequency.......................................................2.4-61

Constellation diagram................................................2.4-48

Coupling

DC or AC.............................................................

CT2 ...........................................................................2.4-36

2.4-10

/4-DQPSK..................................................................2.4-35

D Lines......................................................................2.4-80

D8PSK.......................................................................2.4-35

DC coupling...............................................................2.4-10

DCS1800...................................................................2.4-36

Decision point............................................................2.4-50

DECT standard..........................................................2.4-35

Deemphasis...............................................................2.4-12

Delta markers............................................................2.4-72

DEMOD BANDWIDTH.................................................

Demodulation

analog ...................................................................2.4-6

bandwidth ..............................................................

Demodulation bandwidth. ............................................2.4-6

Demodulator, digital...................................................2.4-35

Demodulator,standard settings..................................2.4-36

Differential PSK.........................................................2.4-32

Digital demodulator....................................................

Digital modulation methods........................................2.4-29

Digital standard..........................................................2.4-36

Display range.............................................................2.4-65

Display width (eye diagram)...........................2.4-47, 2.4-50

DMSK........................................................................2.4-35

2.4-7

2.4-6

2.4-35

Dynamic range..........................................................2.4-64

EDGE........................................................................ 2.4-31

ERMES standard ......................................................2.4-36

Error

constellation diagram.......................................... 2.4-53

frequency............................................................2.4-52

frequency (FSK) (FSK)........................................2.4-53

magnitude........................................................... 2.4-52

magnitude (FSK)................................................. 2.4-53

magnitude of error vector.................................... 2.4-53

phase .................................................................. 2.4-52

real and imaginary part .......................................2.4-52

vector diagram.................................................... 2.4-53

Error signal................................................................2.4-52

External triggering..................................................... 2.4-95

Eye diagram.................................................. 2.4-46, 2.4-50

Eye length.................................................................2.4-47

2FSK......................................................................... 2.4-35

4FSK......................................................................... 2.4-35

Filter

input.................................................................... 2.4-39

reference.............................................................2.4-39

Find burst..................................................................

FLEX......................................................................... 2.4-36

Floating averaging.....................................................2.4-27

FM signal ..................................................................

FM-demodulated time signal..................................... 2.4-14

Frame length ............................................................. 2.4-59

Free-running trigger...................................................2.4-94

Frequency

carrier .................................................................2.4-61

offset................................................................... 2.4-61

setting accuracy.................................................. 2.4-61

Frequency error.........................................................2.4-52

Frequency error (FSK)..................................2.4-53, 2.4-57

Frequency error (sum error) ................................... 2.4-55

Frequency setting......................................................2.4-61

Frequency shift keying..............................................2.4-33

Frequency-demodulated signal .....................2.4-45, 2.4-50

FSK............................................................... 2.4-33, 2.4-36

deviation............................................................. 2.4-41

FSK deviation..........................................................2.4-57

FSK deviation error.................................................2.4-57

2.4-96

2.4-14

Group mid-points.......................................................2.4-42

GSM..........................................................................2.4-36

Hardkey

RANGE...............................................................

High pass AF filter.......................................................

2.4-23

2.4-9

1066.4317.02 I.1 E-5

Inhaltsverzeichnis FSE-B7

I/Q diagram................................................................2.4-48

I/Q imbalance (sum error) .......................................2.4-56

I/Q offset (sum error)...............................................2.4-56

IF bandwidth..............................................................2.4-92

IF BW AUTO ...............................................................

IF BW MANUAL...........................................................

IF filter.........................................................................2.4-7

INDICATION ABS REL..............................................

Inphase component...................................................2.4-48

Input filter...................................................................2.4-39

2.4-7

2.4-18

Key

CENTER .............................................................

COUPLING..........................................................2.4-92

D LINES..............................................................2.4-79

DELTA.................................................................

LIMITS ................................................................2.4-82

MKR ->................................................................

MODE...................................................................2.4-2

NORMAL.............................................................

REF.....................................................................2.4-64

SWEEP...............................................................2.4-93

TRACE................................................................2.4-89

TRIGGER............................................................2.4-94

2.4-61

2.4-72

2.4-78

2.4-69

Level

line ......................................................................2.4-80

Limit line

copy ....................................................................2.4-84

delete..................................................................2.4-84

save ....................................................................2.4-88

select...................................................................2.4-82

value ...................................................................2.4-88

Limit lines..................................................................2.4-81

Line

display 1,2...........................................................2.4-80

limit......................................................................2.4-81

reference.............................................................2.4-80

threshold.............................................................2.4-80

time 1, 2..............................................................2.4-80

Low pass AF filter........................................................

2.4-9

Magnitude

peak....................................................................2.4-76

Magnitude (capture buffer).........................................2.4-44

Magnitude (measurement signal)............................... 2.4-45

Magnitude (reference signal).....................................2.4-45

Magnitude error.............................................2.4-52, 2.4-53

Magnitude error (FSK).............................................2.4-57

Magnitude error (sum error)....................................2.4-55

Marker.......................................................................2.4-69

coupled................................................................2.4-70

delta....................................................................2.4-72

Marker ->.............................................................2.4-78

phase indication ..................................................2.4-70

polar diagram ......................................................2.4-70

search.................................................................2.4-73

Search Limit........................................................2.4-74

Max Hold...................................................................2.4-91

Mean.........................................................................2.4-77

Measurement (digital demodulation)..........................2.4-43

Measurement curve

minimum-value averaging................................... 2.4-91

peak-value averaging.......................................... 2.4-91

Measurement filter ....................................................2.4-39

Measurement signal

phase .................................................................. 2.4-45

Measurement signal (digital demodulation)...............2.4-44

Measuring time..........................................................2.4-19

Memory size.............................................................. 2.4-58

Min Hold.................................................................... 2.4-91

Minimum shift keying................................................. 2.4-34

Minimum-value averaging......................................... 2.4-91

MODACOM............................................................... 2.4-36

Mode

vector signal analysis............................................ 2.4-1

Modulation

summary.............................................................

Modulation error........................................................2.4-51

Modulation parameters.............................................. 2.4-38

analog demodulation.............................................

MSK.............................................................. 2.4-34, 2.4-35

2.4-15

2.4-8

NADC (IS54) ............................................................. 2.4-36

Normalization............................................................ 2.4-42

Number of sweeps.................................................... 2.4-77

Nyquist filter.............................................................. 2.4-41

OQPSK..................................................................... 2.4-35

Output formats (digital demodulation)........................2.4-44

Parameters

analog demodulation............................................. 2.4-8

Pattern.................................................................... 2.4-102

name.................................................................2.4-103

selection ...........................................................2.4-102

PCS1900...................................................................2.4-36

PDC.......................................................................... 2.4-36

Peak..........................................................................2.4-76

Peak hold.................................................................. 2.4-77

Peak-value averaging................................................2.4-91

Phase

shift.....................................................................2.4-45

Phase error............................................................... 2.4-52

Phase error (sum error) ..........................................2.4-55

Phase of the measurement....................................... 2.4-45

Phase shift keying..................................................... 2.4-30

Phase wrap...............................................................

PHS ..........................................................................2.4-36

PM signal..................................................................

Point of decision........................................................2.4-60

Points of decision (highlighting)................................. 2.4-49

Points per symbol......................................................2.4-60

Polar diagram............................................................ 2.4-48

marker.................................................................2.4-70

Polar marker..............................................................2.4-70

PSK...........................................................................2.4-30

differential...........................................................2.4-32

8PSK.........................................................................2.4-35

2.4-45

2.4-14

1066.4317.02 I.2 E-5

FSE-B7 Index

QAM..........................................................................2.4-34

16QAM......................................................................2.4-35

QCDMA.....................................................................2.4-36

QPSK........................................................................2.4-35

Quadrature amplitude modulation ..............................2.4-34

Quadrature component..............................................2.4-48

Range............................................................2.4-23, 2.4-65

Real time...................................................................2.4-19

REAL TIME ON...........................................................

Real-time demodulation...............................................2.4-4

Reference

deviation.............................................................. 2.4-41

filter.....................................................................2.4-39

level.....................................................................2.4-63

level offset...........................................................2.4-64

modulation...........................................................2.4-18

position................................................................2.4-67

signal (digital demodulation)................................2.4-44

value ...................................................................2.4-63

value (position)....................................................2.4-67

value X/Y axis .....................................................2.4-65

values..................................................................2.4-18

Reference deviation...................................................2.4-54

Reference line ...........................................................2.4-80

Reference signal (digital demodulator).......................2.4-40

Reference value

Y axis..................................................................

Reference value position...........................................2.4-23

Resolution bandwidth ................................................2.4-92

Result length......................................2.4-27, 2.4-60, 2.4-93

RF input

configuration........................................................2.4-68

Rho factor (sum error).............................................2.4-57

Rms value.................................................................2.4-76

Roll-off factor.............................................................2.4-41

2.4-4

2.4-23

Save

limit line...............................................................2.4-88

Scale unit...................................................................2.4-67

Scaling

AF output.............................................................2.4-19

vertical..................................................... 2.4-23, 2.4-65

Sensitivity

AF output.............................................................2.4-19

Side band..................................................................

SINAD measurement.................................................2.4-18

Slope.........................................................................

Soft key

ALPHA/BT...........................................................2.4-41

SYMBOL RATE................................................... 2.4-38

Softkey

+PEAK ................................................................

±PEAK ................................................................

50us....................................................................

750us ..................................................................

75us....................................................................

ACTIVE MKR / DELTA............................

AF COUPL'G AC/DC...........................................

AF SIGNAL .........................................................

ALL DELTA OFF.................................................

ALL MARKER OFF.............................................

ALL SUM MKR OFF............................................

AM SIGNAL.........................................................

AM/FM DEEMPH ................................................

2.4-11

2.4-22

2.4-76

2.4-12

2.4-74, 2.4-78

2.4-10

2.4-22

2.4-72

2.4-71

2.4-77

2.4-13

2.4-12

ANALOG DEMOD.................................................

AVERAGE..........................................................

AVERAGE/HOLD ON.........................................

AVERAGE/HOLD ON / OFF...............................2.4-77

BLANK................................................................ 2.4-89

CLEAR/WRITE................................................... 2.4-89

COMMENT (SYNC PATTERN).........................

CONTINOUS SWEEP........................................

CONTINUOUS SWEEP......................................

CONTINUOUS WRITE .......................................2.4-90

COPY LIMIT LINE...............................................

COUPLED MARKER..........................................

DEEMPHASIS ON/OFF......................................

DELETE LIMIT LINE...........................................

DELETE PATTERN..........................................

DELETE VALUE (limit line).................................

DELTA 1/2..........................................................

DELTA ABS / REL..............................................

DEMOD BANDWIDTH..........................................

DIGITAL DEMOD................................................

DIGITAL STANDARD......................................... 2.4-36

DISPLAY LINE 1/2..............................................

D-LINES..............................................................

EDIT SYNC PATTERN....................................

EDIT LIMIT LINE ................................................

ERROR SIGNAL.................................................

ERROR SIGNAL (FSK demodulation).................2.4-53

ERROR VECT MAGNITUDE.............................. 2.4-53

EXTERN.................................................

EYE DIAG [FREQ] (FSK demodulation)..............2.4-50

EYE DIAG [I].......................................................

EYE DIAG [Q].....................................................

EYE DIAG TRELLIS...........................................

EYE LENGTH.....................................................2.4-47

EYE LENGTH (FSK demodulation).................... 2.4-50

FIND BURST......................................................

FIND SYNC ON/OFF ..........................................

FM SIGNAL........................................................

FRAME LENGTH................................................ 2.4-59

FREE RUN.............................................

FREQUENCY (error)...........................................2.4-52

FREQUENCY (FSK demodulation).....................2.4-50

FREQUENCY (MSK demodulation).................... 2.4-45

FREQUENCY OFFSET......................................

FSK REF DEVIATION........................................

FREQUENCY (error............................................ 2.4-53

MAGNITUDE (error............................................. 2.4-53

HIGHPASS AF FILTER........................................

IF BANDWIDTH....................................................

IF BW AUTO.............................................

IF BW MANUAL........................................

INDICATION ABS REL .......................................

INSERT VALUE (limit line)..................................

LOW PASS AF FILTER........................................

MAGNITUDE...................................................... 2.4-45

MAGNITUDE (error)............................................2.4-52

MAGNITUDE (FSK demodulation) ...................... 2.4-49

MAGNITUDE CAP BUFFER............................... 2.4-44

MARKER INFO................................................... 2.4-71

MARKER1..2......................................................

MAX |PEAK| ...........................................

MAX HOLD.........................................................

MEAN.................................................................2.4-77

MEAS FILTER.................................................... 2.4-39

MEAS ONLY IF SYNC'D.....................................

MEAS RESULT ......................................

MEAS SIGNAL ...................................................

MEAS→REF.......................................................

MEMORY SIZE...................................................2.4-58

MIN.....................................................................

MIN HOLD..........................................................

2.4-21

2.4-74, 2.4-76

2.4-13

2.4-7

2.4-6

2.4-90

2.4-17

2.4-103

2.4-26

2.4-93

2.4-84

2.4-70

2.4-12

2.4-84

2.4-102

2.4-88

2.4-72

2.4-6

2.4-35

2.4-80

2.4-103

2.4-86

2.4-52

, 2.4-95

2.4-46

2.4-96

2.4-97

2.4-14

, 2.4-94

2.4-61

2.4-41

2.4-9

2.4-7

, 2.4-92 , 2.4-92

2.4-18

2.4-88

2.4-9

2.4-69

2.4-91

2.4-95

, 2.4-43

2.4-44

2.4-18

2.4-74

2.4-91

1066.4317.02 I.3 E-5

Inhaltsverzeichnis FSE-B7

MKR → TRACE...................................................

MODULATION PARAMETER...............................

MODULATION PARAMETERS...........................2.4-38

MODULATION SUMMARY .................................

NAME (limit line)..................................................

NAME (SYNC PATTERN) .................................

NEW LIMIT LINE.................................................

NEW SYNC PATTERN.....................................

NORMALIZE.......................................................2.4-42

PEAK ..................................................................

-PEAK.................................................................

PEAK HOLD ON / OFF.......................................2.4-77

PHASE................................................................2.4-45

PHASE (error).....................................................2.4-52

PHASE WRAP ON/OFF......................................2.4-45

PM SIGNAL.........................................................

POINTS PER SYMBOL.......................................2.4-60

POLAR [IQ] CONSTELL (error)...........................2.4-53

POLAR [IQ] CONSTELLATION...........................

POLAR [IQ] VECTOR..........................................

POLAR [IQ] VECTOR (error)............................... 2.4-53

POLAR MARKER DEG/ RAD..............................

POLAR MARKER R/I / MA/PH ............................

PRE DISPL ON/OFF...........................................

RANGE...................................................

REAL TIME ON/OFF...........................................2.4-19

REAL/IMAG PART..............................................2.4-45

REAL/IMAG PART (error)....................................2.4-52

REF LEVEL.........................................................

REF LEVEL OFFSET..........................................

REF VALUE POSITION..........................

REF VALUE X AXIS............................................

REF VALUE Y AXIS................................

REFERENCE LINE.............................................

REFERENCE SIGNAL........................................

REL UNIT............................................................

RESULT LENGTH...................................

RESULT LENGTH...............................................2.4-60

RMS....................................................................2.4-76

SAVE LIMIT LINE................................................

SAVE PATTERN...............................................

SCALE UNIT...........................................

SEARCH LIMIT ON/OF F.....................................2.4-74

SELECT LIMIT LINE...........................................

SELECT MARKER..............................................

SELECT PATTERN...........................................

SENSITIV AF OUTPUT...........................

SET REFERENCE..............................................

SHIFT X LIMIT LINE ...........................................

SHIFT Y LIMIT LINE ...........................................

SIDE BAND NORM / INV....................................

SIDEBAND INV...................................................

SIDEBAND NORM..............................................

SINAD 1 kHz ON.................................................

SINGLE SWEEP.....................................

SLOPE POS/NEG ...................................

SQUELCH LEVEL...............................................

SQUELCH ON.....................................................

SUM MKR...........................................................

SUMMARY MARKER..........................................

SUMMARY MEAS TIME.....................................

SUMMARY SETTINGS.......................................

SWEEP...............................................................

SWEEP COUNT..............

SWEEP COUNT..................................................2.4-77

SWEEP TIME......................................................

SYMB TABLE / ERRORS....................................2.4-54

SYMBOL DISPLAY.............................................

SYMBOL DISPLAY (FSK demodulation) .............2.4-50

SYNC OFFSET...................................................

SYNC PATTERN...............................................2.4-102

THRESHOLD LINE .............................................

2.4-17

, 2.4-27,

2.4-78

2.4-8

2.4-15

2.4-87

2.4-103

2.4-86

2.4-103

2.4-74

2.4-76

2.4-14

2.4-48

2.4-70

2.4-12

2.4-23

, 2.4-65

2.4-64

2.4-23

, 2.4-67

2.4-65

2.4-23

, 2.4-65

2.4-80

2.4-44

2.4-17

2.4-27

, 2.4-93

2.4-88

2.4-104

2.4-25

, 2.4-67

2.4-82

2.4-74

2.4-102

2.4-19

, 2.4-24

2.4-18

2.4-88

2.4-38

2.4-11

2.4-18

2.4-26, 2.4-93

2.4-22, 2.4-95

2.4-11

2.4-75

2.4-19

2.4-17

2.4-26

2.4-90

, 2.4-93

2.4-27

2.4-49

2.4-98

2.4-80

TIME LINE 1/2.................................................... 2.4-80

TRIGGER OFFSET................................

VALUE (SYNC PATTERN)...............................2.4-104

VALUES (limit line).............................................

VECTOR ANALYZER...........................................

VIDEO ....................................................

VIEW ..................................................................2.4-89

VOLUME.................................................

WEIGHTING AF FILTER..................................... 2.4-9

X OFFSET..........................................................

Y OFFSET..........................................................

Y PER DIV..............................................

Softkey REFERENCE FILTER..................................2.4-39

Squelch.....................................................................

SQUELCH LEVEL.....................................................

Sum level .................................................................2.4-63

Summary

numeric measured values...................................2.4-17

Summary Marker....................................................... 2.4-75

Sweep

continuous ..............................................2.4-26,

count....................................................... 2.4-77,

number................................................................2.4-17

single.................................................................. 2.4-93

single.................................................................. 2.4-26

time..................................................................... 2.4-27

Sweep number..........................................................2.4-27

Symbol decision point...............................................2.4-50

Symbol decision points..............................................2.4-49

Symbol mapping .......................................................2.4-30

Symbol rate...............................................................2.4-38

Symbol table............................................................. 2.4-54

Sync offset................................................................ 2.4-98

Sync pattern............................................................ 2.4-102

Sync pattern, editing ...............................................2.4-103

Sync search..............................................................

Synchronization sequence........................................2.4-97

2.4-22

2.4-21

2.4-20

2.4-23

, 2.4-95

2.4-88

2.4-2

, 2.4-94 , 2.4-24

2.4-84

, 2.4-65

2.4-11

2.4-93

2.4-90

2.4-97

TETRA...................................................................... 2.4-36

TFTS......................................................................... 2.4-36

Threshold line............................................................2.4-80

Time lines..................................................................2.4-80

Time signal

AM-demodulated.................................................2.4-13

FM-demodulated................................................. 2.4-14

PM-demodulated.................................................2.4-14

Trellis diagram...........................................................2.4-46

Trigger.......................................................................2.4-94

AF signal.............................................................

delay...................................................................2.4-95

edge, pos./neg.................................................... 2.4-95

external............................................................... 2.4-95

external voltage...................................................2.4-21

free run............................................................... 2.4-21

free running......................................................... 2.4-94

offset.......................................................

slope...................................................................2.4-22

threshold............................................................. 2.4-94

video...................................................................2.4-94

video voltage....................................................... 2.4-21

Trigger edge.............................................................. 2.4-22

2.4-22

, 2.4-95

Unit

relative display.................................................... 2.4-17

Y-axis..................................................................2.4-25

Unit circle.................................................................. 2.4-42

Unit, ..........................................................................2.4-67

1066.4317.02 I.4 E-5

FSE-B7 Index

Vector diagram..........................................................2.4-48

Vector error (sum error)..........................................2.4-55

Vector Signal Analyzer.................................................2.4-1

Video trigger..............................................................2.4-94

Volume......................................................................

2.4-20

WCPE....................................................................... 2.4-36

Weighting filter............................................................ 2.4-9

1066.4317.02 I.5 E-5

FSE-B7 Preparation for Use

1 Preparation for Use

1.1 Introduction

This manual is an ex tension to the FSE manual and des cribes exclus ively vector analysis functions . All other functions are described in the FSE manual. For a better orientation refer to the alphabetically arranged table below.

Subject Section in FSE manual

Basic Steps of Operat i on 2.3

Emulations AnnexE

Firmware Update 1.8

Gereral Configuration 2.4

Interfaces Annex A

List of Error Messages Annex B

Macros 2.8

Measurement Documentat i on 2.6

Programming Examples Annex D

Remote Control Command Processing and Status Reporting Syst em

Remote Control Introduct i on 3.1 to 3.5

Saving and Recalling Data Sets 2.7

Setup of Display and Limi t Lines 2.9.4

Status Display-Remote/Manual Control 2.5

3.7 to 3.8

1066.4317.02 1.1-1 E-1

Preparation for Use FSE-B7

This page is intentionally blank

1066.4317.02 1.1-2 E-1

FSE-B7 Menu Overview

2.2 Menu Overview

2.2.1 SYSTEM Key Group

SYSTEM

PRESET

DISPLAY

CAL

INFO

DISPLAY

FULL

SCREEN

SPLIT

SCREEN

ACTIVE

SCREEN A

ACTIVE

SCREEN B

SCREEN

COUPLING

CONFIG DISPLAY

CONFIG

DISPLAY

SELECT OBJECT

BRIGHTNESS

TINT

SATURATION

DEFAULT

COLORS

PREDEFINED

COLORS

LOGO

ON OFF

FREQUENCY

ON OFF

DATA ENTRY

OPAQUE

SCREEN

COUPLING

MODE

COUPLED

HORIZONTAL

SCALING

VERTICAL

SCALING

SCREENS UNCOUPLED

- Identical to analyzer mode

1066.4317.02 2.2-1 E-6

FSE-B7 Menu Overview

SYSTEM

PRESET

DISPLAY INFO

CAL

CALIBR ATE

CAL S HORT

CAL TOTAL

CAL RES BW

CAL LOG

CAL LO SUPP

CAL

CAL I/Q

I/Q

CAL CORR ON OFF

CALIBRATE

CAL RESULTS

PAGE UP

PAGE DOWN

- Identical to analyzer mode

1066.4317.02 2.2-2 E-6

FSE-B7 Menu Overview

SYSTEM

PRESET

CAL

DISPLAY INFO

INFO

INSTRUMENT

SETTINGS

FIRMWARE VERSIONS

HARDWARE+ OPTIONS

SELFTEST

SYSTEM

MESSAGES

HELP

FIRST TOPIC

TOPIC

LIST OF

TOPICS

HELP

ON HELP

RETURN

TO MENU

SYSTEM

MESSAGES

SELECT

MESSAGE

CLEAR

MESSAGE

CLEAR ALL

MESSAGES

UPDATE

MESSAGES

PAGE UP

SELFTEST

EXECUTE

TESTS

ENABLE

ALL TESTS

DISABLE

ALL TESTS

CLEAR TEST

RESULTS

PAGE UP

PAGE DOWN

INSTRUMENT

SETTINGS

PAGE UP

PAGE DOWN

PAGE UP

PAGE DOWN

- Identical to analyzer mode

1066.4317.02 2.2-3 E-5

FSE-B7 Menu Overview

2.2.2 CONFIGURATION Key Group a) In Digital Demodulation Mode (not FSK-Demodulation)

CONFIGURATION

MODE

SETUP

MODE

ANALYZER

RECEIVER

VECTOR ANALYZER

AF DEMOD

TRIGGER

FREE RUN

VIDEO

EXTERN

AF SIGNAL

TRIGGER OFFFSET

SLOPE POS NEG

VECTOR

ANALYZER DIGITAL

STANDARDS

DIGITAL

DEMOD

ANALOG

DEMOD

MODULATION PARAMETER

MEAS

RESULT

TRIGGER

RANGE

SWEEP TIME

DEMOD BANDWIDTH

IF BANDWIDTH

IF BW AUTO

IF BW MANUAL

RANGE SCALE

Y PER DIV

REF VALUE

Y AXIS

REF VALUE

X AXIS

REF VALUE

POSITION

SENSITIV

AF OUTPUT

VOLUME

SCALE

UNIT

SCALE

UNIT

Y UNIT

LOG[dB ]

Y UNIT

LINEAR

Y UNIT DEG

Y UNIT RAD

Y UNIT dBm

Y UNIT VOLT

Y UNIT WAT T

X UNIT

TIME

X UNIT SYMBOL

MEAS RESULT

AM SIGNAL

FM SIGNAL

PM SIGNAL

MODULATION SUMMARY

SUMMARY SETTINGS

SUMMARY MEAS TIME

REAL TIME

ON OFF

SENSITIV AF OUTPUT

VOLUME

SUMMARY

SETTINGS

AVERAGE/ HOLD ON

SWEEP COUNT

REL UNIT

INDICATION

ABS REL

SET REFERENCE

MEAS->REF

SINAD 1kHz

ON OFF

DEMOD

SETTINGS

HIGH PASS AF FILTER

LOW PASS

AF FILTER

WEIGHTING AF FILTER

AF COUPL’G

AC DC

SQUELCH

ON OFF

SQUELCH

LEVEL

SIDE BAND

NORM INV

AM/FM DEEMPH

DEEMPHASIS

ON OFF

HIGH PASS

AF F ILTE R

NONE 30 Hz 300 Hz

LOW PASS

AF FILTER

NONE 3 kHz 15 kHz

WEIGHTING

AF FILTER

CCITT

C-Message

AM/FM

DEEMPHASIS

50 us

75 us

750 us

PRE DISPL

ON OFF

1066.4317.02 2.2-4 E-6

FSE-B7 Menu Overview

b) In Analog Demodulation (REAL TIME ON)

CONFIGURATION

MODE

SETUP

MODE

ANALYZER

RECEIVER

VECTOR ANALYZER

AF DEMOD

TRIGGER

FREE RUN

VIDEO

EXTERN

AF SIGNAL

TRIGGER OFFFSET

SLOPE POS NEG

VECTOR

ANALYZER DIGITAL

STANDARDS

DIGITAL

DEMOD

ANALOG

DEMOD

MODULATION PARAMETER

MEAS

RESULT

TRIGGER

RANGE

SWEEP TIME

DEMOD BANDWIDTH

IF BANDWIDTH

IF BW AUTO

IF BW MANUAL

RANGE SCALE

Y PER DIV

REF VALUE

Y AXIS

REF VALUE

X AXIS

REF VALUE

POSITION

SENSITIV

AF OUTPUT

VOLUME

SCALE

UNIT

SCALE

UNIT

Y UNIT

LOG[dB]

Y UNIT

LINEAR

Y UNIT DEG

Y UNIT RAD

Y UNIT dB m

Y UNIT VO L T

Y UNIT WA TT

X UNIT

TIME

X UNIT SYMBOL

MEAS RESULT

AM SIGNAL

FM SIGNAL

PM SIGNAL

MODULATIO N SUMMARY

SUMMARY SETTINGS

SUMMARY MEAS TIME

REAL TIME

ON OFF

SENSITIV AF OU TPUT

VOLUME

SUMMARY

SETTINGS

AVERAGE/ HOLD ON

SWEEP COUNT

REL UNIT

INDICATION

ABS REL

SET REFERENCE

MEAS->REF

SINAD 1kHz

ON OFF

DEMOD

SETTINGS

HIGH PASS AF FILTER

LOW PASS

AF FILTER

WEIGHTING AF FILTER

AF COUPL’G

AC DC

SQUELCH

ON OFF

SQUELCH

LEVEL

SIDE BAND

NORM INV

AM/FM DEEMPH

DEEMPHASIS

ON OFF

HIGH PASS

AF F ILT ER

NONE 30 Hz 300 Hz

LOW PASS

AF FILTER

NONE 3 kHz 15 kHz

WEIGHTING

AF FILTER

CCITT

C-Message

AM/FM

DEEMPHASIS

50 us

75 us

750 us

PRE DISPL

ON OFF

1066.4317.02 2.2-5 E-5

FSE-B7 Menu Overview

CONFIG URATION

MODE

SETUP

See analyzer mod e

2.2.3 HARDCOPY Key Group

See analyzer mode

1066.4317.02 2.2-6 E-6

FSE-B7 Menu Overview

2.2.4 FREQUENCY Key Group

FREQUENCY

CENTER SPAN

START STOP

CENTER

FREQUENCY

OFFSET

MIXER

INTERNAL

MIXER

EXTERNAL

FREQUENCY

CENTER SPAN

START STOP

SPAN, START and STOP are without function in the vector analyzer mode!

1066.4317.02 2.2-7 E-5

FSE-B7 Menu Overview

2.2.5 LEVEL Key Group, INPUT Key

LEVEL

REF

RAN GE

REF LE VE L

RE F LEVEL

SINGLE

REF LEVEL

AUT O RA NG E

OFFSET

RF ATTE N

MANUAL

ATTEN AUTO

NORMAL

ATTEN AUTO

LOW NOISE

ATTEN AUTO

LOW DIST

MIXER LEVEL

LEVE L

REF

RANGE

RANGE SCALE

AUTO SCALE

Y PER DIV

REF VALUE

Y AXIS

REF VALUE

X AXIS

REF VALUE

POSITION

GRID

ABS REL

SCALE

UNIT

SCALE

UNIT

Y UNIT

LOG[dB]

Y UNIT LINEAR

Y UNIT

DEG

Y UNIT

RAD

Y UNIT dBm

Y UNIT VOLT

Y UNIT WATT

X UNIT

TIME

X UNIT SYMBOL

1066.4317.02 2.2-8 E-6

FSE-B7 Menu Overview

INPU T

INPUT

RF ATTEN MANUAL

ATTEN AUTO

NORMAL

ATTEN AUTO

LOW NOISE

ATTEN AUTO LOW DIST

MIXER LEVEL

INPUT

SELECT

INPUT

SELECT

RF INPUT

50 OHM

RF INPUT

75 OHM/RAM

RF INPUT

75 OHM/RAZ

1066.4317.02 2.2-9 E-5

FSE-B7 Menu Overview

2.2.6 MARKER Key Group

MARKER

NORMAL SEARCH

DELTA

POLAR MKR

R/I MA/PH

ALL MARKER OFF

MKR

MARKER NORMAL

MARKER 1

MARKER 2

COUPLED MARKERS

MARKER INFO

PHASE NOISE

MARKER

NORMAL SEARCH

DELTA

REFERENCE POINT

DELTA MKR ABS REL

ALL DELTA OFF

MKR

DELTA

MARKER DELTA 1

DELTA 2

REFERENCE

FIXED

POINT

REFERENCE

FIXED

DELTA MKR ABS REL

ALL DELTA

OFF

REFERENCE POINT

REF POINT

X VALUE

REF POINT

Y VALUE

NORMAL SEARCH

DELT A

MARKER SEARCH

PEAK

MIN

MAX |P EAK|

SUM MKR

ON OFF

SUMMARY

MARKER

SEARCH LIM ON

ACTIVE

MKR DELTA

OFF

SELECT

MARKER

MKR

SUMMARY

MARKER

MAX |P EAK |

+ PEAK

- PEAK

PEAK/2

RMS

MEAN

PEAK HO LD

ON OFF

AVERAGE

ON OFF

SWEEP COUNT

ALL MOD MKR OFF

NORMAL SEARCH

DELTA

MARKER

MKR

MARKER

PEAK

MKR

REF VALUE

MKR

TRACE

SELECT

ACTIVE

MKR DELTA

1066.4317.02 2.2-10 E-6

FSE-B7 Menu Overview

2.2.7 LINES Key Group

LINES

D LINES

LIMITS

D LINES

DISPLAY LINE 1

DISPLAY LINE 2

THRESH OLD

LINE

REFERENCE

LINE

TIME/SY MB

LINE 1

TIME/SYMB

LINE 2

SHOW

LINE IN FO

LINES

D LINES

LIMITS

LIMIT

SELECT

LIMIT LINE

NEW LIMIT

LINE

EDIT LIMIT

LINE

COPY LIMIT

LINE

DELETE

LIMIT LINE

x OFFSET

Y OFFSET

PAGE UP

PAGE DOWN

1066.4317.02 2.2-11 E-5

FSE-B7 Menu Overview

2.2.8 TRACE Key Group

TRACE

TRACE 1

CLEAR/ WR IT E

VIEW

BLANK

CONTINUOUS WRITE

AVERAGE

MAX HOLD

MIN HOLD

SWEEP COUNT

1066.4317.02 2.2-12 E-6

FSE-B7 Menu Overview

2.2.9 SWEEP Key Group

SWEEP

TRIGGER

SWEEP

RBW VBW SWT

COUPLING

TRIGGER

FREE RUN

VIDEO

EXTERN

TRIGGER

OFFSET

SLOP E POS NEG

MEAS ONLY IF SYNC’D

FIND BURST

ON OFF

FIND SYNC ON OFF

SYNC

OFFSET

SYNC

PATTERN

SYNC

PATTERN

SELECT

PATTERN

NEW SYNC

PATTERN

EDIT SYNC

PATTERN

DELETE

PATTERN

COUPLING

PAGE UP

DEFAULT

PAGE DOWN

EDIT SYNC

PATTERN

NAME

VALUE

COMMENT

SAVE

PATTERN

SWEEP

TRIGGER

SWEEP

RBW VBW SWT

COUPLING

SWEEP

CONTINOUS

SWEEP

SINGLE

SWEEP

SWEEP COUNT

SWEEP

TIME

RESULT LENGTH

SWEEP

TRIGGER

SWEEP

RBW VBW SWT

COUPLING

COUPLED FUNCTIONS

ANALOG BW

AUTO

ANALOG BW

MANUAL

SWEEPTI ME

TIME CPLD

TO SPAN

1066.4317.02 2.2-13 E-5

FSE-B7 Menu Overview

2.2.10 MEMORY Key Group

See analyzer mode

2.2.11 USER Key Group

See analyzer mode

1066.4317.02 2.2-14 E-6

FSE-B7 Vector Analyzer Mode

2.4 Vector Analyzer Mode

The Vector Signal Analyzer in the FSE allows the analysis of analog and digital modulations. For this purpose, the FSE samples the IF signal which is band-limited by the resolution bandwidth (RBW ) and mixes it into the complex baseband. The real and im aginary section of the signal is then digitally filtered and further processed in digital signal processors. The complex baseband contains the whole signal information which can be evaluated according to the different criteria.

Decimate

Phi

IF filter

20 to

25.6 M H z

Dig LO

Memory

DSP

56002

Decimate

Fig. 2.4-1 Block diagram of FSE vector signal analyzer Three types of analysis are distinguished in the vector signal analyzer:

• In the analog demodulation m ode, the amplitude (AM), frequency (FM) or phase (PM) demodulated signal is represented as a function of tim e. Alternatively, display of a table containing the numerical demodulation parameters can be selected

(RESULT DISPLAY)

• For digitally modulated signals, the m ost comm only used demodulators are available to evaluate the modulation parameters.

• In the

DIGITAL DEMODULATION

mode, the magnitude of the non-demodulated signal c an also be

displayed (MAGNITUDE CAP BUFFER).

1066.4317.02 2.4-1 E-3

Vector Analyzer Mode FSE-B7

2.4.1 Selecting the Operating Mode

The vector analyzer mode is activated in the

CONFIGURATION

MODE

SE P

The type of analysis is selected in the

VECTOR ANALYZER

MODE

ANALYZER

VECTOR

ANALYZER

VECTOR ANALYZER

VECTOR

ANALYZER

DIGITAL

STANDARDS

DIGITAL

DEMOD

ANALOG

DEMOD

CONFIGURATION MODE

The

MODE

key calls up the menu for selecting the

operating mode.

sub menu

VECTOR ANALYZER

softkey calls up a subm enu. The specific settings for the vector analyzer are entered into this submenu.

The menus for the test parameter settings lying below these keys (

COUPLING, TRIGGER

FREQUENCY, LEVEL, MARKER, TRACE,

) are adapted to the specific

capabilities of the vector signal analyzer.

MODULATION

PARAMETER

MEAS

RESULT

TRIGGER

DIGITAL STANDARDS, DIGITAL DEMOD

The

ANALOG DEMOD

softkeys are selectors with which the

and

required type of analysis is set.

MODULATION PARAMETER

The

softkey sets the required modulation parameters for the demodulation of digitally modulated signals.

RANGE

MEAS RESULT

The

softkey calls up a subm enu in which

the required evaluation of the selected type of analysis is

SWEEP

TIME

set. For digital demodulation, for example, this is the evaluation of the signal itself or the reference signal, I/Q or vector errors etc.

DEMOD

BANDWDITH

The

TRIGGER

softkey calls up a menu equal to the

SWEEP TRIGGER

The

RANGE

The

IF BANDWIDTH

softkey calls up the sam e menu called by the

key in the

menu.

LEVEL

key group.

softkey calls up a subm enu in which

the analog IF Bandwidth is set.

Note: If two displays (screen A and screen B) are opened after switch-on of the vector signal

analysis, the vector analyzer mode is only set for the dis play activated for entr y (marked at the top right corner of diagram). For the other display, the previous settings remain valid. Storage and display of measured values is sequential: first in the upper and then in the lower display.

1066.4317.02 2.4-2 E-3

FSE-B7 Vector Analyzer Mode

The configuration of the vector analysis is performed in four steps:

1. Setting the type of analysis: Analog demodulation of the signal demodulation of digitally modulated signals ( transmission mode (

2. Selecting the modulation parameters (

3. Selecting the required measurement results (

4. Selecting the output format for measurement results (

DIGITAL STANDARDS,

MODULATION PARAMETER

DIGITAL DEMOD)

in this case, step no. 2 can be skipped).

MEAS RESULT)

or setting as required by a specific

RESULT DISPLAY

(ANALOG DEMOD),

general

1066.4317.02 2.4-3 E-3

Analog demodulation methods FSE-B7

2.4.2 Analog Demodulation Methods

With am plitude, frequency and phase demodulation, the FSE pr ovides all demodulation m ethods which can be used for analog RF carrier m odulation or which may impair a carrier. The bandwidth used for demodulation depends on the demodulation bandwidth selected. Make sure that the entire modulation spectrum is included in the demodulation bandwidth. Otherwise, signal distortions that impair the modulation will be caused by analog prefiltering with the IF filters of the FSE and digital filtering for suppression of aliasing products due to sampling or data reduction. Correct measurement of the modulation parameters will no longer be possible.

For correct demodulation make sure that only the signal to be analyzed is located within the demoduation bandwidth

(DEMOD BANDWIDTH)

impaired by adjacent signals. Spectral com ponents of adjacent signals should be at a distance of at least 1.285 times the (demodulation bandwidth)/2 from the center frequency (= carrier frequency).

of the FSE. Otherwise, the demodulation would be

Depending on the demodulation bandwidth set (

DEMOD BANDWIDTH

), two modes of demodulation are

provided:

DEMOD BANDWIDTH

With demodulation can be selected, with

≤ 200 kHz real-time

DEMOD BANDWIDTH

(REAL TIME ON)

> 200 kHz only offline demodulation is

or offline

(REAL TIME OFF)

possible. Real-time and offline demodulation differ as follows:

• Real-time demodulation

♦ The bandwidth of the demodulated signal can be reduced in the AF region using switchable

(REAL TIME ON)

highpass, lowpass or weighting filters (CCITT or C-message filter) to enable spurious modulation measurements for analog radio systems in line with the standard; moreover, deemphases can also be switched on for FM (and AM). A deemphasis, if switched on, has an effect on the audio signal (provided via loudspeaker or headphones connector) and on the result display or on the audio signal only. The switchable filters, however, always have an effect on the display and AF/loudspeaker output.

♦ The demodulated signal can be monitored via the built-in loudspeaker or via the headphones

output.

♦ In addition, the demodulated signal (parts of it) or a summary of numerical modulation parameters

can be displayed on the sceen. With the aid of the split screen display, the demodulated signal and the summery of numerical modulation parameters can be displayed at the same time.

• Offline demodulation

♦ The demodulation is not carried out continuously, but in blocks, ie a data block is written into the

(REAL TIME OFF)

memory and then demodulated and displayed:

♦ The measurement result displayed on the screen is the time function of the demodulated AF signal

and/or a summary of numerical modulation parameters.

♦ The internal loudspeaker, the headphones output is switched off. ♦ No highpass filters and no weighting filters can be activated.

Deemphases cannot be switched on.

♦ To restrict the noise bandwidth, AF lowpass filters can be selected, standardized to the

demodulation bandwidth (cutoff frequency = 5, 10 or 25 % of demodulation bandwidth).

The two demodulation modes provided are designed for the following main applications:

• Real-time demodulation (

REAL TIME ON

) for demodulation bandwidths up to max. 200 kHz for

modulation measurements to the standard on analog radio systems and also for monitoring.

• Offline demodulation (

REAL TIME OFF

), especially for measurement of transients (e.g. frequency

settling of oscillators and synthesizers).

The following diagram shows the menus which permit to set the par ameters and the result dis play with analog demodulation.

1066.4317.02 2.4-4 E-2

FSE-B7 Analog demodulation methods

Menu: CONFIGURATION MODE - VECTOR ANALYZER - ANALOG DEMOD (with REAL TIME ON)

VECTOR ANALYZER

TRIGGER

FR EE RUN

VIDEO

EXTERN

AF SIG N AL

TRIGG E R OFFFS E T

SLOPE POS NEG

VECTOR

ANALYZER DIGITAL

STANDARDS

DIGITAL

DEMOD

ANALOG

DEMOD

MODULATION PARAMETER

MEAS

RESULT

TRIGGER

RANGE

SWEEP TIME

DEMOD BANDWIDTH

IF BANDWIDTH

IF BW AUTO

IF BW MANUAL

RANGE SCALE

Y PER DIV

REF VALUE

Y AXIS

REF VALUE

X AXIS

REF VALUE

POSITI ON

SENSITIV

AF OUTP U T

VOLUME

SCALE

UNIT

MEAS RESULT

AM SIGNAL

FM SIGNAL

PM SIGNAL

MODULATION SUMMARY

SUMMARY SETTINGS

SUMMARY MEAS TIME

REAL TIME

ON OFF

SENSITIV AF OUTPUT

VOLUME

SCAL E

UNIT

Y UNIT

LOG[dB]

Y UNIT

LINEAR

Y UNIT DEG

Y UNIT RAD

Y UNI T dB m

Y UNI T VO LT

Y UNI T WA TT

SUMMARY

SETTINGS

AVERAGE/ HOLD ON

SWEEP COUNT

REL UNIT

INDICATION

ABS REL

SET REFERENCE

MEAS->REF

SINAD 1kHz

ON OFF

DEMOD

SETTINGS

HIGH PASS AF FILTER

LOW PASS

AF FILTER

WEIGHTING AF FILTER

AF COUPL’G

AC DC

SQUELCH

ON OFF

SQUELCH

LEVE L

SIDE BAND

NORM INV

AM/FM DEEMPH

DEEMPHASIS

ON OFF

HIGH PASS

AF FILTER

NONE 30 Hz 300 Hz

LOW PASS

AF FILTER

NONE 3 kHz 15 kHz

WEIGHTING

AF FILTER

CCITT

C-Message

AM/FM

DEEMPHASIS

50 us

75 us

750 us

PRE DISPL

ON OFF

X UNIT

TIME

X UNIT SYMBOL

Fig. 2.4-2 Menu structure for setting the demodulation with analog-modulated signals

1066.4317.02 2.4-5 E-2

Analog demodulation methods FSE-B7

ANALOG

DEMOD

MODULATION PARAMETER

MEAS RESULT

TRIGGER

The

ANALOG DEMOD

softkey activates the analog demodulation mode. The demodulation (AM, FM and PM demodulation) is performed in parallel. The type of demodulation or display (AM, FM or PM or numeric al display) is

set under MEAS RESULT.

See section "Selecting the Modulation Parameters"

See section "Selecting the Audio Signal"

See section "Triggering with Analog Demodulation - Softkey Hardkey

TRIGGER

RANGE

SWEEPTIME

DEMOD BANDWIDTH

See section "Setting the Display Range and the Scaling - Softk ey Hardkey

RANGE

See section "Sweep Menu with Analog Demodulation - Softkey or Hardkey

The

SWEEP

DEMOD BANDWIDTH

softkey calls up a field for entering the

RANGE

SWEEP TIME

demodulation bandwidth. The spectrum to be demodulated should be located completely within this

bandwidth, if possible (check in spectrum analyzer mode) in order to avoid demodulation distortions. Spurious signals outside the spectrum to be demodulated do not cause any demodulation errors if the frequency spacing with respect to the tuning frequency is (

1.28 x ( The

DEMOD BANDWIDTH

)/2.

can be set in steps of 1, 2, 3 and 5 in the range

CENTER FREQUENCY

) Delta f ≥

from 5 kHz to 5 MHz or, if diff erent entries are made, it will be rounded off to the nearest possible step.

With FM demodulation the maximum deviation that can be measured is restricted to (0.4 x

DEMOD BANDWIDTH

1066.4317.02 2.4-6 E-2

FSE-B7 Analog demodulation methods

BANDWIDTH

IF BW AUTO

IF BW MANUAL

The

IF BANDWIDTH

softkey opens up a submenu where the bandwidth of the analog IF filters is set (corresponds to the resolution bandwidth in spectrum analyzer mode).

IF BW AUTO

IF BW MANUAL

The

IF BW AUTO

softkey is used to set the IF bandwidth to the maximum

possible value 10 MHz (irrespective of the demodulation bandwidth).

The

IF BW MANUAL

softkey permits to restrict the analog IF bandwidth

specifically. To avoid modulation distortions and errors it is recommended to set the IF

bandwidth as large as possible (

IF BANDWIDTH

≥ 5 x

DEMOD BANDWIDTH

If spurious signals are to be suppressed outside the useful modulation spectrum, IF BW MANUAL can be used to r educe the IF bandwidth down to a value equal to the demodulation bandwidth.

Possible input values: ≥

DEMOD BANDWIDTH

, 5 kHz to 10 MHz.

1066.4317.02 2.4-7 E-2

Analog demodulation methods FSE-B7

2.4.2.1 Selecting the Modulation Parameters

Submenu:

MODULATION PARAMETER

REAL TIME ON

MODULATION PARAMETER

CONFIGURATION MODE - VECTOR ANALYZER - ANALOG DEMOD

The

MODULATION PARAMETER

softkey calls up a submenu which permits to

select the modulation parameters for analog demodulation.

Which menu is displayed depends on whether real-time demodulation is

MODULATIOJN

PARAMETER HIGH PASS

AF FILTER

LOW PASS

AF FILTER

WEIGHTING AF FILTER

AF COUPL’G

AC DC

SQUELCH

ON OFF

SQUELCH LEVEL

SIDE BAND

NORM INV

AM/FM DEEMPH

DEEMPHASIS

ON OFF

activated

HIGH PASS

AF FILTER

NONE 30 Hz 300 Hz

LOW PASS

AF FILTER

NONE 3 kHz 15 kHz

WEIGHTING

AF FILTER

CCITT

C-Message

DEEMPHASIS

(REAL TIME ON)

AM/FM

50 us

75 us

or not

(REAL TIME OFF)

REAL TIME OFF

MODULATION PARAMETER

MODULATIOJN

PARAMETER

HIGH PASS AF FILTER

LOW PASS

AF FIL T ER

WEIGHTING AF FILTER

AF COUPL’G

AC DC

SQUELCH

ON OFF

SQUELCH

LEVEL

SIDE BAN D

NORM INV

AM/FM DEEMPH

DEEMPHASIS

ON OFF

AF FILTER

LOW PASS

NONE 5 % [DEMOD BW] 10 % [DEMOD BW] 25 % [DEMOD BW]

750 us

PRE DISPL

ON OFF

Note: The dashed softkeys cannot be activated in the operating mode selected

1066.4317.02 2.4-8 E-2

FSE-B7 Analog demodulation methods

The possible selection of the filter depends on whether real-time demodulation is activated or not (

REAL TIME ON:

REAL TIME ON/OFF

HIGH PASS

AF FILTER

LOW PASS

AF FILTER

WEIGHTING

AF FILTER

The softkeys

HIGHPASS AF FILTER

and

LOW PASS AF FILTER

call up input fields which permit to select highpass or lowpass filters for restriction of the AF bandwidth.

HIGH PASS

AF FILTE R

NONE 30 Hz 300 Hz

REAL TIME ON

LOW PASS

AF FILTER

NONE 3 kHz 15 kHz

is activated, the opposite highpass and lowpass filters as

well as standard weighting filters can be selected. If AF filters are switched on, they act on the display and AF output or

loudspeaker output. The 3-dB cutoff frequencies are indicated for the highpass and lowpass

filters. 1st-order highpass filters (6 dB/octave slope) and 2nd-order lowpass filters

(12 dB/octave slope) are used. The

WEIGHTING AF FILTER

softkey calls up the inpit firld for selection of a standard weighting filter. The CCITT filter (CCITT P.53) and the C-message filter are used as weighting filters according to US standard.

WEIGHTING

AF FILTER

CCITT

C-Message

When one of the two weighting filters is activated, the demodulation bandwidth is automatically switched to 30 kHz. If the demodulation bandwidth is subsequently changed with active weighting filter, the latter is switched off.

REAL TIME OFF

If R

EAL TIME OFF

is selected, only lowpass filters can be activated for

restriction of the noise bandwidth.

AF FILTER

LOW PASS

NONE 5 % [DEMOD BW] 10 % [DEMOD BW] 25 % [DEMOD BW]

The filter bandwidth (-3 dB) can be selected in % of the demodulation bandwidth.

5, 10 or 25 % of the demodulation bandwidth are possible. The filters are designed as 2nd-order Butterworth filters (12 dB/octave

slope).

1066.4317.02 2.4-9 E-2

Analog demodulation methods FSE-B7

AF COUPL’G

AC DC

The

AF COUPL’G AC/DC

demodulators to DC or AC voltage coupling.

FM: With FM, AC coupling (

center frequency of the signal to be measured and correcting the demodulated signal accordingly.

AF COUPL’G DC

With carrier frequency, and no frequency correction is perf ormed. The AF signal is DC-coupled.

PM: With PM, AC coupling (

frequency offset and the phase offset and setting them to zero. Only with With

deviates, the phase varies with a period corresponding to the difference between applied and set center frequency (0 to 360°). If the frequency is consistent (e.g. in the case of synchronization to a common reference frequency) the phase is constant on an offset in the range from 0 to 360°. The PM demodulator is DC-coupled.

REAL TIME OFF

AF COUPL’G DC

softkey switches the AF analysis stages after the

AF COUPL’G AC

the center frequency of the FSE is assumed as the

AF COUPL’G AC

, if the center frequency of the signal to be measured

) is achieved by determining the

) is achieved by estimating both the

AM: As a mere envelope demodulator, the AM demodulator is insensitive to

frequency errors as long as carrier and sidebands are within the set frequency display range.

In the case of AC coupling ( is standardized to the DC voltage (corresponds to the aver age c arr ier value) and the DC component is removed.

The amplitude of the AF signal is directly proportional to the AM modulation depth.

In the case of DC coupling ( demodulated signal is proportional both to the AM depth and to the level, there is no standardization to the average carrier value. The measured value is displayed in absolute level units.

AF COUPL’G AC

AF COUPL’G DC

), the demodulated AF signal

), the amplitude of the

1066.4317.02 2.4-10 E-2

FSE-B7 Analog demodulation methods

SQUELCH

ON OFF

SQUELCH LEVEL

REAL TIME ON:

The

SQUELCH ON

softkey mutes the louds peaker or headphones output provided that the level falls below a threshold that can be entered under SQUELCH LEVEL. The trace of the dem odulated signal is also set to zero at this point in time. The muting circuit responds with a delay that is designed such that a signal modulated with ≥ 30 Hz AM does not cause the circuit to respond in a modulation low status.

Loudspeaker or headphones output are only active if real-time dem odulation is selected.

REAL TIME OFF:

With

MEAS RESULT: AM-, FM SIGNAL

:PM SIGNAL

the frequency or phase deviation is set to zero when the value falls below the squelch. The muting circuit responds without delay, which is why it is suitable for transient measurements in particular.

SQUELCH LEVEL

which the SQUELCH function is activated (only with

permits to enter an absolute level in the unit dBm , below

SQUELCH ON

SIDEBAND

NORM INV

The softkey

SIDEBAND INV (INVERTED)

demodulates and inverts the

signal received. Thus, with FM or PM demodulation, a receive signal with increasing

frequency at the FSE input leads to a falling AF signal. Default status is

SIDEBAND NORM

(normal): A receive signal with

increasing frequency at the FSE input leads to an increasing AF signal.

1066.4317.02 2.4-11 E-2

Analog demodulation methods FSE-B7

AM/FM DEEMPH

AM/FM

DEEMPHASIS

50 us

75 us

750 us

PRE DISPL

ON OFF

REAL TIME ON

AM/FM DEEMPH

The

only

softkey opens the submenu in which a deemphasis can be selected for FM (or AM) demodulation (An AM deemphasis is prescribed in a few regulations for measurement of synchronous amplitude modulation on FM transmitters.).

Deemphases with the time cons tants 50 µs, 75 µs (used for radio broadcasting) and 750 µs (used for radio communication) are provided.

If switched on, the deemphasis acts on the audio output.

DEEMPHASIS

ON OFF

50 us

REAL TIME ON only

The

75 us

constant of the deemphasis

The default setting is 50 µs.

750 us

REAL TIME ON only

PRE DISPL

ON OFF

The effect of the deemphasis to the result display.

Via the function effect of the deem phasis can also be extended to the res ult display to enable spurious modulation measurements complying with the standard.

To be able to measure the correct deviation of the signal applied in spite of the corrected audio signal, the active deemphasis can be switched of f via result display.

REAL TIME ON

DEEMPHASIS ON/OFF

The under

AM/FM DEEMPHASIS

50us, 75 us

PRE DISPL ON/OFF

PRE DISP ON

only

softkey switches the demphasis selected

on or off.

and

750 us

softkeys select the time

softkey switches on or off the

(PRE DISPLAY ON) the

PRE DISP OFF

for the

In the default status, the deemphasis is switched of

1066.4317.02 2.4-12 E-2

FSE-B7 Analog demodulation methods

2.4.2.2 Selecting the Audio Signal

Submenu:

MEAS

RESULT

CONFIGURATION: MODE - VECTOR ANALYZER - ANALOG DEMOD

MEAS RESULT

AM SIGNAL

The

MEAS RESULT

softkey opens up a submenu for selection of the AM, FM, or PM demodulated audio signal (display and audio output).

FM SIGNAL

PM SIGNAL

MODULATION SUMMARY

SUMMARY SETTINGS

SUMMARY MEAS TIME

REAL TIME

OFF

ON OFF

SENSITIV AF OUTPUT

AM SIGNAL

VOLUME

The

AM SIGNAL

softkey is used to display the AM-demodulated time s ignal provided that MODULATION SUMMARY is not active. If MODULATION SUMMARY is active, the modulation parameters will be numerically displayed with main signal AM (see MODULATON SUMMARY).

1066.4317.02 2.4-13 E-2

Analog demodulation methods FSE-B7

The AM-demodulated signal is applied to the audio output (if

REAL TIME ON)

FM SIGNAL

PM SIGNAL

FM SIGNAL

that MODULATION SUMMARY is not active. If MODULAT ION SUMMARY is active, the modulation param eter will be numerically displayed with main signal FM (see MODULATION SUMMARY).

The FM-demodulated signal is pr esent at the audio output (in the case of real-time demodulation).

The

PM SIGNALL

provided that MODULATION SUMMARY is not active. If MODULATION SUMMARY is active, the modulation parameter will be numerically displayed with main signal PM (see MODULATION SUMMARY).

In the case of audio output.

softkey displays the FM-demodulated time signal provided

softkey displays the PM-demodulated time signal

REAL TIME ON

the PM-demodulated signal is pres ent at the

1066.4317.02 2.4-14 E-2

FSE-B7 Analog demodulation methods

The

MODULATION SUMMARY

display of the audio signal versus time to the summary of the numeric modulation parameters.

Of the main signal in question the positive and negative peak modulation value, peak-to-peak value as well as the rms value are displayed with absolute display (see

SUMMARY SETTING

detector does not display the peak-to-peak value, but the average from positive and negative peak value).

Parallel to the main signal, the parameter s of the remaining demodulators are also displayed, ie the absolute, arithmetic average from positive and negative peak value.

The following parameters of the demodulation main signal can be displayed in addition:

• SINAD value (1-kHz modulation frequency fixed)

• Audio frequency

In addition, the frequency error as well as the carrier power (to be more exact: power of the unmodulated carr ier) and the configuration of the active AF filter and deemphasis are displayed.

softkey (on/off switch) switches from the

) (except for AM DC: the +-Pk/2

Example: AM signal/REAL TIME ON:

CF 978.3 MHz

Ref Lvl 10 dBm

Bit No.

AM: 54.20 % +Pk 54.68 -Pk

54.44 % PK/2 33.3 % RMS

SINAD 1 kHz: 35.1 dB AUDIO FREQ: 1.001 kHz FREQ ERROR: 101.1 Hz CARR PWR: 7.88 dBm FILTER: HP 30 Hz LP 3 kHz DEEMPH OFF

FM: 1.031 kHz PK/2 PM 1.011 rad PK/2

Symbol Table

MODULATION SUMMARY AM

DEMOD BW: 100 kHz

Example: AM signal/REAL TIME OFF:

CF 978.3 MHz

Ref Lvl 10 dBm

Bit No.

AM: 54.20 % +Pk 54.68 -Pk

54.44 % PK/2 33.3 % RMS

SINAD 1 kHz: -AUDIO FREQ: 1.001 kHz FREQ ERROR: 101.1 Hz CARR PWR: 7.88 dBm FILTER: HP -- LP 10 % [DEMOD BW] DEEMPH OFF

FM: 1.031 kHz PK/2 PM 1.011 rad PK/2

Symbol Table

MODULATION SUMMAR Y AM

DEMOD BW: 100 kHz

REAL TIME OFF MOD SUMMARY AM

ANALOG DEMOD

REAL TIME ON

MOD SUMMARY AM ANALOG DEMOD

1066.4317.02 2.4-15 E-2

Analog demodulation methods FSE-B7

Example: FM signal, relative measurement:

In the case of relative meas urement, the absolute arithm etic average from positive and negative peak value as well as the rms value of the main signal are also displayed. The separate display of positive and negative peak value is omitted. Instead, the referenc e value is additionally displayed as peak and rms value.

CF 978.3 MHz

ef Lvl 0 dBm

Bit No.

FM RELATIV: -45.21 dB PK/2 -58 dB RMS REF Deviation: 10.00 kHz Pk 7.07 kHz RMS

SINAD 1 kHz: OFF AUDIO FREQ: 1.001 kHz FREQ ERROR: 101.1 Hz CARR PWR: 7.88 dBm FILTER: CCITT DEEMPH 50us PRE DISP O N

AM: 1.031 % PK/2 PM 1.011 rad PK/2

Symbol Table

MODULATION SUMMARY FM

Example: AVERAGE/ HOLD ON:

ef Lvl 0 dBm

Bit No.

FM RELATIV: -45.21 dB PK/2 HLD -58 dB RMS AV REF Deviation: 10.00 kHz Pk HLD 7.07 kHz RMS AV

SINAD 1 kHz: OFF AUDIO FREQ: 1.001 kHz AV FREQ ERROR: 101.1 Hz AV CARR PWR: 7.88 dBm FILTER: CCITT DEEMPH 50us PRE DISP O N

AM: 1.031 % PK/2 PM 1.011 rad PK/2

Symbol Table

MODULATION SUMMARY FM

DEMOD BW: 100 kHz

CF 978.3 MHz DEMOD BW: 100 kHz

REAL TIME ON MOD SUMMARY FM

ANALOG DEMOD

REAL TIME ON

MOD SUMMARY FM ANALOG DEMOD

1066.4317.02 2.4-16 E-2

FSE-B7 Analog demodulation methods

SUMMARY SETTINGS

AVERAGE/

HOLD ON

SUMMARY

SETTINGS

AVERAGE / HOLD ON

SWEEP COUNT

REL UNIT

INDICATION

ABS REL

SET REFERENCE

MEAS->REF

SINAD 1kHz

ON OFF

The

AVERAGE/HOLD ON

The

SUMMARY SETTINGS

softkey opens up the submenu for conf iguration of the sum m ary of all num eric measured values.

softkey permits to average all display values obtained in the number of sweeps defined under Sweep Count except for the Pk values with Single Sweep (the disp lay in the modulation summary,

is indicated after the units).

No of Measurements

appears

SWEEP COUNT

REL UNIT

dB %

The Pk values are displayed in the Pk Hold m ode ( display

Hold

after the Pk

units). In the case of a restart, the Pk values and AV values ar e res et by m eans of

Single Sweep or by switching

The

SWEEP COUNT

softkey sets the number of sweeps used to determ ine

TRACE AVERAGE/HOLD ON

off and on.

the average or PK Hold values (see also the corresponding softkey in analyzer mode)).

The

REL UNIT dB/%

display (

INDICATION REL

softkey selects the unit (% and dB) with relative

) .

1066.4317.02 2.4-17 E-2

Analog demodulation methods FSE-B7

INDICATION

ABS REL

SET REFERENCE

MEAS-> REF

The

INDICATION ABS REL

default setting) and relative display ( relative display can be entered by means of

REF

softkey switches between absolute (

REL

). The reference value for the

SET REFERENCE

MEAS

ABS

→

Only the main signal can be displayed in relative mode, the other signals are indicated in absolute display in any case.

For relative indication, the default unit is dB and can be changed f rom dB to % via the softkey

The

SET REFERENCE

REL UNIT%

softkey opens up a field for input of a reference

modulation (for main signal). The peak value of the modulation is to be entered. The rm s ref erence value

will then be peak value/√2.

The

MEAS→REF

softkey is used to represent the current absolute measured values of the main modulation signal (+-PK/2 and RMS) as reference values for the relative display.

SINAD 1kHz

ON OFF

REAL TIME ON only.

The

SINAD 1 kHz ON

softkey activates the SINAD measurement for the

main modulation signal. Irrespective of the signal applied, the m ain modulation signal is compared

with the main modulation signal which is filtered by a 1-kHz notch filter. T he display unit is dB.

When a signal m odulated with 1 kHz is applied, the SINAD value is thus displayed correctly. Default setting is

With

REAL TIME OFF

SINAD 1 kHz OFF

(no real-time demodulation) no SINAD measurement

is possible, the softkey cannot be operated.

1066.4317.02 2.4-18 E-2

FSE-B7 Analog demodulation methods

SUMMARY MEAS TIME

REAL TIME ON only.

The

SUMMARY MEAS TIME

softkey opens up a field for entering the measuring time (as well as the measured value update rate) for the numerical measured values of the modulation summary.

Default setting is 100 ms Thus, with a stationary modulation frequency of 30 (typ. 20) Hz, peak values

and rms value can be determined correctly. The measured values are updated at least every 100 ms, ie max. 10x/s. With a measur ing tim e of 1 s and a st ationary modulation f r equency of up to

5 Hz peak values and rms values can be determined correctly. The measured values are updated every second, ie max. 1x/s. In both cases, the peak values are measured continuously, the time

constant of the rms detector is adapted accordingly.

SUMMARY MEAS TIME

100 ms 1 s

REAL TIME ON OFF

SENSITIV AF OUTPUT

The

REAL TIME ON/OFF

softkey switches real time demodulation on or off.

For demodulation bandwidths ≤ 200 kHz, real-time demodulation can be switched on or off. (Off is default status).

Demodulation bandwidths > 200 kHz do not allow real-time modulation.

REAL TIME ON only.

The

SENSITIV AF OUTPUT

real-time modulation. Depending on

softkey sets the scaling of the AF output f or

MEAS RESULT

(AM, FM or PM signal), an input field appears, where the modulation amplitude is to be entered so that the dynamic range of the AF output is fully utilized. (Peak voltage 1V):

m[%] FOR FULL SCALE SIGNAL

FM DEV FOR FULL SCALE SIGNAL

100

PM DEV FOR FULL SCALE SIGNAL

SENSITIV AF OUTPUT

also has an effect on the volume of the

loudspeaker and on the headphones output.

1066.4317.02 2.4-19 E-2

Analog demodulation methods FSE-B7

VOLUME

REAL TIME ON only

The

VOLUME

(loudspeaker and headphones output) according to the slope of the AF output.

REAL TIME OFF

With off.

softkey sets the volume of the demodulated signal

(no real-time demodulation) the outputs are switched

Note: If the modulation depth / deviation is very small, the scaling of

the AF output (softkey

SENSITIV AF OUTPUT

) is to be

matched to achieve a usable volume. On the other hand, the modulation depth / deviation must not

be greater than the full-scale setting under SENSITIV AF OUTPUT, or a distorted signal will be obtained at the loudspeaker/headphones output even with the volume reduced.

1066.4317.02 2.4-20 E-2

FSE-B7 Analog demodulation methods

2.4.2.3 Triggering with Analog Demodulation - Softkey TRIGGER or Hardkey TRIGGER

Submenu:

TRIGGER

SWEEP

TRIGGER

SWEEP

RBW

VB W

SW T

COUPLING

CONFIGURATION MODE - VECTOR ANALYZER - ANALOG DEMOD

TRIGGER

FREE RUN

VIDEO

EXTERN

AF SIGNAL

TRIGGER OFFFSET

SLOPE POS NEG

The

TRIGGER

softkey as well as the

permit to call up the menu for setting the trigger.

TRIGGER

hardkey

FREE RUN

VIDEO

EXTERN

The

FREE RUN

softkey activates a measurement without trigger. After a measurement has been terminated, data acquisition for a new measurement takes place immediately.

REAL TIME OFF only

The

VIDEO

softkey starts the meas urement by means of the video voltage

of the analog path of the spectrum analyzer. For this purpose, the analog video voltage of the spectrum analyzer is analyzed parallel to the vector signal analyzer.

Video triggering is of particular use f or frequency settling m easurem ents on synthesizers.

Video triggering requires the trigger threshold to be entered. It is identical with the trigger threshold of the spectrum analyzer. The trigger threshold is entered numerically into the data input field in % of the last grid that was active in spectrum analysis mode.

The appropriate value for the trigger threshold can be determined in the spectrum analysis mode.

REAL TIME OFF only

The

EXTERN

softkey activates triggering via an external voltage in the

range from - 5 V to + 5 V at the BNC connector EXT TRIGGER / GATE (rear panel). Enter the desired value in the data input field.

1066.4317.02 2.4-21 E-2

Analog demodulation methods FSE-B7

SIGNAL

TRIGGER

OFFSET

SLOPE

POS

NEG

The

AF SIGNAL

softkey opens up a data input field where the level of the AF signal is entered as the trigger level for display of the time signal.

The AF trigger level is entered in %, Hz, deg or rad according to the current demodulation AM, FM or PM (in the case of AM DC in the curr ent absolute level unit).

Triggering on the AF signal is similarly possible with

REAL TIME ON/OFF.

REAL TIME OFF only

The

TRIGGER OFFSET

softkey opens up an input window for entry of the

desired offset with video trigger or external trigger (only with ). The softkey cannot be operated with

REAL TIME ON

and

REAL TIME OFF

in conjunction with AF trigger.

The trigger offset

is used to determine the start of data acquisition relative to the trigger event. Both positive values for a trigger delay and negative values for a pretrigger are permissible.

The input is made in absolute tim e irrespective of the scale select ed for the X-axis.

The

SLOPE POS/NEG

softkey determines the trigger edge for triggering y means of the video signal, AF signal or external trigger. The measurement run is started on a positive or negative edge of the trigger signal. W ith free-running trigger (

FREE RUN

), the setting is not of

any significance.

1066.4317.02 2.4-22 E-2

FSE-B7 Analog demodulation methods

2.4.2.4 Setting the Display Range and the Scaling Softkey RANGE or Hardkey RANGE

The menu for setting the range differs from that in the signal analysis mode. Submenu:

RANGE

LEVEL

REF

RANGE

Y PER DIV

CONFIGURATION MODE - VECTORANALYZER - ANALOG DEMOD

RANGE SCALE

The

RANGE

softkey as well as the used to call up a menu, which contains all the parameters important for the vertical axis (y-axis) and

Y PER DIV

REF VALUE

Y AXIS

REF VALUE

x AXIS

REF VALUE

POSITION

SENSITIV

AF OUTPUT

VOLUME

SCALE

UNIT

The

Y PER DIV

the horizontal axis of the screen display of the AF signal, such as reference values, scaling, etc.

In addition, with real-time demodulation, the slope of the AF output as well as the volume of the loudspeaker or headphones connector can be set here.

softkey indicates the vertical scaling in the current unit.

Hz or % are set for AM or FM, respectively. PM permits to choos e between the units deg and rad (default status: rad).

RANGE

hardkey are

REF VALUE

Y AXIS

REF VALUE

POSITION

For the relative value display of the modulation sum mary, it is possible to choose between % and dB (default setting dB).

The

REF VALUE Y AXIS

softkey prompts the user to enter the reference

value for the Y-axis of the diagram. The reference value is entered in the respective display unit (see

The

REF VALUE POSITION

softkey opens up an input window, in which

UNIT

reference value positions deviating from the default setting are set.

REF VALUE POSITION

determines the position of the ref erence value. It is

normally 50 % when the AF signal is displayed.

1066.4317.02 2.4-23 E-2

Analog demodulation methods FSE-B7

SENSITIV AF OUTPUT

VOLUME

The

SENSITIV AF OUTPUT

(sensitivity AF output) softkey is used to set

the scaling of the AF output with real-time demodulation. Depending on

MEAS RESULT

(AM, FM, or PM signal), an input field appears , where the modulation amplitude is to be entered at which the dynamic range of the AF output is fully utilized. (Peak voltage 1V):

m[%] FOR FULL SCALE SIGNAL

FM DEV FOR FULL SCALE SIGNAL

100

PM DEV FOR FULL SCALE SIGNAL

SENSITIV AF OUTPUT

also affects the volum e of the loudspeak er and the

headphones output.

REAL TIME ON only

The

VOLUME

softkey sets the volume of the demodulated signal (loudspeaker and headphones output) according to the slope of the AF output.

REAL TIME OFF (

With

no real-time demodulation) the outputs are switched

off.

Note: If the modulation depth / deviation is very small, the scaling of

the AF outputs (Softkey SENSITIV AF OUTPUT) is to be matched to achieve a usable volume.

On the other hand, the modulation depth / deviation must not be greater than the full-scale setting under SENSITIV AF OUTPUT, or a distorted signal will be obtained at the loudspeaker/headphones output even with reduced volume.

1066.4317.02 2.4-24 E-2

FSE-B7 Analog demodulation methods

Submenu:

SCALE

UNIT

CONFIGURATION MODE - VECTOR ANALYZER - ANALOG DEMOD - RANGE

SCALE

UNIT

Y UNIT

LOG[dB]

Y UNIT

INEAR

UNIT DEG

The

SCALE UNIT

softkey calls up a subm enu for setting

the unit of the Y-axis . The units offered depend on the signal displayed.If a

marker is s witched on, the marker results are output in the current scale units.

ANALOG DEMODULATION,

With

the following Y-units are possible according to the type of modulation AM: AM[%],

UNIT RAD

FM: Hz, PM: rad (default setting) or deg.

Y UNIT dBm

Y UNIT VOLT

(With AM and FM, the units cannot be selected). With tim e display of the AM signal and

AF COUPL’G DC

selected, the AM-demodulated signal is not standardized, but scaled in absolute levels.

Y UNIT WATT

X UNIT

TIME

Possible units are dBm, V and W. The default unit is dBm.

X UNIT SYMBOL

1066.4317.02 2.4-25 E-2

Analog demodulation methods FSE-B7

2.4.2.5 Sweep Menu with Analog Demodulation - Softkey SWEEP TIME or Hardkey SWEEP

Submenu:

SWEEP TIME

oder

SWEEP

TRIGGER

SWEEP

RBW

VBW

SWT

COUPLING

CONFIGURATION MODE - VECTORANALYZER - ANALOG DEMOD

SWEEP

CONTINOUS

SWEEP

SINGLE

SWEEP

SWEEP COUNT

SWEEP

TIME

The

SWEEP

key calls up a menu, which permits to determine the type of measurement - single measurement or continuous measurement - and the length of the measurement results to be displayed in terms of time.

CONTINOUS

SWEEP

SINGLE

SWEEP

The

CONTINUOUS SWEEP

softkey starts a continuous measurement in accordance with the trigger condition and the selected test settings. Triggering is followed by data acquisition first and then by evaluation and display on the screen.

If, with split screen display, vector analysis mode is used fo r measurement in both windows, the data in the measurement RAM are used for both evaluations.

The

SINGLE SWEEP

softkeystarts n measurements in accordance with the trigger settings. The number of measurement runs n is determined by means of It can be restarted by pressing the

SWEEP

SWEEP COUNT

softkey again.

. The measurement stops after n measur ements.

SINGLE SWEEP

CONTINUOUS

1066.4317.02 2.4-26 E-2

FSE-B7 Analog demodulation methods

5000

SWEEP COUNT

SWEEP

TIME

The

SWEEP COUNT

measurements is determined for the

softkey opens up an input field in which the number of

SINGLE SWEEP

. The number of measurements can be selected between 0 and 32767. If averaging of the measur ed values is s et (

MARKER COUNT

SWEEP COUNT

RMS

to be found under the

also determines the number of measurements used for averaging.

= 0, 10 measured values are always used for floating

AVG/HOLD ON, MODULATION

MARKER SEARCH key

SWEEP

averaging. If

SWEEP COUNT

= 1, no averaging takes place.

>1, the average is taken of the set num ber of m easured

values.

SWEEP TIME

is used to define the time during which the demodulated signal is to be displayed. The maxim um time is determined by the demodulation bandwidth set and the buffer length for the demodulated signal, which is 5000 points with analog demodulation. Thus, the following settable maximum time is obtained:

SWEEP TIME

max

08.*( _ )DEMOD BW

[s]

RESULT LENGTH

A minimum of 10 points can be displayed, which means for the minimum settable time:

SWEEP TIME

min

08.*( _ )DEMOD BW

Example: With Demod BW 1kHz, the maximum and minimum time scale is as follows: TIME/DIV TIME/DIV

The

RESULT LENGTH

DEMODULATION

= 6.25 s

max

= 12.5 ms

min

softkey cannot be operated with

ANALOG

1066.4317.02 2.4-27 E-2

Analog demodulation methods FSE-B7

Example: Measurement of amplitude modulation

Measurement of a carrier modulated with 1 kHz, 50 % at 100 MHz, level 0 dBm

1. [PRESET] Default setting

2. [CENTER: 100 MHz] Frequency setting

3. [REF: REF LEVEL: +6 dBm] Level setting (the max. level of AM-modulated signals is 6 dB above the nominal level with 100 % AM).

4. [MODE: VECTOR ANALYSIS] Selection of vector analysis mode The FSE is in the analysis mode

DIGITAL DEMODULATION

5. [ANALOG DEMODULATION] Switch to analog demodulation. The AM-modulated signal appears on the display (display in the time domain, the default setting for [ demodulation bandwidth (analysis bandwidth) is 100 kHz in the default setting, i.e. audio signals up to max. 0.4* demodulation bandwidth can be demodulated.

6. [DEMOD BW: 30 kHz] The demodulation bandwidth is changed eg to 30 kHz

7. [TRIGGER:AF SIGNAL 0%] Trigger setting to achieve a stable display. The display of the AF signal at the left edge of the screen starts at 0 %.

ANALOG DEMODULATION

(default setting).

] is AM-SIGNAL). The

8. [SWEEP: SWEEPTIME 100 ms] Setting of the sweep time. The sweep time depends on the demodulation bandwidth and the sampling points provided (=5000 with analog demodulation). With a demodulation bandwidth of 30 kHz, the max. sweep time is 208 ms in the default setting.

9. [SEARCH: SUM MKR ON] Activating the summary marker for numeric trace evaluation.

1066.4317.02 2.4-28 E-2

FSE Digital Modulation Methods

2.4.3 Digital Modulation Methods

2.4.3.1 Diagram for signal processing

In modern mobile radio networks digital transmission methods are used to avoid the disadvantages of a transmission channel in mobile communication and to be able to serve more subscribers in the available frequency spectrum. The FSE offers all commonly used demodulators for digitally modulated signals. All modulation parameters for standard transmission methods can be loaded as required by the user. The FSE determines all relevant modulation parameters such as frequency, phase, amplitude and vector errors, etc. Measurements are carried out on continuous as well as pulsed signals such as TDMA signals. Bit patterns can be defined to be able to trigger to known bit sequences like preambles or midambles. The demodulator requires neither a coherent carrier nor a symbol clock for demodulation. It comprises matched filters and synchronizes automatically to the carrier and to the symbol clock. Furthermore, the demodulator can generate the ideal I/Q signal from the demodulated bit stream and thus determine the errors of the analyzed signal.

For a correct demodulation of digital signals, a number of modulation parameters in addition to the modulation mode has to be specified for the signal to be analyzed. The most important are the symbol rate and the input filter. And in addition, the frequency of the FSE (approx. 2% of the symbol rate) has to be tuned exactly to the frequency of the signal to be analyzed.

The bandwidth for demodulation is a function of the symbol rate and the selected oversampling method (

POINTS PER SYMBOL

PER

SYMBOL

is reduced, fewer points are used in the display. The demodulation bandwidth for 1, 2 and 4 points per symbol is 3.125 times the symbol rate, with 8 points per symbol 6.5 times and for 16 points per symbol 13 times. It should be ensured that no modulation spectrum of adjacent signals is within the displayed range during demodulation, as this may introduce errors in the measurement of modulation parameters. If required, check for correct settings in the analyzer mode. The block diagram below shows the digital demodulator and its measurement capabilities:

). At least 4-fold oversampling is performed. If the number set under

POINTS

Digital

6,4 MHz/

1,4 MHz

I/Q Measure Signal

I/Q-R eferen ce Sig nal

Bit Strom

Filter

Digital

Error

Calcutation

Digital

Filter

I/Q Amplitude Error I/Q Phas e Error I/Q Error ERROR VECTOR MAGNITUDE

Symbol Table

Capture

RAM

Graphi k-

Processing

Pulse

I/Q

Display

Digital

Demodulation

SYNC SEARCH

I/Q Measured Si ignal I/Q Referen ce Signal Bits for Symbo l Tabl e

Fig. 2.4-4 Block diagram for signal processing during digital demodulation

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Digital Modulation Methods FSE

2.4.3.2 Symbol Mapping

The following types of symbol mapping are used for representing the results in the vector and constellation diagrams (PSK, MSK, QAM) and for the time/frequency representations with FSK modulation. The symbols are always in the binary code (MSB at left).

2.4.3.2.1 Phase Shift Keying (PSK)

With these modulation types, the symbol represents the absolute phase of the received signal at the decision time. The following representations are given:

• a constellation diagram containing all symbols

• a table containing the symbol designations and the associated reference phases

With this type of phase modulation, transitions from any symbol to any other in the constellation diagram are permitted.

BPSK QPSK (WCDMA)

Symbol Phase 0 0 1 Π

QPSK (QCDMA FWD; WCDMA; APCO25) 8PSK OQPSK (QCDMA REV)

Symbol Phase 00 Π/4 01 3Π/4

0001

11 5Π/4 10 7Π/4

100

Q 010

Symbol Phase 00 Π/4 01 3Π/4

0001

11 5Π/4 10 7Π/4

Symbol Phase 000 0Π/4 001 1Π/4 010 2Π/4

001011

011 3Π/4 100 4Π/4 101 5Π/4 110 6Π/4

000

111 7Π/4

101 111

110

Fig. 2.4-5 Symbol mapping - phase shift keying

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FSE Digital Modulation Methods

3PI/8-8PSK (EDGE)

For these modulation methods the digital information is NOT coded in the phase transitions but in the absolute position of the constellation diagram. The constellation diagram consists of 16 points. For each

symbol transition, an offset of 3pi/8 is inserted counterclockwise. The symbol allocation in the constellation diagram is thus only valid for the first symbol of the data record. Five symbol transitions with an offset of 3pi/8 each is given as an example. The modulated symbol "111" remains constant. This phase offset is taken into account during decoding and the display of symbols.

Phase

011

111

Symbol 000 001 010 011 100 101 110 111

3Π/8 4Π/8 2Π/8 1Π/8 6Π/8 5Π/8 7Π/8 0Π/8

001

000

3Π/8

Q 010

3Π/8

3Π/8 3Π/8

101

100

Fig. 2.4-6 Symbol mapping - phase shift keying - EDGE

110

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Digital Modulation Methods FSE

2.4.3.2.2 Differential PSK

When using differential phase modulation, the symbol is the result of the phase difference between the current and the previous decision point. The absolute position of the pointer at the decision time is therefore not relevant. In the following diagrams, the phase transitions are shown, as examples, in the first quadrant, while the pointers point to the constellation point relevant for the current decision time. The signal is demodulated such that the decision times coincide with the constellation points. The following representations are given:

• a constellation diagram containing all permissible symbol transitions

• a table containing the symbol designations and the associated phase differences

The absolute phase of the signal is not relevant for the symbol decision.

PI/4 DQPSK

The positions of the permissible constellation points is as with 8PSK. With this technique, only the phase transitions given in the tables are permitted.

NADC, PDC, PHS, TETRA, APCO25, PWT TFTS

Phase

Symbol difference 00 Π/4 01 3Π/4 10 -Π/4 11 -3Π/4

Phase Symbol difference 11 Π/4 01 3Π/4 10 -Π/4 00 -3Π/4

D8PSK

The positions of the permissible constellation points is as with 8PSK. With this technique, transitions to all 8 constellation points possible are permitted.

Phase

001

011

010

110 111 101

Symbol difference 000 0*Π/4 001 1*Π/4

000

011 2*Π/4 010 3*Π/4 110 4*Π/4 111 5*Π/4

100

101 6*Π/4 100 7*Π/4

Fig. 2.4-7 Symbol mapping - differential phase modulation

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FSE Digital Modulation Methods

2.4.3.2.3 Frequency Shift Keying (FSK)

When working with FSK demodulation, a frequency/time diagram will be displayed instead of the constellation and vector diagrams. The symbol decision is based on the signal deviation at the decision times.

2FSK (DECT, CT2; FLEX16_2; FLEX32_2)

With 2FSK, the symbol decision is taken by a

simple frequency discriminator with the following decision threshold:

f = f

Tmid

"1" for f f

Symbol =

MID

 

"0" for f f



= instantaneous frequency = decision threshold = middle frequency of analyzer

≥







4FSK (ERMES; MODACOM; APCO25; FLEX32_4; FLEX64_4)

With 4FSK the symbol decision is taken by a

frequency discriminator using three decision thresholds derived from the operating parameter

REF_DEVIATION:

f = f -

T1 MID

f = f

T2 MID

f = f +

T3 MID

Symbol =

1 3

 

 

 



REF_DEVIATION

⋅

REF_DEVIATION

⋅

for f f

≥

ET3

for f f

≤<

ET3

for f f

≤<

T1 E

for f < f

IT1

 

 

 



"1"

"0"

"11"

"10"

"01"

"00"

REF_DEVIATION

fff

,, = decision thresholds

T1 T2 T3

MID

= instantaneous frequency

= middle frequency of analyzer

Fig. 2.4-8 Symbol mapping - FSK demodulation

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Digital Modulation Methods FSE

2.4.3.2.4 Minimum Shift Keying (MSK), CDPD

Phase

Fig. 2.4-9 Symbol mapping - minimum shift keying (MSK)

DMSK (and the derived GSMK) uses additional difference coding of two subsequent symbols. Static symbol mapping therefore does not exist.

Symbol difference 0 -Π/2 1 Π/2

2.4.3.2.5 Quadrature Amplitude Modulation (QAM)

With the QAM technique, the symbols are counted linearly from right to left and from top to bottom (linear mapping).

Note: For reliable demodulation make sure the available symbols are utilized. If only some of the

symbols or only the symbols in one quadrant are utilized, demodulation errors may occur.

0000000100100011

0100010101100111

1011 1010 1001 1000

1111 1110 1101 1100

Fig. 2.4-10 Symbol mapping - 16QAM

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FSE Digital Modulation Methods

2.4.3.3 Selecting the Digital Demodulators

Submenu:

DIGITAL

DEMOD

CONFIGURATION MODE - VECTOR ANALYZER

The

DIGITAL DEMOD

DIGITAL

DEMODULATION

BPSK QPSK DQPSK PI/4DQPSK OQSK 8PSK D8PSK

3π/8-8PSK MSK DMSK 2FSK 4FSK 16QAM

4FSK APCO25

softkey opens a list of all available demodulators.

Demodulators are provided for the two-, four- and eight-level PSK modulation modes BPSK, QPSK and 8PSK. For QPSK and 8PSK demodulation, the demodulators for differential signals DQPSK and D8PSK can be selected additionally.

Demodulators are also availabe for the special versions of QPSK modulation, such as differential QPSK with π/4 phase offset (π/4-DQPSK) and offset QPSK (OQPSK).

QPSK is used, for instance, by the IS95- CDMA for modulating signals from the base station to the mobile, OQPSK for signals from the mobile to the base station. The American TDMA system NADC (IS54) uses π/4-DQPSK for digital signal transmissions.

For higher-level modulation modes the demodulator for 16QAM is available. MSK (minimum shift keying) demodulators pertain to the group of continuousphase demodulators. MSK with Gaussian filters (GMSK = Gaussian minimum shift keying) is used for the European mobile radio systems GSM and DCS1800 or PCS1900 in the USA. For correct bit detection for GSM, DCS 1800 and PCS 1900 and 1800 the MSK demodulator with additional differential decoding (DMSK) should be activated.

For FSK (frequency shift keying modulation, two-level (2FSK) and four-level (4FSK) demodulators can be selected.

2FSK modulation methods are used for instance for the digital cordless telephone to DECT standard, 4FSK for the paging system to ERMES standard.

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Digital Modulation Methods FSE

2.4.3.4 Standard Settings

To simplify the selection of parameters when standard transmission methods are used, standard setups are available in the FSE. All modulation parameters and the width of the display range are set automatically. The following table shows available standards and respective settings. For the GSM, DCS1800 and PCS 1900 standards the sync pattern GSM_BTS0 with the associated synchronization offset of 61 symbols is preset in addition. When selecting the NADC standard, the instrument is set to the burst of the base station with a slot length of 162 symbols. When selecting the NADC FORWARD CH standard, the instrument is set to the non-burst signal of the base station with a slot length of 162 symbols. For the burst of the mobile station, the standard length NADC REVERSE CH must be set. For the DECT standard the sync pattern of the fixed part DECT_FP is preset, the sync offset is set to 0. When selecting the TETRA standard, the sync pattern Tetra_1 is preset, the sync offet is preset to 122.

Sync pattern and sync offset become active be switching

FIND SYNC

(menu

SWEEP TRIGGER

) on.

Note: The pager standards ERMES and FLEX (2FSK and 4FSK modulation) feature modulation

filters with increased bandwidth (B*T> 1). This means that with normal oversampling (4 points per symbol) there is an intolerable bandwidth restriction which causes a distinctly higher demodulation error probability. Therefore the number of points per symbol is preset to 8 when the ERMES standard is selected and to 16 when the FLEX standard is selected.

Attention: In case of departures from the preset value (which may happen automatically when

increasing the frame length or result length) there is a higher system error probability.

Submenu:

DIGITAL

STANDARDS

CONFIGURATION MODE - VECTOR ANALYZER

DIGITAL

STANDARDS

PDC UP

PDC DOW N

NADC

FWD CH

NADC

REV CH

DIGITAL

STANDARDS

IS95-CD MA

FWD CH

IS95-CDMA

REV CH

DIGITAL

STANDARDS

CT2

APCO25

ERMES

MODACOM

FLEX16_2

The

DIGITAL STANDARDS

softkey calls up a submenu of available standard setups.

If one of the following modulation parameters is modified, any digital standard that may be selected is switched off automatically:

• Symbol rate

• Measurement filter

FLEX32_2

• Reference filter

DECT

FLEX32_4

• α/BT

PHS

PWT

TETRA

TFTS

EDGE

GSM

FLEX64_4

APCO25 C4FM

APCO25 CQPSK

CDPD

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FSE Digital Modulation Methods

Table 2.4-1 Standard settings

Modulation/ Standard

IS95-CDMA FWD CH QPSK IS95-CDMA REV CH OQPSK EDGE 8π/8-8PSK GSM, (DCS1800, PCS 1900) MSK NADC FWD CH*) π/4 DQPSK NADC REV CH π/4 DQPSK PDC DOWN π/4 DQPSK PDC UP π/4 DQPSK

PHS π/4 DQPSK CDPD MSK 19.2 kHz NONE GAUSSIAN 0,5 -- -- -- 4

DECT 2-FSK 1152 kHz NONE GAUS S IAN 0,5 VIDEO

TETRA π/4-DQPSK CT2 2-FSK ERMES 4-FSK 3.125 kHz NONE BESSEL 1_25 -- -- -- 8 MODACOM 4-FSK FLEX 16_2 (FLEX 1600) 2FSK FLEX 32_2 (FLEX 3200) 2FSK FLEX 32_4 (FLEX 3200 4-FSK FLEX 64_4 (FLEX 6400) 4FSK PWT WCPE π/4 DQPSK TFTS

π/4 DQPSK**) APCO25 C4FM 4.8 kHz NONE RAISED COS 0.2 -- -- 8 APCO25 CQPSK 4.8 kHz APCO25FM RAISED COS 0.2 -- -- 4

Symbol rate Measureme

nt filter

1.2288 MHz IS95_FM IS95_FR -- -- -- -- 4

1.2288 MHz IS95_FR I S95_RR -- -- -- -- 4

270.833 kHz EDGE_MES EDGE_REF -- BURST

270.833 kHz NONE GAUSSIAN 0,3 BURST

24.3 kHz ROOT RAISED COS

21 kHz ROOT

RAISED COS

21 kHz ROOT

RAISED COS

192 kHz ROOT

RAISED COS

18 kHz ROOT

RAISED COS

72 kHz NONE GAUSSIAN 0,5 BURST

4.8 kHz ROOT RAISED COS

1.6 kHz NONE BESSEL 2_44 -- -- -- -- 16

3.2 kHz NONE BESSEL 1_22 -- -- -- -- 16

1.6 kHz NONE BESSEL 2_44 -- -- -- -- 16

3.2 kHz NONE BESSEL 1_22 -- -- -- 16

562.5 kHz ROOT RAISED COS

22.1 kHz ROOT RAISED COS

Reference

filter

RAISED COS 0,35 SYNC RAISED COS 0,35 BURST RAISED COS 0,5 SYNC RAISED COS 0,5 BURST RAISED COS 0,5 BURST

RAISED COS 0,35 BURST

RAISED COS 0,2 -- -- -- 4

RAISED COS 0,5 BURST RAISED COS 0,4 BURST

AlphaBTSynchro-

nization

SEARCH SEARCH SEARCH SEARCH SEARCH SEARCH SEARCH

TRIGGER + BURST SEARCH

SEARCH SEARCH

Sync

Pattern

EDGE_BT0061 4 GSM_BTS0 61 4 NADC_S1 0 4 NADC_S1 8 4 PDC_S1 57 4 PDC_S1 57 4 PHS_DO1 32 4

DECT_FP 0 4

TETRA_1 122 4 CT2_CFP 0 4

WCPE_FP1 0 4 TFTS_G1 0

SYNC OFFSET

Points/

symbol

*) The standard setting is matched t o t he slot of the NADC base stati on. As the base station doesn’t burst, the FIND BURST

function is disabled.

**) W hen selecting the TFTS standard, the special bit decoding is made according to the TFTS s t andard.

The standard settings are called up by means of the DIGITAL STANDARD softkey.

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Digital Modulation Methods FSE

2.4.3.5 Selecting Modulation Parameters for Digital Demodulation

Submenu:

MODULATION PARAMETERS

CONFIGURATION MODE - VECTOR ANALYZER

MODULATION PARAMETERS

SYMBOL

RATE

SIDE BAND NORM INV

MEAS

FILTER

REFERENCE

FILTER

ALPHA/BT

FSK REF

DEVIATION

NORMALIZE

ON OFF

The

MODULATION PARAMETERS

setting of the modulation parameters.

softkey calls up a submenu for

SYMBOL

RATE

SIDEBAND

NORM INV

The

SYMBOL RATE

soft key opens a window for entering the symbol rate of the

digitally modulated signal to be measured. The symbol rate is a function of the bit rate determined via the modulation level and

corresponds to the baud rate. With QPSK, for instance, the symbol rate corresponds to half the bit rate (= 2 bits per symbol). Symbols are only valid while the signal is evaluated by the receiver. The time of demodulation is the point of decision. The demodulator of the FSE uses the set symbol rate to find the points of decision.

To be able to select the correct symbols, the symbol rate has to be entered exactly. The more complex (high-level) the modulation method, the more critical the exact definition of the symbol rate. An inaccurately defined symbol rate causes demodulation errors. The settings below should also be observed for selecting the symbol rate:

• Maximum possible symbol rate is 2.133 MHz.

• The number of points per symbol is limited to 8 for symbol rates >200 kHz and to

4 for symbol rates >400 kHz.

The

SIDE BAND NORM / INV (INVERTED)

demodulates and inverts the

signal received. Thus, with FSK demodulation, the frequency states are inverted, and, with

non-FSK modulation, the I and Q signal are inverted. Default status is

SIDEBAND NORM

(normal).

1066.4313.02 2.4-38 E-5

FSE Digital Modulation Methods

MEAS

FILTER

REFERENCE

FILTER

The

MEAS FILTER

softkey selects the input filter for the signal to be

measured. The required filter is selected in a table:

MEAS FILTER

None Raised Cos Root Raised Cos Gaussian

apco25fm edge_mes edge_ref bess1_22 bess1_25 bess2_44 is95_fm is95_fr is95_rm is95_rr

Further information is given in the description of the

REFERENCE FILTER

softkey.

The

REFERENCE FILTER

softkey selects the filter for the ideal reference signal for detecting modulation errors at the baseband level. The required filter is selected in a table:

REFERENCE FILTER

Raised Cos Root Raised Cos Gaussian

apco25fm edge_mes edge_ref bess1_22 bess1_25 bess2_44 IS95_fm IS95_fr IS95_rm IS95_rr

Predefined filters are the squarewave filter (only for setting

FILTER:NONE

), the raised cosine filter, the root raised cosine filter and the

MEAS

Gaussian filter. Cosine filters are generally used for PSK modulation, Gaussian filters by MSK and FSK modulators.

The filter parameters are set via

ALPHA/BT

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Digital Modulation Methods FSE

The digital demodulator of FSE generates two signals at the I/Q level, the signal to be measured ( (

REFERENCE SIGNAL

MEAS SIGNAL

) and the reference signal

Frequency and symbol synchronization

Symbol detector

Amplitude/ phase correction

Reference signal generator

Meas filter

Reference filter

Test signal (I/Q)

Reference signal (I/Q)

Bits for symbol table

The signal to be measured is present at the RF input after demodulation. The reference signal is the signal that would be obtained in the case of an ideal RF signal. A separate filter is provided for the signal and the reference signal. For digital transmissions, filtering can be carried out at the transmitter or receiver end or be split up between both. The filter at the receiver is the measurement filter. The reference filter is used for the total system. Depending on the configuration of filters, the following combinations can be used:

Filters of transmission system Filters to be selected

Transmitter Receiver MEAS FILTER REFERENCE FILTER

Root-raised cos Root-rai sed cos Root-raised cos Raised cos Raised Cos none none Raised cos Gaussian none none Gaussian

If no modulation filter is provided in the transmitter, it may also be useful to employ a RAISED COS or GAUSSIAN filter as measurement filter.

However, the non-existing band limiting at the FSE input may cause unwanted aliasing products in the vector analyzer mode, which might impair the measurement. A measurement without reference filter is not possible!

1066.4313.02 2.4-40 E-5

FSE Digital Modulation Methods

ALPHA/BT

If an input filter is used for demodulation or a filter for generating the reference signal, the filter characteristic has to be determined by means of

ALPHA/BT

filters the product of the symbol period T and bandwidth B ( The A

the cosine filters or the bandwidth/symbol period product filters is entered. All filters are computed up to a length of 16 symbols.

Permissible input values are 0.2 to 3 in steps of 0.05. The value for

ALPHA/BT ALPHA

values should be used for measurements with FSE as higher demodulation errors could otherwise occur.

ALPHA/BT >1

For symbol is usually not sufficient. In this case it is recommended to set the number of points per symbol to 8 or 16. See also the note under DIGITAL STANDARDS. filter (cosine filter). It is also designated as roll-off factor or bandwidth factor. The greater ALPHA, the greater is the bandwidth occupied by the digitally modulated signal relatives to the theoretical minimum. In digital transmission systems typical bandwidth factors of 0.25 to 0.5 are used, ie the occupied bandwidth is 25% to 50% larger than the theoretical minimum. The bandwidth/time product factor of Gaussian filters.

. With Nyquist filters

LPHA/BT

or BT are determined by the digital transmission system. These

soft key opens a window where the roll-off factor (

applies to the measurement and to the reference filter. Values for

, the demodulation bandwidth with sampling of 4 points per

ALPHA

describes the transmission characteristic of a Nyquist

ALPHA

has to be specified, with Gaussian

ALPHA

for the Gaussian

describes the characteristic or the bandwidth

) for

FSK REF

DEVIATION

The

FSK REF DEVIATION

deviation for FSK demodulation. FSK deviation is defined as the (unilateral) deviation from the center

frequency occurring in the case of modulation with constant 0 or 1 sequences, ie the stationary value.

For 4FSK, the modulation deviation is the deviation from the center frequency for the bit sequences causing maximum frequency deviation. The reference deviation is used for computing the deviation error in

NORMALIZE ON

mode

softkey opens a window for entering the reference

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Digital Modulation Methods FSE

NORMALIZE ON OFF

The

NORMALIZE ON/OFF

softkey has the following effect: The measurement result in the vector and constellation diagram is always normalized to a circle, the radius of which corresponds to the mean distance between the center of the circle and the mid-points (of all groups of sampling values). This circle is defined as a unit circle with the radius 1.

Softkey

NORMALIZE ON

shifts the center of the unit circle by the I/Q offset to

the center for the group mid-points.

NORMALIZE ON

r=1

is the default state:

Center for group mid-points

Diagram in the case of

r=1

Center for group mid-points

Mid-point of a group of sampling values

NORMALIZE OFF

I/Q Offset

Mid-point of a group of sam p ling va lues

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FSE Digital Modulation Methods

2.4.3.4 Selecting Measurement Results for Digital Demodulation

After entering all modulation parameters the required measurement is selected using the

RESULT

softkey. The contents of the trace memory (magnitude), the demodulated measurement

MEAS

signal, the reference signal, i.e. the ideal signal derived from the measurement signal, or the error signal can be displayed as the measurement res ult. The I/Q error and the vector error are the two possible error signals. A table is available listing all errors together with the demodulated bits.

Submenu:

MEAS

RESULT

CONFIGURATION MODE - VECTOR ANALYZER

MEAS

RESULT

MAGNITUDE

CAP BUFFER

MEAS

SIGNAL

REFERENCE

SIGNAL

ERROR

SIGNAL

SYMB TABLE

/ERRORS

The

MEAS RESULT

different displays for the measured signal can be selected. The

MAGNITUDE CAP BUFFER, MEAS SIGNAL REFERENCE SIGNAL, ERROR SIGNAL TABLE/ERRORS

softkeys are selection switches, i.e. only one of the measurem ent results of fered c an be selected per sc reen. If two screens are available, (split-screen mode) a different measurement result can be displayed in each screen.

When the measurement signal, the reference signal and the error signal are displayed, submenus are called up by the corresponding softkeys and the associated parameter can be

softkey opens a submenu in which the

and

SYMB

set. Moreover, softkeys are available for setting the memory size,

MEMORY

SIZE

the number of bits to be demodulated and displayed.

FRAME

LENGTH

RESULT LENGTH

POINTS PER

SYMBOL

2.4.3.4.1 Magnitude of Capture Buffer

The capture buffer is the memory comprising the samples that are entered during the storage of measured values. These samples are used for demodulation but are retained over the complete measurement. A reason for this is the loss in the dynamic range during the synchronization and demodulation of the signal. For synchronization, an interpolation between the samples is necessary, for example, for determ ining the symbol decision point acc urately. Interpolation is always synonymous with a loss in the amplitude dynamic range. In case of synchronization, the signal has to be normalized. T he normalization is also linked with a loss in the dynamic range. When measuring the power ramping of a TDMA burst, a maximum dynamic range is required. This dynamic range is obtained when using the capture buffer for samples.

1119.5063.12 2.4-43 E-5

Digital Modulation Methods FSE

Submenu:

CONFIGURATION MODE - VECTOR ANALYZER

MAGNITUDE

CAP BUFFER

The

MAGNITUDE CAP BUFFER

signal in the capture buffer in the time domain. The

MAGNITUDE CAP BUFFER

MEAS RESULT

softkey indicates the magnitude of the

mode is therefore recommended in all cases where power ramping of TDMA bursts should be measured with a wide dynamic range. Timing will be accurate to les s than or equal to half a clock period of the sampling unit

Example:

A signal is sampled with 8 values per symbol. The maximum timing error of the TDMA burst synchronized to a bit sequence is 1/16, i.e. 6.25% of the symbol period

2.4.3.4.2 Measurement of Reference Signal

The FSE can display both the waveform of the m easur ement signal, which is derived f rom the s amples in the baseband, and that of the reference signal. T o this effec t, the m easurement signal is f iltered and synchronized to the carrier and the symbol clock. The I/Q off set and the amplitude reduction of the signal is compensated prior to the display. The reference signal is generated f rom the dem odulated bits by modulation down to the baseband. It is identical to the measurement signal freed of modulation errors and noise. The output formats for the measurement signal and the reference signal are identical. The output formats are different for FSK demodulation and thel other demodulation modes.

Output formats for non-FSK demodulation:

Submenu:

SIGNAL

REFERENCE

SIGNAL

CONFIGURATION MODE - VECTOR ANALYZER

MEAS

SIGNAL

MAGNITUDE

PHASE

FREQUENCY

REAL/IMAG

PART

EYE DIAG

[I]

EYE DIAG

[Q]

EYE DIAG

TRELLIS

POLAR [IQ]

VECTOR

POLAR [IQ]

CONSTELL

SYMBOL

DISPLAY

MEAS

SIGNAL

PHASE WRAP

EYE

LENGTH

OFF

MEAS RESULT

The

MEAS SIGNAL

SIGNAL

softkeys call up identical submenus.

and

REFERENCE

The output formats of the two signals can be selected there.

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FSE Digital Modulation Methods

The

MAGNITUDE

PHASE

MAGNITUDE

measurement or reference signal, which is normalized to 1, as a function of time and symbol.

The

PHASE

signal.

softkey displays the magnitude of the demodulated

softkey displays the phase of the measurement or reference

PHASE WRAP

FREQUENCY

REAL/IMAG

PART

OFF

The

PHASE WRAP ON/OFF

softkey activates/deactivates a phase shift.

The phase of a signal can have very high values due to the modulation. Therefore, scaling should be very coarse to display the phase over many bits. FSE therefore offers the phase to be shifted by means of the

WRAP ON/OFF

The FSE displays the phase in the range of ±180°. If the phase

softkey.

PHASE

exceeds +180°, for example, 360° is subtracted from the phase value so that >-180° is indicated. This avoids very high phase values to be displayed which would impair the reading accuracy.

OFF

The phase is not shifted. It is displayed within the range of the Y axis. Phase values above or below this range are cut off at the diagram edges.

The

FREQUENCY

softkey displays the time or symbol-dependent frequency response of the signal, i.e., the frequenc y-demodulated s ignal. The softkey is only available for MSK demodulation.

The frequency display is suitable for measuring the frequency deviation by using the markers.

The

REAL/

IMAG

PART

softkey calls up the display of the real and imaginary parts of the measurement or reference signal in separate diagrams. To this effect, the diagram is split up. The r eal part is displayed in the upper half whereas the imaginary part is displayed in the bottom half. The X ax is (which is scaled in time units or symbols) is identical for the two diagrams.

1119.5063.12 2.4-45 E-5

Digital Modulation Methods FSE

Fig. 2.4-11 Sim ultaneous display of inphase and quadrature component in a

single diagram (here: screen A in split-screen display)

EYE DIAG

[I]

EYE DIAG

[Q]

EYE DIAG

TRELLIS

The

EYE DIAG [I], EYE DIAG [Q]

the various eye diagrams:

and

EYE DIAG TRELLIS

softkeys select

• eye diagram for the inphase signal,

• eye diagram for the quadrature signal and

• trellis diagram.

The eye diagram is the representation of inphase and quadrature signal

EYE DIAG [I] or EYE DIAG [Q]

( symbol clock at the points of decision. The display range of the eye diagram (number of states on the time ax is) is determined by softkey

LENGTH

The individual traces of the eye diagram are s uperimposed on each other until the number of symbols spec ified with The successive trac es are the continuation of the trac e written last, i.e. the total trace is displayed in a folded form. T o obtain a com plete eye diagram, all the states of a signal have to be traced at least once. T he number of eyes vertically corresponds to the number of m odulation states les s 1. T he eye aperture is a measure for diff erentiating between two decision levels. A small eye apertures indicate a high, large eye apertures a sm all bit error rate.

) as a function of time. It is triggered by the

EYE

RESULT LENGTH

is attained.

1066.4313.02 2.4-46 E-5

FSE Digital Modulation Methods

The trellis diagram is used f or representing the states of c ontinuous-phase modulation methods (e.g. MSK). It indicates the phase versus time and

permits also phases above ±180° to be displayed. The trellis diagram is similar to the eye diagram in that measured traces ar e superimposed onto each other in the display until the number of symbols defined by

LENGTH

is attained.

For the FSE, the trellis diagram is particularly useful f or testing MSK and GMSK modulation. The symbols ar e spaced by 90°. A phase shift of +90 ° corresponds to logic 1, a shift of -90° to logic 0. A rising phase edge therefore indicates a logic 1, a falling edge a logic 0. Same as with the eye diagram, the width of the trellis diagram is defined by

EYE LENGTH

obtain a clear display, a minimum of 5 symbols should be selected as display width.

RESULT

. To

The number of P

OINTS PER SYMBOL

should be as high as possible to obtain a continuous trace in the eye diagram. 8 to 16 points are recommended.

Meas Signal Eye [Q] Demod DQPSK

200

-2

Ref Lvl 10 dBm

SYMBOLS

CF 890.195 MHz SR 15.3 kHz

Fig. 2.4-12 Eye diagram over 200 symbols of a DQPSK-modulated signal.

Display range is five symbols.

EYE

LENGTH

The

EYE LENGTH

softkey determines the display width of the eye diagram

in symbols. The number of symbols is entered in the field. At least one symbol length or two states are required for a com plete eye. To

be able to detect the errors particularly at the zero crossings, two to five symbols are recomm ended. The number of symbols is limited with

LENGTH

. In the case of

EYE LENGTH

RESULT LENGTH

RESULT

, however, the

signal versus time is displayed, the eyes are no longer visible.

1119.5063.12 2.4-47 E-5

Digital Modulation Methods FSE

POLAR [IQ]

VECTOR

POLAR [IQ]

CONSTELL

The

POLAR [IQ] VECTOR and POLAR [IQ] CONSTELL

softkey display the trace in the form of a polar diagram. In the vector diagr am, all the points are marked. In the constellation diagram only those at the points of decision.

In the I/Q diagram, the FSE displays the inphase component of the signal on the X axis, the quadrature component on the Y axis. Eac h trac e repr es ents a vector. The magnitude of the vector is the distance to the zero point, the phase is the angle between the positive X axis and the vector measured counterclockwise.

270

Phase

Magnitude = I + Q

180

Fig. 2.4-13 Vector in the I/Q diagram

In the vector diagram the num ber of points between the points of decision is determined with

POINTS PER SYMBOL

. For instance, if 5 points per symbol have been selected, every 5th point is a symbol at the point of decision. The other four points are intermediate values. The points of decision can be marked by selecting

DOTS

under

SYMBOL DISPLAY

. The constellation diagram displays only the measurement values at the points of decision.

Fig. 2.4-14 Constellation diagram (example QPSK)

1066.4313.02 2.4-48 E-5

FSE Digital Modulation Methods

The S

SYMBOL

DISPLAY

YMBOL DISPLAY

displayed trace. The desired form of highlighting can be selected from the table. Points of decision can be marked by vertical lines or by means of dots.

SYMBOL DISPLAY

ff Dots L

ines

With

off

selected, the points of decision are not marked. When selected, points are drawn on the trace and for constellation diagrams) ver tical lines are drawn between the X axis and the trace.

softkey marks the symbol decision points in the

Dots

are

Lines

, (except for vector and

For vector and constellation diagrams dots are inserted with For the constellation diagram dots are also displayed even in the This function is used for displaying the time characteristic of measurement

results, e.g. as an I/Q characteristic or error signal.

Output formats with FSK demodulation:

Submenu:

MEAS

SIGNAL

REFERENCE

SIGNAL

CONFIGURATION MODE - VECTOR ANALYZER - MEAS RESULTS

MEAS

SIGNAL

MAGNITUDE

FREQUENCY

EYE DIAG

[FREQ]

EYE

LENGTH

Dots

and

off

Lines

mode.

SYMBOL

DISPLAY

The

MAGNITUDE

measurement or reference signal as a function of time and symbol.

softkey displays the magnitude of the demodulated

1119.5063.12 2.4-49 E-5

Digital Modulation Methods FSE

The

FREQUENCY

frequency response of the signal, i.e., the frequency-demodulated signal. The frequency display is for instance suitable for m easuring the frequency

deviation by using the markers.

softkey displays the time- or symbol-dependent

EYE DIAG

[FREQ]

EYE

LENGTH

The

EYE DIAG [FREQ]

softkey displays the frequency-demodulated signal as a function of time. This signal is triggered by the symbol clock at the points of decision. on the time axis) is determined by

The display range of the eye diagram (number of st ates

EYE LENGTH

The individual traces of the eye diagram are s uperimposed on each other until the number of symbols spec ified with

RESULT LENGTH

is attained. The successive trac es are the continuation of the trac e written last, i.e. the total trace is displayed in a folded form. T o obtain a com plete eye diagram, all the states of a signal have to be traced at least once. T he number of eyes corresponds to the number of modulation states less 1. The eye aperture is a measure for differentiating between two decision levels. A small eye apertures indicate a high, large eye apertures a sm all bit error rate.

The

EYE LENGTH

softkey determines the display width of the eye diagram in

symbols. The number of symbols is entered in the field. At least one symbol length or two states are required for a complete eye. Two

to five symbols are recomm ended however to detect the err ors particular ly at the zero crossings. The number of symbols is limited by In the case of

EYE LENGTH

RESULT LENGTH

, however, the signal

versus time is displayed, the eyes are no longer visible.

SYMBOL

DISPLAY

SYMBOL DISPLAY

displayed trace. The desired form of highlighting can be selected from the

softkey marks the symbol decision points in the

The table. Points of decision can be marked by vertical lines or by dots..

SYMBOL DISP LAY

off Dots Lines

With

off

selected, the points of decision are not highlighted. When

selected, points are drawn on the trace and with

Lines

selected (except for

Dots

are

vector and constellation diagrams), vertical lines are drawn between the X axis and the trace.

1066.4313.02 2.4-50 E-5

FSE Digital Modulation Methods

2.4.3.4.3 Measurement of Modulation Errors

The FSE evaluates the modulation errors by comparing the measurement signal with the internally generated ideal reference signal. The output formats diff er depending on whether FSK demodulation is selected or not. The different output formats of the er ror are selec ted by means of the softkey.

Non-FSK demodulation:

The modulation error of the measurement signal can be displayed separately, i.e. according to magnitude and phase, as I and Q error, error vector magnitude or, in polar diagrams, as vector or constellation diagram.

The magnitude and phase error are determined according to the following equations:

Error signal magnitude = Error signal phase =

arctan

+ - IQ

− , where

arctan

+ and

ref2ref

ref

the real and imaginary part of the error signal are given as follows

ERROR SIGNAL

Error signal real part = I - I Error signal imag part = Q - Q

ref

and

ref

The magnitude of the error vector (error vector magnitude) is

EVM =

(I I ) ( Q Q )

−+−

ref

I, Q = measured I/Q component

ref

= I/Q components ideally calculated from the bit sequence.

ref

The following vector diagram indicates the different types of errors resulting from the measurement signal and the reference signal:

Quadrature component

Ideal

ref

symbol point

Reference vector

Amplitude error

Error vector

Measured symbol point

Phase error

Phase of error vector

ref

Error vector shifted to its origin (polar diagram of error vector)

Inphase component

Fig. 2.4-15 Graphic display of modulation errors by means of a point of decision

1119.5063.12 2.4-51 E-5

Digital Modulation Methods FSE

Submenu:

ERROR

SIGNAL

CONFIGURATION MODE - VECTOR ANALYZER - MEAS RESULT

ERROR

SIGNAL

MAGNITUDE

The

ERROR SIGNAL

softkey opens the submenu for selecting

the type of error to be displayed. The following types of error representation are available

• amplitude error (MAGNITUDE)

PHASE

FREQUENCY

• phase error (PHASE)

• frequency error (FREQUENCY)

• error if the real part (REAL/IMAG PART) and

REAL/IMAG

PART

• error of the imaginary part (REAL/IMAG PART)

• magnitude error (ERROR VECTOR MAGNITUDE)

For error representation the FSE compares all the points of the measurement and reference signal and displays them in the

ERROR VECT

MAGNITUDE

POLAR [IQ]

VECTOR

POLAR [IQ]

CONSTELL

SYMBOL

DISPLAY

error diagram (except for number of measurement results depends on the number of points per symbol. If only the errors are to be evaluated at the points of decision, the number of points per symbol has to be set to one.

To maintain the correct error for discontinuous transmission, e.g. for TDMA methods , make sure that only valid symbols are displayed. The result length and the trigger condition have to be set appropriately.

POLAR [IQ] CONSTELL

). Thus, the

MAGNITUDE

PHASE

FREQUENCY

REAL/IMAG

PART

The

MAGNITUDE

softkey starts the point by point comparison of the magnitude of the meas urement signal with the m agnitude of the ideal signal. The difference of the two magnitudes is displayed..

The

PHASE

softkey starts the point by point comparison of the phase of the measurement s ignal with the phase of the ideal signal. T he differenc e of the two phases is displayed as phase error.

The

FREQUENCY

softkey displays the frequency error. The frequency response of the measurement signal is compared with that of the ideal reference signal and the difference between the two responses is displayed as a function of time and symbol. The softkey is only available for MSK demodulation .

The

REAL/IMAG PART

softkey displays the error of the real and imaginary part in separate diagrams. T o this effect, the measurement diagr am is split up. The real part is displayed in the top half and the imaginary part in the bottom half. The X axis (time or symbols) is identical for the two diagrams.

1066.4313.02 2.4-52 E-5

FSE Digital Modulation Methods

ERROR VECT

MAGNITUDE

POLAR [IQ]

VECTOR

POLAR [IQ]

CONSTELL

FSK demodulation: Submenu:

ERROR

SIGNAL

CONFIGURATION MODE - VECTOR ANALYZER - MEAS RESULT

The

ERROR VECT MAGNITUDE

softkey displays the magnitude of the error

vector versus time or symbols.

The

POLAR [IQ] VECTOR

and

POLAR [IQ] CONSTELL

softkeys display the error vector in the polar diagram. The error vector diagram and the error constellation diagram.

With these form s of representation, the points of decis ion are all shifted bac k to the origin and are laid on top of each other. The errors at the points of decision can thus be seen at a glance.

ERROR

SIGNAL

MAGNITUDE

The

ERROR SIGNAL

softkey opens the submenu for selecting

the type of error to be displayed. The following quantities can be displayed:

• Magnitude error (MAGNITUDE)

• Frequency error (FREQUENCY)

FREQUENCY

MAGNITUDE

measurement signal with the magnitude of the ideal signal.

softkey starts the point by point comparison of the

The The difference of the two magnitudes is displayed.

The

FREQUENCY

The frequency response of the measurement signal is compared with that of

softkey displays the frequency error.

the ideal reference signal and the differ ence between the two responses is displayed as a function of time and symbol.

1119.5063.12 2.4-53 E-5

Digital Modulation Methods FSE

2.4.3.4.4 Symbol Table and Table of Modulation Errors

The symbol table and the table with modulation errors are indicated in the same display. In this case, the two tables are assigned to a trace. Similar to the trace display, the corresponding trace can be frozen

VIEW

) or faded out (

( The range for the error calculation can be limited by means of the time lines (TIME LINES 1/2;

If only one window is displayed, the symbol table is assigned to trace 1 and the error table to trace 2.

menu,

BLANK

SEARCH LIM ON/OFF

MARKER

menu).

Submenu:

SYMB TABLE

/ERRORS

CONFIGURATION MODE - VECTOR ANALYZER - MEAS RESULT

The

SYMB TABLE / ERRORS

and a table of modulation errors of the measured signal. The symbol table shows the demodulated bits of the signal. The number of

bits is defined under related to the traces (in split screen mode) by means of the marker coupling. The mark er on the trace and the associated symbol are m arked at the same time. The indicated modulation error s differ depending on whether FSK signals are demodulated or one of the other digital demodulators is active.

The following parameters are indicated as sum errors of the modulation (except with FSK demodulation):

• Frequency error

• Magnitude error

• Phase error

• Error vector magnitude

• I/Q offset

• I/Q imbalance and

• Amplitude droop

RESULT LENGTH

softkey displays a table of demodulated bits

in the same menu. Bits can be

• Rho factor. The FSE evaluates these errors within the result length

by the vertical lines within the result length. With FSK demodulation, the following parameters are indicated as sum

errors of the modulation:

• Frequency error

• Magnitude error

• FSK deviation

• FSK deviation error

The entered reference deviation is indicated in addition (

DEVIATION

1066.4313.02 2.4-54 E-5

or in a range limited

FSK REF

FSE Digital Modulation Methods

Non-FSK demodulations:

Fig. 2.4-16 Symbol table and table of sum errors (not FSK demodulation) Description of errors as follows (not FSK signals): Magnitude error: The magnitude error is the amplitude difference of the I/Q components of

measurement signal and reference signal at the points of decision. For MSK modulations, all the points are consider ed in the calculation. It is a measure for the quality of the amplitude component of the modulated signal.

Phase error: The phase error is the phase difference of the I/Q components of measurement

signal and reference signal at the points of decision. For MSK modulations, all the points are considered in the calculation.

Vector error: The error vector magnitude is the magnitude of the error vector which links the

measured I and Q value in the complex plane to the ideal I and Q value at the points of decision. The error is calculated according to the following equation:

Error vector magnitude (EVM) =

= error of the inphase signal and

err

= error of the quadrature signal

err

+ , where

err

Frequency error : The frequenc y error is the deviation of the FSE c enter frequency from the measured

carrier frequency. It is derived from the frequency shift to be effected for synchronization to the carrier. The reference error of the FSE is also part of the frequency error.

Amplitude droop:The amplitude droop indicates the amplitude variation of the signal between the two

symbols at the points of decision in dB. This parameter is ver y important for TDMA signals and is a measure for the quality of pulse modulation.

1119.5063.12 2.4-55 E-5

Digital Modulation Methods FSE

I/Q offset: The I/Q offset is a m easure for the LO feedthrough with analog I/Q modulators. It

can be seen through a shift of the zero point in the constellation diagram. Without LO feedthrough (LO 100 % suppressed), the I/Q offset is zero. It is measured at the points of decision.

I/Q offset

Fig. 2.4-17 Constellation diagram with I/Q offset

Amplitude and vector errors ar e given in %, phase errors in degrees ( deg) or radian (rad). Prior to calculation, the measurement result is normalized in the vector or constellation diagram to a circle around the center of the group mid-points, the radius corresponding to the mean distanc e of all group mid- points to the center. This circle is defined as a unit circle with the radius 1 (see

MODULATION PARAMETER menu

)

NORMALIZE

Then, the errors at the points of decision are determined and the rms of the individual error values is calculated. Sinc e the constellation diagram is norm alized, the result is the rms value of the error in %.

function in the

I/Q imbalance: The I/Q imbalance is a measure for the symmetry of the I/Q modulator to be

measured. The I/Q gain error is the result of unequal gain factors in the I and Q path of the transmitter. The I/Q imbalance is calculated from the square root of the quotient of the vector magnitude for the wanted and interfering signals averaged over all points of decision:

[]

Interference vector

Signal vector

I / Q imbalance = 100*

Ideal constellat ion poin t

Offset-cor rect ed center

Interferencevector

∑

Signal vector

Fig. 2.4-18 Constellation diagram with I/Q imbalance

1066.4313.02 2.4-56 E-5

FSE Digital Modulation Methods

Rho factor: Sim ilar to the error vector magnitude, the Rho f actor is a m easure for the quality of

digital modulation. It is determined by measurement of the normalized correlated power between the measured signal and reference signal (IS95-CDMA to US standard IS-98) and is designated as waveform quality factor. The Rho factor can assume a maximum value of 1.0 (measured signal and reference signal are a 100% identical).

FSK demodulation:

Fig. 2.4-19 Symbol table and table of sum errors (FSK demodulation)

The various errors and measured values have the following meaning (FSK signals): FSK deviation: The FSK deviation is determined by the square difference between m easure-

ment and reference signal being m inimized. The reference signal is based is

formed on the basis of the known demodulated bits and modulation

parameters. The frequency offset is determined separately and indicated

under Freq Error. The frequency error is not considered in the indicated FSK

deviation. FSK deviation error: The FSK deviation error is the deviation difference between the measured

signal and the reference signal, measured as an rms and peak value over all

symbols. Frequency errors (frequency offset) are part of the indicated FSK

deviation error.

Normalize ON The entered FSK reference deviation is used for sc aling of

the reference signal.

Normalize OFF The reference signal is automatically derived from the

measurement signal on the basis of the known demodulated symbols and modulation parameters so as to ensure maximum agreement between measurement and reference signal.

Magnitude error: With FSK, the magnitude error is the deviation of the individual amplitudes of

the AM envelope from the mean (rms) car rier am plitude, meas ured as an rm s

value over all symbols displayed and as a peak value normalized to the rms

amplitude in %. Frequency error: The frequency error is the deviation of the FSE center frequency from the

measured carrier frequency. It is derived from the frequency shift to be

effected for synchronization to the carrier. The ref erence error of the FSE is

also part of the frequency error.

1119.5063.12 2.4-57 E-5

Digital Modulation Methods FSE

2.4.3.5 Selecting Memory Size, Demodulation Length and Display Range

The size of the capture buffer c ontaining the stored samples, the frame length to be demodulated and displayed and the number of points per symbol can be set to allow an adaptation to the meas urement or to optimize the measurement speed. At the beginning of a measurement, the FSE stores the samples into the c apture buffer which can be selected between 1 and 16-k symbols. It then tries to find the suitable frame length for further processing according to the trigger c ondition ( for error calculation is defined with synchronization sequence triggering (

MEMORY SIZE

RESULT LENGTH

FIND SYNC

FRAME

LENGTH

RESULT LENGTH

FIND BURST

). The fram e length to be displayed or used

. It can be positioned within the frame length by

Trigger: Free Run Video Extern

Find Burst Find Sync

Finally, the number of points per symbol can be set. This number defines the maximum number of symbols that can be processed in the

Submenu

CONFIGURATION MODE - VECTOR ANALYZER - MEAS RESULT

MEMORY

SIZE

The saved in the capture buffer per measurement is determined. Within the memory size

FIND BURST

for (

MEMORY SIZE

163 84 PO INT S 8192 PO INT S 4096 PO INT S 2048 PO INT S 1024 PO INT S

Only the symbols entered under

FRAME LENGTH.

MEMORY SI Z E

a burst, e.g. in the case of a TDMA signal, can be sear ched

function).

softkey calls up a table in which the num ber of sam p les

FRAME LENGTH

are used for

demodulation. For symbol rates > 1 MHz the data are stored in the m emory without prior

filtering and reduction. The maximum memory size is therefore reduced to 4096 points.

1066.4313.02 2.4-58 E-5

FSE Digital Modulation Methods

FRAME

LENGTH

The

FRAME LENGTH

softkey calls up a table in which the number of

symbols to be demodulated or evaluated is defined.

FRAME

LENGTH

1600 SYMBOLS 1500 SYMBOLS 1400 SYMBOLS 1300 SYMBOLS 1200 SYMBOLS 1100 SYMBOLS 1000 SYMBOLS 900 SYMBOLS 800 SYMBOLS 700 SYMBOLS 600 SYMBOLS 500 SYMBOLS 400 SYMBOLS 300 SYMBOLS 200 SYMBOLS 100 SYMBOLS

With up to 4 points per symbol a maximum of 1600 symbols can be demodulated per measur ement and their modulation parameters measured. With 8 points per symbol up to 800 symbols, and with 16 points per symbol up to 400 symbols can be handled.

With symbol rates >1 MHz to ≤1.28 MHz a maxim um of 600 symbols can be handled. This is due to the fact that the data are stored in the memory without prior reduction. The subsequent reduc tion limits the FRAME LENGT H in the specified frequency range.

The frame length markedly influences the time required for evaluating a measurement signal. It is therefore recommended to choose the frame length as short as possible. 400 symbols, f or ex am ple, ar e suf f icient f or determ ining the phase error of a GSM burst as only 147 symbols are to be evaluated. The FSE automatically searches for the correct tim e domain by trigger functions

FIND BURST

and

FIND SYNC

The choice of the frame length influences the m aximum number of points per symbol. With up to 400 s ymbols a maximum of 16 points, with >400 up to 800 symbols a maximum of 8 points and with >800 symbols a maximum of 4 points per symbol is possible.

With symbol rates >1MHz to ≤1.20 MHz, the maximum number of symbols is 500!

1119.5063.12 2.4-59 E-5

Digital Modulation Methods FSE

RESULT LENGTH

POINTS PER

SYMBOL

The

RESULT LENGTH

softkey opens a window for defining the number of

symbols for display on the screen. The maximum result length is identical to the frame length. With the

FIND SYNC

function activated (synchronization to bit sequences in the signal), the maximum result length can be reduced (or the frame length increased).

The

POINTS PER SYMBOL

softkey opens a window for entering the number

of points per symbol. 1, 2, 4, 8 and 16 points per symbol can be selected. With one point per

symbol, each point in the display corresponds to a symbol sampled at the time of decision. With n points per symbol, each n-th value is a point of decision. With 1 and 2 points per symbol, the FSE demodulates with 4 points per symbol for reasons of accuracy. Only one or two samples are output, however. For up to 4 points per symbol, a frame length of max.

1600 symbols is possible, with 8 points per symbol a frame length of m ax. 800 symbols and with 16 points per symbol of max. 400 symbols.

In the case of MSK demodulation, the number of points per symbol influences the result of the error measurement as all the points are considered in the calculation. With all other demodulators, only the values measured at the points of decision are taken into account. For GSM (DCS1800 and PCS1900) less than 4 points per symbol should not be used.

The number of points per symbol largely influences the m easurement s peed attained during the evaluation of the signal. If high measurem ent rates are to be attained for automatic tests, for example, a low number of points per symbol is recommended.

1066.4313.02 2.4-60 E-5

FSE Frequency Settings /Vector Signal Analysis

2.4.4 Frequency Settings - FREQUENCY Key Group

In vector signal analysis, FSIQ is always set to a fixed frequency. The RF signal is analyzed by converting the signal into the complex baseband.

The frequency of FSIQ is set in the same way as in the spectrum analysis mode, i.e. with the key in the

FREQUENCY CENTER

FREQUENCY

CENTE R SPAN

FREQUENCY

key group.

CENTER

FREQUENCY

The

CENTER

key calls up the entry window for the

center frequency . For the demodulation of digitally modulated signals, the

FSIQ frequency has to be accurately set to the frequency

START STOP

(carrier) of the signal to be measured so that synchronization to the carrier is possible. The required setting accuracy depends on the symbol rate and must not exceed 2% of the symbol rate.

FREQUENCY

OFFSET

CENTER

FREQUENCY

OFFSET

The

FREQUENCY OFFSET

softkey activates the input of a frequency offset which can be added to the frequency-axis labeling. The displayed frequency is shifted by the frequency offset. The range of values for the offset is -100 GHz to +100 GHz.

1066.4313.02 2.4-61 E-5

Frequency Settings - Vector Analyzer FSIQ

2.4.5 Setting the Frequency Span - START, STOP, and SPAN Key

The

SPAN, START

digitally modulated signals since FSIQ is always set to a fixed frequency and the measurement results are displayed in the time domain. The analysis bandwidth by which the demodulation is perform ed is predefined by the symbol rate and the number of sampling points.

and

STOP

keys are not assigned in vector signal analysis for the dem odulation of

1066.4313.02 2.4-62 E-5

FSE Level Display/RF Input

2.4.6 Setting the Level Display and Configuring the RF Input

2.4.6.1 Setting the Reference Level

With spectrum analysis (ANALYZER mode) of the FSIQ, the level applied to the RF input is always indicated on the display so that one can see the relationship between the setting of the reference level and the measurement results on the display.

With vector s ignal analysis, this only applies to operating mode

BUFFER

demodulated signal is displayed this relationship is not obvious. That is why a strict distinction has to be made between setting the reference value which is an important reference point for the measuredvalue display and the reference level relating to the RF input.

To obtain a maximum dynamic range it is impor tant for the signal level at the A/D converter to be close to the maximum level of the converter. The maximum level of the converter corresponds to the reference level ( attains the reference level in the spectrum analysis mode is ideal for the vector analyzer mode. An important factor is the sum level within the IF bandwidth (= analysis mode) of the analyzer.

The reference level can be manually set by checking the signal level in the spectrum analysis mode against the set frequency (at the same IF bandwidth!) and by operating the vector analyzer with the same setting. The FSET can perform this in vector signal analysis but also by a single automatic setting of the reference level.

Certain settings of the spectrum analysis mode such as center frequency, reference level and attenuation are taken over by the vector signal analysis. Parameters that are not af fected are span (in vector signal analysis, the frequency span has a different meaning: it corresponds to the analysis bandwidth and is thus independent in the two operating modes), resolution bandwidth, ref. level offset as well as trace and trigger settings

The reference value ( measured value. Apart from

BUFFER

determined.

In operating mode

REF LEVEL

DIGITAL DEMODULATION

) in the spectrum analysis mode. This means that a signal whose amplitude

REF VALUE

) of the vector signal analysis is the reference point f or scaling the

DIGITAL DEMODULATION-RESULT DISPLAY-MAGNITUDE CAP

it is decoupled from the setting of the reference level, i.e. a direct relationship cannot be

DIGITAL DEMODULATION, MAG CAP

with activated demodulation , e.g. when the

ANALOG BANDWIDTH

in vector signal

With the The

such as auto scaling ( (X/Y_REF VALUE) and the relative position of the reference value on the diagram (

POSITION

1066.4313.02 2.4-63 E-5

REF

RANGE

key, the reference level can be set like in the spectrum analysis mode.

key calls up a menu com prising all the settings required for scaling the measured value

AUTO SCALE

), scaling (Y per Div), reference values in the X and Y direction

REF VALUE

Level Display/RF Input FSE

LEVEL REF

LEVEL

REF

RA E

REF LEVEL

RF LEVEL

OFFSET

ATTEN STEP 1dB 10dB

RF ATTEN

MANUAL

ATTEN AUTO

NORMAL

ATTEN AUTO

LOW NOISE

ATTEN AUTO

LOW DIST

MIXER LEVEL

The REF key calls up the menu for setting the reference level and at the same time activates the level entry field.

Operation and softkey functions identical to analyzer mode:

ATTEN STEP 1dB/10dB RF ATTEN MANUAL ATTEN AUTO NORMAL ATTEN AUTO LOW NOISE ATTEN AUTO LOW DIST MIXER LEVEL

Softkey

ATTEN STEP 1dB/10dB

is only available when the FSIQ is equiped with option FSE-B13, 1dB attenuator

REF LEVEL

OFFSET

The

REF LEVEL

softkey activates entry of the manual gain of the FSIQ. For a maximum dynamic range, it has to be ensured that the A/D converter is driven to its full range but not overdriven.

In the vector analyzer mode, this is indicated by the messages (overload) and

UNLD

(underrange) which inform on the dynamic range

IF OVLD

when measured data are read in. When

IF OVLD

is displayed, the instrument or the A/D converter is overdriven during data read-in and entered data are invalid. With

UNLD

displayed, the A/D converter is not sufficiently driven during data read-in (level <-6 dB of full range). Indicated values may have a reduced dynamic range, i.e. have a greater error.

For a correct level setting in the case of

IF OVLD

, reduce the REF LEVEL (continuous sweep mode) in sufficiently small steps (e.g. 2 dB) until the message disappears.

UNLD

Proceed analogously for increasing the REF LEVEL when

is displayed until the message disappears. The maximum dynamic range is attained approx. 1 dB below the

OVLD

level. The reference level can also be set to the test signal in the spectrum

analysis mode at the same IF bandwidth as in the vector signal analysis mode (with

COUPLED: ANALOG BW AUTO

also 10 kHz) and vector signal

analysis can then be selected again. The

REF LEVEL OFFSET

softkey activates the entry of a level offset. It is added to the measured level, irrespective of the unit used. The s caling of the Y axis is changed accordingly. This function is used to take into account the effect of an external attenuator on the displayed values. The setting range is ± 200 dB in 0.1 dB steps.

1066.4313.02 2.4-64 E-5

FSE Level Display/RF Input

2.4.6.2 Setting the Display Range and Scaling - RANGE Key

The menu for setting the display range is different from that of the spectrum analysis mode.

LEVEL RANGE

LEVEL

REF

RANGE

Y PER DIV

LEVEL RANGE

Y PER DIV

REF VALUE

Y AXIS

REF VALUE

X AXIS

REF VA LUE

POSITION

SCALE

UNIT

The

Y PER DIV

current unit.

The

RANGE

key calls up a menu comprising all the important display parameters such as reference value, scaling etc.

softkey calls for the entry of the vertical scaling in the

REF VALUE

Y AXIS

REF VALUE

X AXIS

For vector or constellation diagrams, the corres ponding X sc aling is linked with Y scaling:

X PER DIV =5/4 *(Y PER DIV) Reason: The diagram has 400 x 500 points. In case of a free X scaling

circles would be reproduced as ellipses.

The

REF VALUE Y AXIS

and

REF VALUE X AXIS

softkeys call for the entry

of the reference value for the Y or X axis of the m easurement diagram. The

REF VALUE X AXIS

softkey is only displayed if a polar diagram has been

selected for the trace. The reference value is entered in the corresponding unit of the diagram

UNIT

(See

1066.4313.02 2.4-65 E-5

Level Display/RF Input FSE

Example 1: Constellation diagram: y reference value: +1.20; x reference value: - 0,35

(reference position: 50%)

Fig. 2.4-17 Representation of the reference values in the constellation diagram

Example 2: Display of I and Q signals: Y reference value: -0.2 REF position: 50%

Fig. 2.4-18 Display of I and Q signals

1066.4313.02 2.4-66 E-5

FSE Level Display/RF Input

REF VALUE

POSITION

Submenu:

SCALE

UNIT

The positions diverging from the basic setting.

REF VALUE POSITION

lies at 100%, i.e. the maxim um displayable Y value is also the ref erence value. It is best to use this setting for displaying the magnitude which is then the basic setting.

When, for ex ample, the timing of I/Q signals or the phas e s pectr um is displayed it might be desirable to set the refer ence value to the center. T he basic setting is thus 50% (also for polar diagrams).

LEVEL RANGE

REF VALUE POSITION

defines the position of the reference value. It nor mally

SCALE

UNIT

Y UNIT

LOG[dB]

Y UNIT

LINEAR

UNIT DEG

UNIT RAD

Y UNIT dBm

Y UNIT VOLT

Y UNIT WATT

The

SCALE UNIT

the unit of the Y axis and the X axis are set. The units offered depend on the setting of

DISPLAY

The logarithmic unit dB ( linear units ( axis.

ERROR

units:

Y UNIT LOG [dB Y UNIT LINEAR

Errors of Phase errors are displayed in DEG or RAD, frequency

errors in Hz. Units which are not allowed in the current operating

mode are disabled.

softkey opens a window for setting the reference

softkey calls up a submenu in which

RESULT

and

MEAS RESULT

Y UNIT LINEAR

and

MAGNITUDE

Y UNIT [dB]

) or dimensionless

) are permissible for the Y

are displayed in the following

]: dB

: %.

REAL/IMAG PART

are always displayed in %.

X UNIT

TIME

X UNIT SYMB OL

In polar diagrams, the units for the X -axis and Y-axis are equal. The softkeys

X UNIT...

The time representation, the units time ( symbols (

X UNIT SYMBOLS

are suppressed.

X UNIT TIME

) can be used for the

) or

X-axis. The sof tkey for the X-axis unit are only shown in time representation.

If a marker is active, the m arker values are read out in the current scale units.

Only for MEAS RESULT: MAGNITUDE CAP BUFFER:

Possible display units:

dBm , Volt

and

Watt.

YUNIT LOG [dB], YUNIT LINEAR,

1066.4313.02 2.4-67 E-5

Level Display/RF Input FSE

Table 2.4-3 Allocation table of selectable units or, in c ase of error display, of the displayed units in

operating mode

MEAS RESULT

DIGITAL DEMODULATION

depending on

RESULT DISPLAY

and

RESULT

DISPLAY

-------------------

MEAS RESULT

MEAS SIGNAL

REFERENCE SIGNAL

ERROR SIGNAL VECTOR

ERROR

MAGNITUDE

CAP

BUFFER

Y_UNIT LINEAR Y-UNIT LOG[dB] dBm VOLT WATT

-- like

-- [%]

MAGNI-

Y_UNIT LINEAR

Y-UNIT LOG[dB]

MEAS SIGNAL

[dB]

TUDE

PHASE FREQUENCY

DEG/RAD Hz Y_UNIT

like MEAS SIGNAL

PHASE DEG/RAD

DEG/ RAD

[with FSK and

MSK only]

like MEAS SIGNAL

Hz -- - - -

-- [%] - [%] [%]

REAL/

IMAG

PART

LINEAR

like MEAS SIGNAL

EYE

DIAG

Y_UNIT LINEAR

like MEAS SIGNAL

2.4.6.3 Configuration of RF Input in Vector Signal Analysis

This section is identical to that of the spectrum analysis mode.

POLAR

[IQ]

VECTOR

Y_UNIT LINEAR

like MEAS SIGNAL

POLAR

[IQ]

CONSTELL

Y_UNIT LINEAR

like MEAS SIGNAL

INPU T

INPUT

RF ATTEN MANUAL

ATTEN AUTO

NORMAL

ATTEN AUTO

LOW NOISE

ATTEN AUTO LOW DIST

MIXER LEVEL

ATTEN STEP 1 dB 10dB

INPUT

SELECT

Note: The operating mode recommended for the vector

analyzer input is ATTEN AUTO NORMAL. If ATTEN AUTO LOW NOISE is set (or for MIXER LEVEL

≥

–30 dB), the higher signal modulation occuring within the IF-bandwidth causes a nonlinear behavior in the IF branch. This leads to increased measurement er rors, in particular for modulation types with a nonconstant level (e.g. PSK).

1066.4313.02 2.4-68 E-5

FSE Vector Analyzer - Main Marker

2.4.7 MARKER Key Group

In the vector analyzer mode markers m ay be used for highlighting points in a trace and for reading out measured values. For detailed information see section ’Marker Function’ in chapter ’Analyzer Mode’. In the vector analyzer mode marker softkey functions depend on the selected measurement.

2.4.7.1 Main Marker -

NORMAL

Key

The main markers and their functions are selected with the

MARKER NORMAL

MARKER

NORMAL SEARCH

D TA

MKR

MARKER NORMAL

MARKER 1

MARKER 2

The

NORMAL

standard marker functions. Activated marker functions are indicated by a dark

background of the softkeys. If no marker is activated when the activated as a reference and set to the maximum value in the curve. (automatic switch-on of peak search

POLAR MKR

R/I MA/PH

POLAR MKR DEG RAD

COUPLED MARKERS

function provided at least one trace is active; not with polar diagram). In all other cases the reference marker is activated but no automatic peak search is performed.

In the marker field the marker position (time), the measured value or values (in the case of a complex display) and the trace relevant for the marker (here [T1]) are displayed.

Example: Marker display in the digital demodulation and I/Q display mode:

MARKER INFO

ALL MARKER OFF

Marker 1 [T1/3] 22.3 µs Real 0.998 Imag -0.124

When the symbol table is displayed (softkey

TABLE/ERRORS

marker m oves from symbol to symbol in the table. T he position of the mark er is indicated by a dark back ground and its numerical value in inverse video.

NORMAL

key.

key calls up a menu comprising all

NORMAL

key is pressed, MARKER 1 is

in submenu

MEAS RESULT

SYMB

) the

In the marker f ield, the marker position and the decimal value of the symbol are displayed.

MARKER NORMAL

MARKER 1

MARKER 2

The

MARKER 1

and

MARKER 2

softkeys switch the respective m arker on or

off or define it as an entry marker (reference marker).

1066.4313.02 2.4-69 E-5

Main Marker - Vector Analyzer FSE

POLAR MKR

R/I MA/PH

POLAR MKR

DEG RAD

COUPLE D MARKER S

The

POLAR MARKER R/I / MA/PH

(

MA/PH

) or real and imaginary part (

softkey selects magnitude and phase

R/I

) for the numeric result display in the polar diagram. When measured values are indicated versus time this softkey is disabled.

The

POLAR MARKER DEG/RAD

radiant (

RAD

) for indication of the phase of the marker in the respective

softkey selects the unit degree (

DEG

) or

diagram.

The

COUPLED MARKER

different traces in the com bined display mode

softkey couples markers (and delta markers) of

REAL/IMAG PAR

. In this case the X position of corresponding markers is identical. This allows complex marker values to be dis played which correspond to the polar display.

Marker 1 6.75 SYM [T1/3] RE 0.895 IM 1.002 If several windows are displayed, the markers of all windows are coupled when the

COUPLED MARKERS

function is active.

1119.5063.12 2.4-70 E-5

FSE Vector Analyzer - Main Marker

ALL MARKER

OFF

MARKER

INFO

The

ALL MARKER OFF

softkey switches all m ark ers inc luding ref erenc e and

delta markers off and closes the marker entry window. In addition the

MARKER INFO

The

MARKER INFO

softkey is switched off.

softkey allows several mark ers to be displayed in the grid, in addition to the display of marker information in the m arker field of the diagram headline. In the top right-hand corner of the grid the two mar kers or delta mark ers are displayed with symbols ∇/∆, marker number (1, 2), position and measured value (may be complex). The number of symbols for spec ifying the marker position is limited in certain cases.

If there are not enough lines for displaying all active markers and delta markers, the markers are listed first and then the delta markers.

SPLIT SCREEN

In the

SCREEN A

and one for

display this list is divided into two lists, one for

SCREEN B

1066.4313.02 2.4-71 E-5

Delta Marker - Vector Analyzer FSE

2.4.7.2 Delta Marker - DELTA Key

MARKER DELTA

MARKER

NORMAL SEARCH

DELTA

MKR

DELTA

MARKER

DELTA 1

DELTA 2

DELTA MKR ABS REL

The

DELTA

key in the MARKER key group selects the

delta markers. Delta markers are always referenced to the active

reference mark er . When no m arker is active, switching on a delta marker automatically activates marker 1. Delta

markers are displayed as an unfilled symbol the delta marker is active for entry, a f illed symbol

. When

displayed.

DELTA

MARKER

DELTA 1

DELTA 2

DELTA MKR ABS REL

ALL DELTA OFF

ALL DELTA

OFF

The

DELTA 1

and

DELTA 2

softkeys switch on delta markers 1 and 2.

Operation of delta markers is identical to that of markers. When a delta marker is s witched on, all entries apply to the delta mark er. For changing the position of the main marker, the main m arker has to be reactivated. Displayed differences normally apply to the active reference marker.

In the delta marker field, the number of the delta marker, the time difference to the referenc e mark er and the differ ence of meas ured values between the active delta marker and reference marker are displayed.

The

DELTA ABS / REL

relative (

REL

) input of time of the delta marker.

Default setting is

The

ALL DELTA OFF

REL

softkey switches between absolute (

ABS

) and

(input relative to the reference marker)

softkey switches off all active delta markers and any

associated functions.

1119.5063.12 2.4-72 E-5

FSE Vector Analyzer - Search Menu

2.4.7.3 Search Functions (Marker Search menu) - SEARCH Key

The menus called up with

offer functions for a peak/min search and universal marker functions for overall evaluation of traces. The search functions can be used for markers and delta markers.

Important: With polar diagrams, peak/min. peak values refer to the vector length (with origin as

reference), in all other cases to the Y deflection. In this diagram , sum mar y markers cannot be switched on or are not displayed.

Functions in the

MARKER SEARCH

Switchover between the active marker and delta marker is possible with the

menu refer to the marker or delta marker active during entry.

ACTIVE MKR DELTA

softkey. If no marker is switched on when the

key is pressed, marker 1 is activated as reference

marker (by means of peak search). The search range can be limited by time lines (

TIME LINE 1/2

) switched on with

SEARCH LIM ON/OFF

The limitation of the search range is valid f or all the marker s earch functions including the SUMMARY MARKERS and for error calculation during

SYMB TABLE/ERRORS

The time lines are only visible for diagr ams vers us time, i.e. not f or polar diagram s and for diagr ams of

SYMB TABLE/ERRORS

. The limitation of the search range is valid for

SEARCH LIMITS ON

for all

diagrams irrespective of whether the time lines are visible or not.

MARKER SEARCH

MARKER

NORMAL SEARCH

DELTA

MKR

MARKER SEARCH

PEAK

MIN

SUMMARY

MARKER

MAX |PEAK|

+ PEAK

MAX |PEAK|

SUM MKR

SEARCH LIM ON

ACTIVE

MKR DELTA

OFF

SUMMARY

MARKER

OFF

SELECT

The search range can be lim ited by the time lines (TIME LINE 1/2) (softkey The limitation of the search range extends to all marker search functions including the

MARKER

as well as to error calculation during

SYMB TABLE/ERRORS

- PEAK

PEAK/2

RMS

MEAN

PEAK HOLD

ON OFF

AVERAGE

ON OFF

SWEEP COUNT

ALL SUM MKR OFF

SEARCH LIM ON/OFF)

SUMMARY

The time lines are only visible for diagrams versus time, ie not for polar diagrams and for diagrams representing

SYMB TABLE/ERRORS

. The limitation of the search range during

SEARCH LIM ON

extends to all types of representation, irrespective of whether the time lines are visible or not. The functions in the for entries. Softkey

MARKER SEARCH ACTIVE MKR DELTA

active delta marker. If no mark er is switched on bef ore

menu refer to the mark er or delta marker that is currently active

may be used to switch between the active mark er and the

is pressed, mar ker 1 will be activated

as reference marker (with peak search).

1066.4313.02 2.4-73 E-5

Search Men FSE

ACTIVE

MKR DELTA

SELECT MARKER

MAX |PEAK|

PEAK

The

ACTIVE MKR / DELTA

softkey switches over between active mark er

and active delta marker. With

DELTA

highlighted, subsequent search functions are carried out with

the active delta marker.

Note: Switchover between marker and delta marker entry is also

possible with the NORMAL and DELTA keys.

The

SELECT MARKER

softkey opens the table for selection of the mark er

or delta marker.

The

MAX |PEAK|

highest magnitude displayed (

softkey sets the active marker or delta marker to the

PEAK

MIN

) in the associated curve.

For instance, the function searches for the maximum phase error of a signal, which may be positive or negative.

The

PEAK

softkey sets the active marker or delta marker to the highest

value displayed in the associated measured curve.

MIN

SEARCH LIM ON OFF

The

MIN

softkey sets the reference marker to the lowest value in the

associated curve.

The

SEARCH LIMIT ON/OFF

switches between limited (ON) and unlim ited (OFF) search range. The search range can be limited by time lines (

TIME LINE1/2)

for peak-

and min-search functions as well as for the summary markers. If

SEARCH LIMIT

is ON, a search for the corresponding signals is only

performed between the two lines. If only one line is switched on,

upper limit is the stop frequency),

TIME LINE 1

TIME LINE 2

is valid as lower limit (the

defines the upper limit

value. If no line is active, lines 1 and 2 are switched on automatically and

positioned to 20 % and 80 % of the grid. If the function is switched off, the lines continue to be switched on. Time lines are not visible for polar diagrams and for Symb Table/Errors.

The limitation of the search range, however, remains effective. Default value is

SEARCH LIMIT OFF.

1066.4313.02 2.4-74 E-5

Rohde & Schwarz FSE-B7 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

Index

FSE-B7 Preparation for Use

FSE-B7 Menu Overview

2.2.1 SYSTEM Key Group

2.2.3 HARDCOPY Key Group

2.2.4 FREQUENCY Key Group

2.2.5 LEVEL Key Group, INPUT Key

2.2.6 MARKER Key Group

2.2.7 LINES Key Group

2.2.8 TRACE Key Group

2.2.9 SWEEP Key Group

2.2.10 MEMORY Key Group

2.2.11 USER Key Group

FSE-B7 Vector Analyzer Mode

2.4.1 Selecting the Operating Mode

Analog demodulation methods FSE-B7

2.4.2.1 Selecting the Modulation Parameters

2.4.2.2 Selecting the Audio Signal

2.4.2.3 Triggering with Analog Demodulation - Softkey TRIGGER or Hardkey TRIGGER

FSE Digital Modulation Methods

2.4.3.1 Diagram for signal processing

2.4.3.2 Symbol Mapping

2.4.3.3 Selecting the Digital Demodulators

2.4.3.4 Standard Settings

2.4.3.5 Selecting Modulation Parameters for Digital Demodulation

2.4.3.4 Selecting Measurement Results for Digital Demodulation

2.4.3.5 Selecting Memory Size, Demodulation Length and Display Range

2.4.4 Frequency Settings - FREQUENCY Key Group

2.4.5 Setting the Frequency Span - START, STOP, and SPAN Key

2.4.6 Setting the Level Display and Configuring the RF Input

2.4.6.1 Setting the Reference Level

2.4.6.2 Setting the Display Range and Scaling - RANGE Key

2.4.7 MARKER Key Group

2.4.7.2 Delta Marker - DELTA Key

2.4.7.3 Search Functions (Marker Search menu) - SEARCH Key