12 | Keysight | E1968A GSM/GPRS/EGPRS Test Application - Technical Overview

8PSK/16QAM multislot-tolerant modulation

accuracy measurement

All specifications for the 8PSK/16QAM multislot-tolerant modulation accu-

racy measurement are valid for the frequency ranges 700 to 800 MHz, 810

to 960 MHz, and 1.7 to 1.99 GHz.

Types of signals

measured

Normal 8PSK/16QAM bursts

Multislot input signal

conditions

≤ 30 dB difference in power level between

adjacent timeslots

Multislot signal

measurement capability

Measurement of one user-specified timeslot

transmitted as a single timeslot or four adjacent

timeslots

Frequency capture range Signal must be within ± 200 Hz of test set’s

expected frequency for warranted performance

Minimum input level

Signal at test set’s RF IN/OUT must have

8PSK/16QAM burst power ≥ –15 dBm for

warranted performance

Residual rms EVM

< 1 percent for 8PSK

< 1 percent for 8PSK difference ≤ 30 dB

rms EVM measurement

accuracy

< 0.5 or > –1.0 for 8PSK

< 1.5 or > 2.0 for 16QAM for measured average

rms EVM between 1 and 10 percent

Sample EVM

measurement accuracy

< ± 4 percent

Frequency error

measurement accuracy

< ± 10 Hz plus timebase accuracy

Origin offset suppression

measurement accuracy

for 8PSK

< ± 1.5 dB for measured origin offset

suppression between 25 and 40 dB

Trigger sources

RF rise, protocol, immediate, auto, external

Trigger delay

Settable between ± 2.31 ms

Burst synchronization

Midamble

Displayed graphical

results

EVM versus symbol, demodulated symbols

in octal and binary, magnitude error versus

symbol, phase error versus symbol, sample

EVM histogram with plots of measured sample

EVM PDF, expected sample EVM PDF, 95th

percentile EVM, and probability with settable

markers and variable axes

Multi-measurement

capabilities

1 to 999 bursts; maximum, minimum, and

average results

Concurrency capabilities 8PSK multislot-tolerant modulation accuracy

measurements can be made concurrently with

all other measurements

Supplemental characteristics

Measurement resolution 0.01 percent

Frequency error

measurement resolution

0.01 Hz

Origin offset suppression

measurement resolution

0.01 dB

Amplitude droop

measurement resolution

0.01 dB

Magnitude error

measurement resolution

0.01 percent

Phase error

measurement resolution

0.01 degree

IQ imbalance

measurement resolution

0.01 dB

Probability measurement

resolution

0.01 percent

GSM/GPRS/EGPRS multislot transmit power

measurement

The following specifications are valid when the burst capture range is set

to Single:

Types of signals

measured

Normal GMSK bursts sent as GSM or GPRS signals,

CW, RACH bursts for a single uplink timeslot only

Multislot input signal

conditions

≤ 30 dB difference in power level between

adjacent timeslots

Multislot signal

measurement

capability

Measurement of one user-specified timeslot

transmitted as a single timeslot or two adjacent

timeslots

Frequency capture

range

Signal must be within ± 100 kHz of test set’s ex-

pected frequency for warranted performance

Minimum input level Signal at test set’s RF IN/OUT must have transmit

power ≥ –25 dBm for warranted performance

Measurement accuracy at RF IN/OUT port between

+20 and +55 °C

Accuracy (dBm)

Frequency (MHz)

Timeslot

< ± 0.27

< ± 0.29

810 to 960

450 to 496

700 to 800

1700 to 1990

Single slot and multis-

lot at the same level

< ± 0.52

< ± 0.54

810 to 960

450 to 496

700 to 800

1700 to 1990

Multislot at different

levels

Measurement accuracy when RF OUT ONLY port is selected for

signal generation (in addition to measurement accuracy at

RF IN/OUT port):

Accuracy (dBm)

Frequency (MHz)

< ± 0.27

< ± 0.29

450 to 496

700 to 800

810 to 960

< ± 0.52

< ± 0.54

1700 to 1990

VSWR at RF IN/OUT

< 1.14 : 1 for 450 to 496 MHz and 700 to

960 MHz, < 1.2 : 1 for 1.7 to 1.99 GHz

Trigger sources

RF rise, protocol, immediate, auto, external

Trigger delay

Settable between ± 2.31 ms

Figure 2. EGPRS modulation accuracy measurement includes a

graphical sample EVM histogram to observe your device’s

statistical EGPRS performance.