Rohde & Schwarz CMU-K20, Operating Manual

Page: 193 / 646

CMU-K20/K21/K22/K23/K24
Signalling: Modulation Measurements
1115.6088.12 4.115 E-12
Measurement Results
The values shown in the measurement menu
Modulation
can be divided into three groups:
•
Setting values
•
Scalar measurement results (single values)
•
Arrays (the measurement curve plotted as a function of time)
The values are indicated in two parameter lines, the test diagram and a tabular overview below:
Parameter line 1 | 2
Test diagram
Output table
Fig. 4-53 Display of results (modulation menu)
In contrast to the
Non Signalling
mode (see p.
4.41
ff.) the first parameter line contains also the PCL of
the mobile station, and the
Timing Advance Error
is indicated. Besides the representation and
interpretation of the results are identical.
Timing Advance
Error
The
Timing Advance Error
output field, which is displayed in the right-hand output
field of the
Modulation
measurement menu, indicates the time offset (in symbol
periods) between the expected and the measured timing of the current burst. The
expected timing results from the timing of the BS signal and the (known) timing
advance of the mobile station.
The
Timing Advance Error
can be determined with trigger mode
Signalling
only;
see
MS Signal
tab, section
Table-oriented Version
on p. 4.160 f.
Measurement Configurations (Modulation Configuration)
The popup menu
Modulation Configuration
contains two tabs which define the parameters of the phase
and frequency error measurement including the error tolerances.
The popup menu
Modulation Configuration
is activated by pressing the softkey
Phase/Err. GMSK
in the
top right of the graphical measurement menu
Modulation
twice. By pressing the associated hotkeys, it
is possible to change between the tabs.
The functions of the
Modulation Configuration
menus are described in section
GSM400/850/900/1800/1900-MS Non Signalling
, see p.
4.50
ff.
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