Tektronix RSA6100A Series, Help Manual

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GP Digital Modulation > Common Controls for GP
Digital Modulation Displays Advanced Params Tab
Parameter Description
Mag Normalize
(not present for nFSK or C4FM
modulation types)
Select RMS Symbol Magnitude or Max Symbol Magnitude. This setting applies to Mag
Error and EVM.
Swap I and Q When enabled, the I and Q data are exchanged before demodulating.
Symbol rate search
(Present only for nFSK
modulation types) Determines whether to automatically detect or manually set the symbol rate. When
selected, automatically detects the symbol rate to perform analysis. The calculated
symbol rate is displayed in the Signal Quality display. The Symbol Rate Error is also
calculated and displayed when Symbol rate search is enabled.
User Symbol Map (per
Modulation Type) Enables the use of custom symbol maps. This enables you to specify the location of
symbols in the display. This control can be set independently for each of the modulation
types.
xxx
Mag Normalize
Speci fi es whether Magnitude Normalization uses the RMS Symbol Magnitude or the Maximum Symbol
Magnitude as the basis for normalization. Use RMS Symbol Magnitude on QPSK modulations (equal
magnitude symbol locations), and use Maximum Symbol Magnitude for signals that have a large difference
in magnitude among the symbol locations (such as 128QAM). It prevents the instrument from using the
very low magnitude center symbols when normalizing the constellation. The outer symbols are a better
normalization reference than the center in this case.
Swap I and Q
Use the Swap I and Q control to correct a signal sourced by a downconverter that inverts the frequency
of the signal under test.
User Symbol Map
A User Symbol Map is a text fi le that speci fi es the location of symbols in the display. The symbol map
is unique for each modulation type. The easiest way to create a custom symbol map is to start with
the default symbol map and modify it. The default symbol map
fi le is located at C:\RSA6100A Files.
The default symbol map fi le is named DefaultSymbolMaps.txt . See Symbol Maps (see page 270) for
illustrations of the default symbol mapping.
To specify a user symbol map:
1. Click the ... button.
2. Navigate to the directory containing the user symbol text fi le you want to use.
3. Select the desired fi le in the Open window and click Open .
4. Select User Symbol Map to enable the user symbol map.
Editing the User Symbol Map.
The symbol map is a plain text fi le and can be edited with any plain text
editor.
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RSA6100A Series Real-Time Spectrum Analyzers Help