Instrument Functions for Vector Signal Analysis
R&S
®
FSV-K70
195
Operating Manual 1176.7578.02 ─ 09
When you align the result range to a bursted signal, due to the uncertainty of the
burst search, the determined result range might start up to 2 symbols before or
after the actual burst. However, an offset of only one symbol has the effect that
none of the predefined symbol sequences in the Known Data file will be found. To
avoid this, try one of the following:
–
Align the result range to a pattern instead of the burst.
–
Use a precise external trigger and align the result range to the capture buffer.
This requires a very precise trigger timing, otherwise the result range start may
be incorrect again.
●
Continuous signals
For continuous signals without a pattern, the result range is aligned randomly.
Thus, a very large number of possible sequences must be predefined.
Use a precise external trigger and align the result range to the capture buffer. This
requires a very precise trigger timing, otherwise the result range start may be incor-
rect again.
3.3.7.2
How to Load Known Data Files
Known Data files are loaded in the "Modulation & Signal Description" settings.
To load an existing Known Data file
1. In the "Settings Overview", select "Modulation / Signal Description".
2. Switch to the "Known Data" tab.
3. Activate the usage of a Known Data file by selecting the "Known Data" option. This
enables the "Load Data File" function.
4. Select the "Load Data File" button.
A file selection dialog box is displayed.
5. Select the xml file which contains the possible data sequences of the input signal.
The file must comply with the syntax described in
Known Data File Syntax Description"
The header information of the xml file is displayed in the dialog box.
Once a Known Data file has been loaded, the Bit Error Rate result display
becomes available.
If the "Fine Synchronization" setting in the "Demodulation" dialog box is set to
"Auto" mode, the known data is also used for synchronization. Otherwise it can be
selected manually. Defining a maximum symbol error rate for the known data in ref-
erence to the analyzed data avoids using a falsely selected or unsuitable file for
synchronization (see also
3.3.7.3
How to Create Known Data Files
You must create the Known Data files yourself according to the possible data sequen-
ces of the input signal. Use any xml editing tool you like, following the rules described
in
Chapter 3.3.7.4, "Reference: Known Data File Syntax Description"
Configuring VSA Measurements
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