R&S FSH
Digital Modulation Analyzer
Measurements on CDMA2000 Signals
Operating Manual 1309.6275.12 - 14
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7.3.5 Configuring the Measurement
Some of the results depend on the measurement configuration.
7.3.5.1 Setting the Base Spreading Factor
The number of codes the R&S FSH displays in the diagram depends, in addition to the
signal constellation itself, on the base spreading factor you have set.
M
Press the MEAS key.
M
Press the "Signal Settings" softkey.
M
Select either the "64" or "128" menu item.
The R&S FSH applies the corresponding spreading factor to the measurement. A
base spreading factor of 64 results in a display of 64 codes on the x-axis (0 to 63),
a base spreading factor of 128 in a display of 128 codes on the x-axis (0 to 127).
In the code domain analyzer result display, the number of displayed codes
changes accordingly.
Take care of setting the base spreading factor of the code domain to either 64 or 128.
If you set the base spreading factor to 64 for channels with a base spreading factor of
128 (code class 7), an alias power may be displayed in the Code Domain Power result
display, because of the ambiguity of the Hadamard Matrix. An alias power is a
displayed code power, where no power would be if the spreading factor was correct.
7.3.5.2 Changing the Code Order
The code order defines the order the codes are displayed.
Hadamard order means that there's no distinction between channels. The R&S FSH
shows codes in ascending order regardless of the channel that it belongs to.
BitReverse order means that the R&S FSH combines codes of a channel if a channel
consists of more than one code. When using BitReverse order, the codes of a channel
are next to one another. In this way you can see the total power of a concentrated
channel.
