Center Frequency; Scramble Code - Agilent Technologies 89410A Operator's Manual

Wideband CDMA Concepts (Options B73, B79, and 080)
When selecting a frequency span, select the narrowest span that includes all of your
signal components (select a span that is slightly larger than the bandwidth of your
signal). If you select a span that is too narrow, your measurement may have
excessive errors or the analyzer may lose carrier lock. If the span is less than the
chip rate, the analyzer displays DATA? to indicate that the results may not be
accurate.
For best results, the frequency span should be set according to the following
formula (filter_alpha is the filter characteristic of the Nyquist filter used to
demodulate the W-CDMA signal):
FrequencySpan ≥ (1 + filter_alpha) Chip_Rate
If you select a span that is too wide, your measurement may be affected by
excessive noise and slower speed. You may want to select the Vector instrument
mode and set the span while viewing the spectrum of your signal.
Note
For W-CDMA measurements, the [mx WCDMA span] softkey (press [System Utility],
[memory], [configure meas memory]) limits the analyzer's frequency span.. The value
of this softkey determines the amount of memory reserved for W-CDMA
measurements. For optimum memory usage, set the value of [mx WCDMA span] no
larger than the maximum span that you will measure.

Center Frequency

The analyzer's center frequency must be set within 500 Hz of the center frequency
of your W-CDMA signal, otherwise the analyzer may not be able to lock onto your
signal.

Scramble Code

The analyzer must know the scramble code to demodulate your W-CDMA signal.
You can manually enter the scramble code or you can configure the analyzer to use
an algorithm to find the scramble code from within a scramble-code group. The
algorithm increases measurement time. To minimize measurement time, the
algorithm should only be used when you don't know the scramble code. To setup
the scramble code, press [ Instrument Mode ], [ demodulation setup ], [ scramble code ]. For
additional details about scramble codes, see online help for the [ scramble code ] softkey.
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