Special Considerations For Pulsed Signals - Agilent Technologies 89410A Operator's Manual

Digital Demodulation Concepts (Opt. AYA)

Special considerations for pulsed signals

Pulsed transmissions are generated by on/off (or burst) carriers such as those used
in mobile units. For this type of signal the analyzer searches within the defined
search length to locate the first complete pulse which can occur anywhere in the
search length. Pulses beyond the first complete pulse are disregarded and are not
demodulated. In order for the pulse search algorithm to detect a pulse edge, the
pulse must be at least 15 dB above the noise floor. The resultant pulse is then
demodulated. If sync search is selected in addition to pulse search, the analyzer
performs pulse search first then performs sync search on the resultant
demodulated pulse as illustrated below.
See "Using Digital Demodulation" earlier in the book for an example of using pulse
search and related features. See online help for key-specific information related to
pulse search.
The result length, which includes both the offset and the sync word, must not violate the
boundaries of the demodulated pulse.
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