Filtering; General Information - Agilent Technologies 89410A Operator's Manual

Filtering

General information

The analyzer uses the same filters for digital demodulation and video
demodulation. For details, see ''Filtering'' in the Digital Demodulation Concepts
chapter, and Note the following differences:
l
You cannot use user-defined filters when VSB is selected.
l
To use user-defined filters with QAM and DVB QAM, the impulse response that
defines the filter must have 20 points-per-symbol and be no longer than 40
symbols, which means the overall length must be less-than-or-equal-to 801
points.
Mirrored Spectrums
Option AYH provides a feature that lets you configure the analyzer's
demodulator to conjugate the complex time-domain waveform. This has the
effect of flipping the spectrum around the analyzer's center frequency. To
enable this feature, select the Video Demodulation instrument mode, then press
[ ], [
Instrument Mode demodulation setup
This feature is often used with VSB measurements that use a high-side pilot.
For VSB signals, the pilot must be on the low-side of the spectrum to achieve
carrier lock. For details, see ''Carrier locking and pilot search: VSB'' earlier in
this chapter.
Video Demodulation Concepts (Opt. AYH)
], [ ].
freq spectrum mirror
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