Digital Demodulator Block Diagram: Qam And Dvb Qam - Agilent Technologies 89410A Operator's Manual

Video Demodulation Concepts (Opt. AYH)

Digital demodulator block diagram: QAM and DVB QAM

Selecting Video Demodulation reconfigures the analyzer's digital demodulator
to demodulate video signals.
The following illustration shows the digital-demodulator block diagram when
QAM or DVB QAM is selected. The block diagram is identical for both
demodulation formats, with the following exceptions:
l
Bits are decoded differently.
l
I/Q origin offset is removed from QAM measurements. I/Q origin offset is not
removed from DVB QAM measurements (but it is reported in the symbol table).
If you're familiar with digital demodulation, you may notice that 16 QAM and 32
QAM are available in both digital demodulation and video demodulation modes
(see table below). You can use either mode to demodulate these QAM formats.
However, note that DVB QAM measurements do not remove I/Q origin offset
whereas QAM measurements do remove I/Q origin offset.
Digital Demodulation
(option AYA)
ü
16 QAM
ü
32 QAM
64 QAM
256 QAM
23 - 4
Video Demodulation
(option AYH)
ü
ü
ü
ü