SDR - Demodulation of DVB-C

Hi Mark,

Transmitter: DTU-215 from Dektec

Transmits 16QAM modulated data at the rate of 4.5Msymbols/s at a carrier
frequency of 578MHz.

Receiver: DTA-2131 from Dektec

Receives 100,000 IQ-samples (16 bit signed integer I + 16 bit signed
integer Q) at the rate of 9Msamples/s (2 samples/symbol) at a carrier
frequency of 578MHz. IQ-bandwidth = 8Mhz.

This should give me 100,000 IQ-samples of 16QAM modulated data at 2
samples/symbol with carrier offset and timing offset + channel distortion
to work with for demodulation.

That is also what I am synthesizing.

Regards,
Viktor

If your solution is working on the synthesized data, then the problem might
be somewhere else. Maybe you can recalculate your filter gains and loop
constants by analyzing your real data again. Or since you have to use an
equalizer, your channel is frequency selective (and not frequency flat).
That means there might not be one optimum pulse for timing phase
adjustment. In that case, your NDA timing recovery module will lock onto
the symbol frequency only (that's what I think is required) and the
equalizer will do the rest.