I am using bladerf in loopback mode with a 20 dB attenuator.
I am trying to implement QAM modulation-demodulation and I have attached
the flowgraph I am using.
The problem is I am not getting the demodulated data.
I have used the same flowgraph for DBPSK,DQPSK, etc.
Any idea why it is not working for QAM ?
Also the QAM demod block has a parameter phase bw. In PSK demod, Costas
Loop is used, but costas loop cannot be used for QAM so how is phase
synchronization done for QAM ?
Thanks for any advice.