Hi
I just did PDR testing between two USRPs with D8PSK modulation scheme. The files I used are benchmark_rx.py and benchmark_tx.py. Two exceptional results confused me a lot:
1, the --tx-amplitude has to be adjusted to the default value (12000), with which the PDR could reach 100%, otherwise, if 10000 were used, the PDR would experience a huge slump (around 40%). This phenomenon never happened to DQPSK.
2, For indoor testing, the distance between two USRPs should be less than 1 meter. In 1.5 meters, the PDR would also plunge a lot.
Is there any problem with the D8PSK in Gnuradio? Should I modify the parameters of the carrier tracking and timing syn circuits? The --costas-loop I used was 0.05 with gain-mu set to 0.001 which worked very well for
DQPSK.
Thanks!
Bill