Salut!
I think our issues are related to the synchronizations parameters
(Costa’s
loop and M&M). It seems that they must be chosen very carefully,
especially costas_alpha and gain_mu.
In order to choose them, I plugged a constellation sink into my
modulator
using GRC. As the constellation sink is using synchronisation algorithm,
I
was able to play with the synchronization parameters and see the
consequences on the constellation.
I would like to learn more about these two algorithms. Where can I find
some interesting reading on the internet?
Eg : for a d8psk, with no gray coding I used : alpha= 0.001 and
gain_mu=0.005
Axel