Hi, I am trying to plot the BER verses SNR using SVN estimation method (I am using dbpsk.py and dbpsk2.py), but it is not matched with theory. Here is my problems and questions:
1- when I use dbpsk.py with using feedforward_agc_cc I see three centre constellation points, one with the real part around -1.5, one with the real part around 1, and the third one with the real part around 1.5. Is it the problem of using feedforward_agc_cc or I am doing it wrongly? (I tried it many times). 2- When I use dbpsk2.py the constellation points are much more natural, but still they are not appropriate for snr estimation, since the variation of constellation points along the imaginary axis is much less than their variation along the real axis. Another problem here is that the constellation points are not symmetric along the real axis. In fact, one of the centre constellation points has a real part around -0.9 and another around 0.5. Also, the distribution of the points are not completely matched with the AWGN channel assumption (I am using cable). To me it seems that the problems comes from the time_recov part, but I am not sure. Does anybody else have the same problem with this modulation or can anyone help me to solve this problem? Many thanks, Mostafa -- View this message in context: http://old.nabble.com/problem-with-dbpsk-and-dbpsk2-tp28206560p28206560.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
