I adapted my codes from gnuradio-3.3 to the new 3.6 version. One of the changes is the new digital.costas_loop_cc is now implemented based on control_loop. The costas loop is used for phase recovery of a QPSK signal. But I noticed that with the new version, the output experiences a lot of phase slips. To be exact, the phase at the output rotate 90 degree from time to time. I changed it back to the old gr.costas_loop_cc and this did not happen. The setting for the old loop is alpha=0.01, beta=alpha*alpha/4, max_freq=2*pi*0.1, min_freq=-max_freq. The setting for the new loop is loop bandwidth = 2*pi/100
The new version is only good when SNR is very high, say 13dB+ Any has encountered the same problem? or am I doing something wrong? KZ _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
