On Thu, Sep 20, 2012 at 9:56 AM, Kyle Zhou <kyle...@gmail.com> wrote: > 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
Hi Kyle, I was using this just last week in a demonstration and hadn't noticed any problems. If you can pin-point what's going wrong, though, I'll be sure to fix it. Tom _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
