> Date: Tue, 22 Jan 2019 10:42:19 +0100 > From: samuel verdon > > hello Everybody, > > I am trying to recover my fsk signal with the Muller&muller block. > Here is my configuraiton: > Sample rate of USRP = 240K > bitrate of signal = 9600bps > > receiving the signal from the USRP, > apply a low pass filter -> quadrature demod ->rational resampler -> > m&m > sync block > > > My signal contain a preamble of 100ms of 1010 (0x55). after my > Muller&Muller block, I can see the recovering working for my signal > but not > for my Preamble. I have pulse on the preamble which sometime are > visible on > the data part as well. > https://ibb.co/hfLt62K <https://ibb.co/hfLt62K> > https://ibb.co/xqRkRP7
The M&M Timing Error Detector (TED) gain collapses to 0 when operating on "clock patterns" of 1010101, so the M&M TED works horribly on trying to acquire such a preamble. > I have tried also with Polyhpase clock sync block but this one took > to > much time to be syncronised with my preamble. > > Can someone help me by explaining this pulse? I porbably do not use > correctly the sync block ( I have left the default value except for > the > omega=sps ). Can someone redirect me to a documentation to use it > correctly? > let me know if I have to give more information. Switch to using the Symbol Synchronizer Block. You should read this brief: https://www.gnuradio.org/wp-content/uploads/2017/12/Andy-Walls-Samples-to-Digital-Symbols.pdf And read my recent comments in this GNURadio Issue: https://github.com/gnuradio/gnuradio/issues/2134#issuecomment-456238039 Regards, Andy > Thank you in advance for your help > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
