Steven Clark wrote: > Hi all- > please look at this sequence of eye diagrams: > http://picasaweb.google.com/steven.p.clark/GMSKFmdemodGlitches > > These are from a gmsk mod/demod pair, showing the output of the TX's > gaussian filter (blue) overlaid with the output of the RX's fmdemod > (red). BT = 0.35. > > At 8 samples per symbol, everything looks ok. Red is pretty much right > on top of blue, as we'd expect. > As I increase samples per symbol, however, something strange happens, > shown in plot sequence. The RX's fmdemod output gets successively more > "glitchy".
One other thing -- you really shouldn't be going to more than 8:1 oversampling on GMSK anyway -- all the timing recovery stuff will have trouble with that high of an oversampling rate when you have noise on the signal. We still need to fix this problem, but I would advise staying at 8:1 or lower. Your bandpass filtering also becomes harder at the higher oversampling ratios. Matt _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
