On Mon, Apr 14, 2014 at 01:25:48PM +0200, Andre Puschmann wrote: > > Attached is a screenshot of a GRC waveform I used to capture the > preamble of a single packet. Channel 2 is simply the output of a > quadrature demod block connected to a scope GUI block. I'd like to > decode that into a sequence of bits to run preamble detection etc. > > I've seen a few OOT modules that do similar stuff but was wondering if > there is a GR'ish way to this, maybe a set of generic blocks that > could be used for that?
It looks like you are on the right track! For the next steps, I recommend a low pass filter (with perhaps 20 kHz cut-off) followed by M&M clock recovery and binary slicer. Check out the recent "ASK demodulation help" thread for more details. Try setting the decimation of the LPF to something that gives you 2 to 5 samples per symbol. Your graph looks like the preamble is at about 1.92 kbps, not 19.2 kbps, so I suspect that you have an error somewhere in your sample rate configuration. Mike _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
