Re: [Discuss-gnuradio] Decoding FSK modulated signal

[Andre Puschmann]

On 04/14/2014 05:40 PM, Michael Ossmann wrote:
> 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.


Hi Mike,

thanks! That's exactly what I was looking for. I think I have to play
around with the synchronizer settings but the results are already quite
promising.

I'll keep you updated.

Thanks again
Andre