[Hackrf-dev] FSK & PSK

[김상혁]

my flow graph like below:

Tx) 
file source (txt file) -> packet encoder (bit per symbol = 4) -> 16QAM modulation -> osmocom sink

Rx)
osmocom source -> 16QAM demodulation -> packet decoder -> file sink


> 2015. 12. 1., 오후 7:17, Dominic Spill <dominicgs at gmail.com> 작성:
> 
> On 25 November 2015 at 05:54, 김상혁 <tkdgur7896 at gmail.com> wrote:
>> 
>> I am wondering why most of file transfer use FSK (De)Modulation scheme ?
> 
> I'm not sure what you mean by "most file transfer", do you have a
> particular device/application that you are targeting?  Or are you
> trying to build your own system?
> 
>> I tried to replace GMSK to QAM or PSK scheme, however it doesn’t work.
> 
> Could you provide us with any more informationt han this?  The
> flowgraphs?  The way that they fail?
> 
>> I couldn’t get any file,but when I saw Rx GUI FFT Sink, I could see signal is sparked at Tx started.
> 
> Have you tried to debug this?  I would start by taking out the radio
> blocks and writing the samples to file, then reading it back.  This
> will make sure that your modulation/demodulation are working as
> expected.
> 
> After that you will need to look at the FFT (as you are already doing)
> and maybe a waterfall plot to see if there is noise that affects your
> signal.
> 
> You could record the received data to file and view it with inspectrum
> to see if it looks as you expect.  Is there noise?  Is the entire
> signal present?