[Hackrf-dev] PHASE CHANGE

[Cinaed Simson]

Recovering the information in a BFSK signal is a software problem on a SDR.

Also, they are typically noisy and use Manchester encoding to recover
the clock rate.

You should post this on the SDRsharp mailing list - and knowing the
transmitting device and a FFT of the resulting signal on the HackRF
would be helpful.

And did you use a low pass filter - what was the cut off frequency and
transition width - and did you avoid the DC offset on the HackRF?

And how did you determine it was a FSK and not a PSK signal?

The idea is to use the SDR to analyze the I/Q values captured by the
HackRFs.

-- Cinaed

On 03/30/2017 03:45 AM, Ernest Matey wrote:
> Experts,
> 
> I have two hackrfs receiving the *same* voice transmission on FSK -1200bps
> I expect and plan to see the same modulation signature from the two
> systems of this same signal.
> I did *Raw* IQ recording with SDRsharp with the following parametrs.
>  
> Tx Freq - 437 MHz
> Rx Freq - 437 MHz
> Bandwidth - 10 KHz
> Samp - 12.5 MHz , 8bit
> Black-Harris filter
> Freq_correction -     -2ppm
> 
> BUT, I do not see the same phase signature of the signal even though I
> align the bursts in time.  I expect to see same pattern
> 
> *See attached plots of same channel each from the two hackrf systems.*
> *
> *
> *What could be done ?
> *
> *
> *
> *Ernest*
> 
> 
> 
> 
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