Re: Osmocom Source (frequency deviation)

[Artur Nogueira]

Hi Jeff,

Thanks for the feedback.

I'm using GNU Radio Version 3.7.13.5 and two Great Scott Gadgets HackRF units for the transmission/reception.

My workflow looks like this:

Do you usually use any artifact to compensate for this frequency shift?

I'm afraid this could affect demodulation and therefore the BER.

Best regards,

Artur 

Em qua., 24 de jun. de 2020 às 16:31, Jeff Long <willcode4@gmail.com> escreveu:

Artur,

You haven't mentioned what software you are using, how you have it configured, or what your flowgraph looks like.

If you are using two SDRs and the frequency difference is a few kHz, then that is just oscillator differences.

On Wed, Jun 24, 2020 at 3:12 PM Artur Nogueira <artur.nogsj@gmail.com> wrote:

Hi everyone,

I'm comparing the spectra of a pair of transmitted/received GMSK signals (carrier frequency = 923 MHz).

As expected, there is a certain channel attenuation.

Nevertheless, there is this frequency deviation at the Osmocom Source output:

I suppose this is something related to the receiver hardware.

Do you have a suggestion on how to compensate for this effect at a software level?

Best regards,

Artur