Hey Fred,

nice to have you around!

Could you maybe post a screenshot of the frequency plot so that we can
evaluate what you mean with "huge"?

I think you might not be realizing that DSP like GNU Radio does it
doesn't care about the number you set as sampling rate – i.e. a GMSK
symbol in the configuration you're using of the GMSK mod will always be
2 samples long. And that is what defines the shape in the spectrum. So,
the frequency axis in your frequency plot is really just
-bandwidth;+bandwidth _labeled_.

Best regards,

Marcus

On 04/20/2017 07:19 PM, Fred Castello wrote:
> Hi there,
> My goal here is to ultimately develop a telemetry system but I am
> starting very simply by building a GMSK encoder using a file sync fed
> directly to a decoder.  It seems to be working as I can see the
> constellation diagram (which eventually goes away-dont know why) and
> on the scope sync I can see the phase transitions but in the FFT sync
> it appears that the bandwidth is huge.  From what I understand, I
> would not want to filter the results going from the modulator to the
> demodulator, but I may not understand that correctly.  I know I have a
> long way to go, but I am just trying to learn as I go and try to
> figure out the theory and see how it applies as I build using GNU
> radio.  Thank you anyone for your help!!  I am including the Flow
> Graph as well as the test file that I am using for the file sync. Much
> appreciated.
> Fred
>
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> [email protected]
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

_______________________________________________
Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Reply via email to