2
$\begingroup$

Currently trying to transmit a BPSK and a 4-FSK(MFSK) signal via GRC using USRP, I have two attempts at it but don't seem to be going anywhere. Still fairly new to GRC. For the BPSK, how will this signal appear on the spectrum analyzer? I have seen general images of the signal shape online but pretty sure what I see is not it. Will I be able to hear the BPSK signal, if so what will it sound like?BPSK Flowgraph

As for the 4-FSK, I seem to have something but the spikes I generate are at different amplitudes in comparison with a FSK signal I had generated a while ago that had the spikes at the same/similar amplitudes.4FSK Flowgraph

I can share my flowgraphs if it helps. Also it would be great if anyone had known working flowgraphs for these concepts to share for comparison or even be able to edit some features of mine. As for the details I care about, I really need to be able to specify the excursion/deviation between the spikes.

$\endgroup$
5
  • 1
    $\begingroup$ Hello and welcome to ham.stackexchange.com! $\endgroup$
    – rclocher3
    Mar 3 at 16:45
  • $\begingroup$ Not much we can do to help besides pointing you towards google results for "gnuradio psk tutorial" and "gnuradio fsk tutorial" unless you share your flowgraphs. $\endgroup$ Mar 3 at 17:19
  • 1
    $\begingroup$ @PhilFrost-W8II Just added them. Sorry it was my first time posting here $\endgroup$
    – lceans
    Mar 4 at 14:16
  • 1
    $\begingroup$ Hi. If you're just starting to use GNU Radio and don't have any legacy body of GNU Radio flow graphs to work from: Don't use GNU Radio 3.7, it's legacy-only by now. 3.8 and even 3.9 is easy to install on any modern Linux, and on OS X and on Windows (on the latter especially using anaconda makes it really easy). I'm saying that because it really took us years to get 3.8 out – and now you're starting with something that I'd call "deprecated", making it hard for you to find other knowledgeable people doing the same. $\endgroup$ Mar 8 at 15:15
  • $\begingroup$ @MarcusMüller Thanks for the heads up but I am stuck with 3.7 as its a requirement for my use case. I have been using 3.8 and 3.9 to learn more up to date methods aside from this $\endgroup$
    – lceans
    Mar 8 at 16:44
0
$\begingroup$

There are a lot of ways to make those transmitters, but I think for a beginner the simplest options are:

You can also check the examples here: Collection of GNU Radio Companion Flow Graphs

$\endgroup$
1
  • $\begingroup$ Thanks for the reference to the collection that will be helpful in some way in the future. As for the FSK example I have built that before but not super sure on how to make that 4FSK. As for BPSK, I have seen some use the constellation modulator block and others the PSK Mod block. Is there a benefit of one over the other? I have my flowgraphs posted if you have any feedback on those $\endgroup$
    – lceans
    Mar 4 at 14:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.