Re: [Discuss-gnuradio] Two GMSK decoders with two msg queues

[Michael Dickens]

Dawei - A first-order read-over of your code looks good to me; there  
is nothing obviously incorrect - though of course this is just a code  
snippet.  The overall code might have other issues.

On Oct 14, 2006, at 1:22 PM, Eric Blossom wrote:
> I'm not sure what you're trying to do with gr.separator_ccc.  If  
> you're
> just trying to extract two different channels from the complex
> baseband signal from the usrp, gr.freq_xlating_fir works great.

Correct me if I'm wrong, Dawei, but I think this is the scenario:  
there are 2 different transmitters and 1 receiver, all at the same  
(center) frequency and bandwidth.  "separator_ccc" is meant to input  
the single received signal (at baseband), and separate out the 2  
transmissions into 2 streams ... kind of like using different CDMA  
codes, but he's trying out a different algorithm (not CDMA).

> > However, my obeservation was that the two streams produce exactly  
> > the same
> > packets (which are supposed to be produced only by A, not B, the  
> > output of B
> > should be different). So could anyone help me check whether I am  
> > doing
> > things correctly here?
>
> Have you logged the two outputs of gr.separator_ccc into files and
> examined them?  Are they by any chance identical?

I think that's what he's saying, that, yes, the 2 are identical.

I'm guessing that the question is whether or not 2 different GMSK2  
demodulators can run at the same time - since they both use threads  
to do their work and maybe those threads interact in unexpected  
ways.  Or maybe some other issues.

There could also be other issues, but I think those would be with  
this "separator_ccc" block or other programming that we can't see.  I  
would guess he's trying to make sure everything else works before  
going back to debugging that block.  I might be wrong ;) - MLD