[Discuss-gnuradio] Re: Discuss-gnuradio Digest, Vol 42, Issue 15

[Jens Elsner]

Achilleas,

you can get the data and my matlab test code at:

http://1c3.de/dab_matlab_test.tar.bz2

There are two main matlab files:

dab_tx_mode2.m : Sender and receiver - (almost) works. I'm getting the
correct bits out.

dabtest_mode2.m: Receiver with time/frequency sync using real data. The
constellation diagram looks great - but I don't get any useful bits.
There has to be some kind of error in the symbol mapping or channel
decoding. I'm still looking for the needle in the protocol stack.

Jens

> >Achilleas,
> >
> >great. I'll then focus for now on implementing time/frequency
> >synchronization. Does the decoder support puncturing? Did you publish 
> >you code already?
> 
> The code is generic enough to handle any problem that can be cast as 
> sequence detection for a sequence generated by a trellis. This includes 
> puncturing, sequence detection in the presence of ISI (aka, viterbi 
> equalization), CPM demodulation, etc...
> 
> >Concerning my "jitter" problem: I sampled another DAB source with the
> >DBSRX daughterboard and implemented a correlation based frequency
> >synchronization algorithm. That pretty much solved the problem (although
> >a little jitter is still there). 
> 
> Can you post the data file? I remember that I had tried a correlation 
> based (joint) frequency/time synchronization algorithm with your 
> previous data and it didn't work...
> 
> Achilleas