Hi all,
I managed to modify the viterbi code from C-CODE/SUB_DC.C in the ZIP file from the 300 395-2 spec. It implements a different mother code (i.e. the voice code which is a rate 1/3 code, whereas signalling uses a rate 1/4 mother code).
So far I am not really getting much out of it. Sometimes some parts of the bursts make sense (like the 0/1/2/3/0/1/2/3/... sequence of frame numbers), but stuff like MCC/MNC gives completely bogus values.
I'm too tired now to continue, will look at it again tomorrow. But I think we're close.
I will commit the code as soon as something is working at all.
My next attempt is to try to run this viterbi against bursts that I generate using my code. If that works, then we must be doing something wrong in the lower steps (de-interleaving, de-puncturing).
Regards, Harald