libosmocore viterbi decoder

Sylvain Munaut 246tnt at
Thu Apr 28 19:16:46 UTC 2011


> Like I said I would try to, here are my computed convolution tables for all eight AFS modes.

I didn't check them all but they don't look good because they're at
least missing the proper termination.
When the code is systematic it's not terminated the same way as a
non-systematic code and so you need some special termination handling.

See in attachement for my version. (and I know it works :p)

I don't want to just include the table in libosmocom, I'd like to
include the generator itself and build them as part of the build
process and for that I still need to write it to output nicely
formatted C code :p

> What I meant was performance not in terms of speed but in terms of decoding quality.
> As you wrote not to have error added where is none. It should improve correct decoding of weak signals by some slight degree.

Well since that error is constant I'm not sure it'll help that much.

But at least the decode will not return a != 0 value if there was no bit errors.


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