Hi!
As it turns out, my fibonacci and galois form of the scrambler
do not generate the same bit pattern. I originally tested and
verified they produce identical results - but apparently they don't.
We now have successful decoding of all the SYNC bursts in the sample
capture, as you can see from the attachment.
Whenever there's a gap in the decoded FN, this is due to a NORMAL burst being
transmitted instead. The normal burst does not carry the timeslot/framenumber
information and we need to count ourselves in the gaps in between.
I am already computing the scrambling sequence init value from the
MCC/MNC/CC that we receive in the SYNC burst, and de-scramble the BBK
and BLK2 of the SYNC burst. However, the viterbi has not been adapted
yet to the encoding of those bursts (it's not much).
I'll update you once we can decode more...
--
- Harald Welte <laforge(a)gnumonks.org>
http://laforge.gnumonks.org/
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