Hi all,
in TETRA, the only part of the signal that is transmitted with a well-known scrambling code is the BSCH in the SB1 (first half of the downlink SYNC block). We can finally decode that since yesterday and get proper MCC/MNC and TDMA time information.
The colour code + MNC + MCC is used as the scrambling sequence for all other messages of the cell, specifically also the BNCH containing the SYSINFO messages.
I've recently added code to indicate when a BNCH block is to follow, but the de-scrambled type-2 bits do not look plausible at all.
So there's most likely still some problem with the de-scrambling. The de-interleaving, de-puncturing and viterbi decoder are the same code (even with different parameters), so I don't think that there are likely problems caused by them.
Regards, Harald