Hi again, not sure to post my question here or in the Decoder-part...Let's see what comes out; I am in the process of building a same type of decoder as is used to decode the simple AMB-type transponders for which the whole threat was initiated: BSK-coded AMB-MX transponders used in motorcross events. I have my system operational for the regular AMB-transponders (see few posts of my implementation here as well as for my decoder in the other threat).
Using a Rohde&Schwarz FSIQ analyser and a AMB-MX transponder, we discovered a row of bits that appear in every burst. This seems to us as if it is the System-ID. The remaining bits in every burst is every time different. The FSIQ analyser can be programmed to trigger on this 'preamble', so we were able to log the complete burst. Sampling 10 bursts showed 10 different messages (but of coarse 10 times same preamble). We tried to match the transponderID to the 'message' bits, but did not succeed...
Our question is: In case an encryption is used, would the message be every time different despite the transponderID is every time the same? Is the coding probably the 'Convolution Code' that was meantioned earlier? If so, can someone share info how to decode the messages we have logged?
Thank you for taking time to answer, Gerrie