Blind frame synchronisation for block code

Canal coding can not nowadays be by passed. In order to decode the coded sequence, the receptor has to find the beginning of the codewords. This problem is usually solved by adding periodically to the transmit sequence a frame synchronization sequence. Of course the longer the sequence the better the synchronization but the less the spectral efficiency. We understand clearly the stakes of developing a blind technique that synchronizes before decoding (at high bit error rate) without synchronization sequence. In this article we propose a blind method that allows us to synchronize a block code, we show that it is specially well suited for the LDPC codes and has for those particular code very convincing performance.