Extended recursive soft sequential estimation of m-sequences

A new type of recursive soft sequential estimation (RSSE) algorithm is presented. The algorithm can be used for fast initial synchronization of pseudonoise (PN) signals based on m-sequences. The key feature of the algorithm is the grouping of binary symbols and the reception of the group as a whole symbol. Different numbers of binary symbols in the group lead to different estimation algorithms in a noisy environment. We showed the equivalence of a full parallel search algorithm and the proposed one when the number of binary symbols in the group is equal to the length of shift register in m-sequence generator. The complexity of the algorithm does not depend on the length of shift register and exponentially grows with the number of binary symbols in the group. Bearing in mind the above remarks the proposed RSSE algorithm is suitable for initial synchronization of long m-sequences. The simulation showed that the acquisition time becomes shorter when the size of the group is larger.