Blind estimation of spread spectrum codes for LC-DS-CDMA signals based on BCH code error correction and Fast-ICA

Aiming at the problem of the spread spectrum codes blind estimation of the LC-DS-CDMA signal in non-cooperative communication, firstly, the synchronously received signal was segmented according to the spread gain which has been estimated in advance, and then the m sequence spread codes fragments were estimated based on Fast-ICA algorithm from the received signal fragments. Secondly, the estimated fragments were spliced into all possible sequences. Thirdly, the part of the combined sequences were removed roughly based on the autocorrelation of the m sequence, and then a small part of sequences were selected based on the triple correlation of the m sequence from the rest of the sequences. Finally, the equivalence principle between the BCH code and m sequences was used to correct the combined sequences. The successfully error-corrected sequences were the spreading code sequences and the sequence that has been corrected was the estimated sequence. The simulation results verify the effectiveness of the proposed algorithm.