Joint frame synchronization and belief propagation decoding for quasi-cyclic LDPC-coded system under pseudorandom noise disturbance

Because of the quasi-cyclic nature of Quasi-Cyclic LDPC (QC-LDPC) codes, there are ramps in the frame synchronization searching process. A pilotless code-aided frame synchronization algorithm joint with improved BP decoding for QC-LDPC coded system under PN disturbance to eliminate the ramps is proposed in this paper. Simulation results show the validity of the modified BP decoding algorithm and outstanding synchronization performance compared to the algorithm before improvement and hard decision frame synchronization proposed by Dong-U Lee.