Abstract:

On iterative phase synchronization algorithm by using irregular low-density parity check (LDPC) codes is proposed based on the analysis of the symbol prior information on EM algorithm. Due to close connection between decoding information and convergence behavior of the EM algorithm, the new proposed algorithm makes use of inherence property of unequal degree distributions provided by irregular LDPC codes. The high-degree nodes of irregular LDPC codes tend to correct their value more quickly and offer more reliable prior information to EM synchronizer, which can improve the convergence performance of the EM synchronizer. The simulation results indicate that the EM iterative synchronizer by using irregular LDPC codes can achieve larger carrier phase estimation range and faster convergence rate.