Research on Symbol Synchronization Technology of LDPC Coding System

Abstract

In this paper, the influence of initial estimation of symbol synchronization error and signal-to-noise ratio on the performance of LDPC coding system is analyzed. Combined with the statistical characteristics of iterative decoding output soft information, a symbol synchronization joint signal-to-noise assisted by iterative decoding soft information is proposed. The ratio estimation algorithm combines symbol synchronization, signal-to-noise ratio estimation and iterative decoding through two closely related loops. Through the iterative calculation, signal-to-noise ratio and symbol in the case of extremely low signal-to-noise ratio The estimated value of the synchronization error can be quickly converged, and the decoding performance is close to the coding system with known signal-to-noise ratio and accurate symbol synchronization.