Near Optimal BP Algorithm for LDPC-Coded BICM System with EXIT Analysis

A near optimal BP (NOBP) algorithm for low-density parity-check (LDPC) coded M-ary BICM communication system is proposed in this paper. Due to the good code structure of LDPC code, we derive the NOBP algorithm with the generalized distributive law from the generalized M-ary BP algorithm. The simulation results show that the NOBP algorithm outperforms the traditional BICM-BP algorithm over both the AWGN and Rayleigh fading channel. And the EXIT chart of two algorithms confirms the superiority and the fast convergence of our proposed NOBP algorithm.