Research of LDPC Decoding Based on Modified LLR BP Algorithm
Hua Qu · Journal of Southwest University · 2009
The Tanner graph of long LDPC codes usually has no loops and LLR BP algorithm is the best soft-decision decoding algorithm.But the Tanner graph of short LDPC codes usually has loops,so information within variable nodes doesn't satisfy the condition of independent identical distribution and the decoding performance of LLR BP algorithm will decrease.In this paper,a modified LLR BP algorithm is proposed,which can reduce the relativity of information within variable nodes by adjusting the iterative process of variable nodes information.Simulation results show that the LDPC decoding performance of the modified LLR BP algorithm is more effective than that of LLR BP algorithm,Normalized BP algorithm and offset BP algorithm.