Principles And Application In BICM Of LDPC Codes

In this paper, we introduce the development of digital communication system and channel coding. On the basis of explaining principles and characteristics of LDPC codes and BICM, we carry on further investigation on encoding and decoding algorithms of LDPC codes and BICM system based on LDPC codes.Research on fast encoding of LDPC codes, especially on fast encoding method and encoding circuit of QC-LDPC codes. Analyze the decoding algorithms (log-likelihood radio) of LDPC codes and compare with sum-product algorithm, min-sum algorithm, modified min-sum algorithm and hard decision bit flipping algorithm in complexity and performance. Analyze BICM and BICM-ID in details and derive iterative process of BICM-ID based on LDPC codes. Research on influence of interleaver and labeling maps on the performance of the system by simulation and get a labeling map suiting this system.We also research on the effective method analyzing convergence of iterative decoding——EXIT chart. Analyzed the iterative process of BICM-ID based LDPC codes and the influence of some labeling maps on the system performance by EXIT chart in AWGN channel and rayleigh channel, we validate the conclusion which is got by simulation.