Study And Implementation Of Low Density Parity Check Codes Encoding And Decoding Algorithm

Achieving reliable communication approaching Shannon's capacity limit at effective power cost in the ultimate object of modern channel coding technique. The invention and development of low-densiy parity-check codes (LDPC) narrow the gap between real system performance and channel capacity. Combining the existing theoretic and practical fruits, researchers focus on the designing of powerful LDPC codes with low coding and decoding complexity.The linear block code is called a binary low-density parity-check code if it is based on a sparse parity-check matrix. This sort of code was originally proposed by Dr.Gallager in 1962, which cannot attract a large amount of interest at that time. However, it is now rediscovered by Mackay and Neal, along with the development of computer and some relative theory. It is also shown that the performance of LDPC codes is close to the Shannon limits when combined with BP decoding algorithm. LDPC code has drawn the worldwide attentions in channel coding community due to its high performance and strong potential applications in practice. So far, it is considered the best performance error-correcting codes.The thesis mainly introduced the encoding and decoding of LDPC code, also the performance analysis of the algorithms, are studied, with a theoretic analysis and an experimental simulation. At last, a platform of LDPC encoding/decoding simulation system over AWGN channel is proposed based on Simulink. Moreover, it analyzes different parameters for the performance of LDPC codes and draws some conclusions.