Message Passing Decoding Algorithm of LDPC Codes—Analysis of Adaptively Selecting Bit Nodes

• Main Authors: Shih-yuan Lin, 林仕元
• Other Authors: Chia-Lu Ho
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/09445587829958285527

碩士 === 國立中央大學 === 通訊工程研究所 === 96 === LDPC code is an error-correcting code which is adopted for the next generation''s advanced communication standard. Its error-correcting ability may approach the Shannon’s theoretical value. With the MP algorithm, it can decode received samples in high speed from transmitter. This algorithm has a good performance in the decoding aspect, but its complexity is higher. Thus, many researchers discuss how to improve complexity without making the performance reduced seriously. In this thesis, the SPA(Sum-Product algorithm) is the best decoding algorithm in soft-decoding to aim at this decoding method which proposes three different ways in the distribution of iteration to do analysis. The method adjusts bit nodes to substitute all bit nodes, and reduces the quantity of operations. When the iteration decoding fails, we increase number of bit nodes and update the message of the check nodes according to the result of the iteration. Finally, its several iterations will return to Sum-Product algorithm. Therefore, it effectively reduces the complexity and without seriously weaken its performance.