Research On A Low Complexity Floating Point Algorithm Based On LDPC-CC In Metropolitan Area Network

With the expansion of metropolitan area network and the rapid increase of business volume,the influence of random errors and burst errors on transmission performance is becoming more and more prominent.The new generation of man has put forward higher requirements for channel coding.Forward error correction code(FEC)using redundant check bits in the transmission data to determine whether there is error and when the error exists to do error correction decoding accordance with the specific rules at the receiver is a stable,practical and efficient method of error correction that can improve the reliability of information transmission.Based on the research of the correlation,construction and encoding and decoding process of RS codes,LDPC-CC codes and product codes,this paper focuses on the study of construction of product codes based on RS codes and LDPC-CC codes,and the low complexity truncated decoding algorithm and puncturing algorithm.The main work is as follows:(1)Based on the research of the structure model of optical communication system in metropolitan area network and the research of the construction methods,basic characteristics and encoding and decoding principles of RS codes and LDPC-CC codes,a channel coding scheme using RS codes and LDPC-CC codes to design product codes is designed.The product codes implement self-interleaving coding using RS as the outer code and LDPC-CC code as the inner code.The research results show that the product code scheme can effectively improve the error correction performance.(2)On the basis of studying the complexity of product code,a truncated decoding algorithm on RS-LDPC-CC product code is proposed.This method adjusts the length of the truncated code word in time by monitoring the channel condition to reduce the complexity and improve the efficiency.The simulation results show that the truncated decoding algorithm can effectively reduce the complexity in the coding and decoding process with ensuring good error correction performance.(3)On the basis of studying the actual change of channel capacity in metropolitan area network,a variable rate puncturing algorithm is proposed by constructing a product parity check matrix based on the weight reforming of column codes.This method change the code rate according to the specific condition of the time-varying fading channel,so that the channel throughput is maximum.The simulation results show that the puncturing algorithm reduce the coding and decoding complexity in the time-varying channel and improve the throughput rate of the channel.