Design Of Protograph-Based Globally Coupled Ldpc Codes Over The Burst Error Channel

In wireless communication,satellite communication and other communication systems,strong interference and deep fading will lead to sudden errors,seriously damage the quality of communication.As an effective means to improve the reliability of information transmission,channel coding technology has always been a research hotspot in the field of communication.Low Density Parity Check(LDPC)codes are a class of coding techniques whose performance is close to Shannon's limit.Globally Coupled LDPC(GC-LDPC)codes can be considered as a special class of LDPC codes with low error layer and superior antiburst performance.At present,GC-LDPC codes are mostly constructed based on finite field algebraic methods.The steps are complex and not intuitive,and the decoding performance cannot be analyzed with theoretical tools.Protograph-Based GC-LDPC Codes are more flexible in parameter selection and rate design,and have better error performance.In addition,Protograph-Based EXtrinsic Information Transfer(PEXIT)can be used to analyze the theoretical performance and optimize the code structure.Therefore,in order to realize the reliable transmission of information,this paper will study the coding design of ProtographBased GC-LDPC Codes for the scene of burst error channel.The main research work of this paper is as follows:Aiming at the burst error scenario,a new burst error channel model,Additive White Gaussian Noise(AWGN),is proposed to solve the problem that the channel capacity cannot be calculated by the existing channel model and the theoretical analysis is difficult.The channel model combines burst noise and Gaussian white noise,and uses the burst error indicator sequence generated by Gilbert-Elliott model to control the interference of burst noise and Gaussian white noise in the channel to the transmission signal.Then,the steady state condition of AWGN burst error channel is analyzed,and the calculation formula of the channel capacity is derived.In addition,PEXIT graph analysis is extended to AWGN burst error channel,and the detailed steps of optimizing original module graph LDPC code with PEXIT algorithm are given.Finally,the decoding performance of the existing ProtographBased GC-LDPC Code is analyzed by using the PEXIT algorithm,and the anti-burst performance of the code is verified by performance simulation.Aiming at the AWGN burst error channel mentioned above,an irregular Protograph-Based GC-LDPC Code was proposed to solve the problem of high error level in the existing GCLDPC code.In this scheme,a structured irregular prototype diagram is first designed,which is used as the prototype diagram of the initial state.Then,the original model diagram of GCLDPC code was constructed by copying and merging local check nodes,adding global check nodes and making global edge extension,copying and merging global check nodes again.Through the performance simulation results,it is verified that the proposed irregular Protograph-Based GC-LDPC Code has better error performance and lower error layer.In addition,due to the mixed can maximize scattered error pattern,therefore,this article will interweave technology applied to the encoding scheme of irregular Protograph-Based GCLDPC Code.Through performance simulation,it is proved that interleaving technology can further improve the anti-burst performance of digital communication system.