文档介绍：西安电子科技大学硕士学位论文多进制QC-LDPC码编译码算法研究姓名:谢大平申请学位级别:硕士专业:密码学指导教师:葛建华 20100101 摘要多进制准循环LDPC()是一种重要的LDPC码,它同时具有准循环LDPC和多进制LDPC的性质。。,首先研究了基于消息传递的多进制和积译码算法;其次分析了基于对数似然比的和积译码算法;同时分析了一种基于分段线性逼近的简化译码算法,该算法能降低译码的复杂度。,首先总结了传统的LDPC码构造方法,其次研究了基于有限域的 。LDPC码的构造算法;,它们利用了特殊的循环移位矩阵和矩阵弥散。仿真结果显示,在AWGN 硬判和KV软判译码算法的RS码具有更好的性能。关键词: 多进制准循环LDPO码有限域多进制和积译码算法矩阵弥散 ABSTRACT Inheriting the benefits ofboth non-binary LDPC and quasi—cyclic LDPC codes, non-binary quasi·—cyclic·-LDPC(NB--Qc··LDPC)codes are particularly important sub·class ofLDPC thispaper,research on construction and decoding algorithm of NB—QC-LDPC ,the Sum-Product algorithm ofnonbinary LDPC codes based on beliefpropagation ,the sum-product decoding algorithm ofnonbinary LDPC codesbased 011log-likelihood , ansimplifieddecodingalgorithm based onthe linearapproach metl叠od isproposed, decoders with forthe construction of LDPC codes,the construction methods ofconventional LDPC codes alesummarized ,the construction algorithms ofNB-Qc·LDPC codes over GF(q)field arediscussed. Finally,efficiently encodable NB·-Qc··LDPC codes isanalyzed,which arebased on arrays ofspecialckculantpermutation matrices over GF(q)fields and dispersions resultsshow thattheconstructed codesdecoded谢m iterativedecoding usil蟠that the constructed codes decoded wim iterativedecoding using theFast Fourier Transform based on q-aryLDPC(FFT-QSPA)perform well OVertheAWGN and othertypes theAWGN channel,the constructed codessignificantlyoutperform the RScodes ofsamelengths and ratesdecoded with thehard-decisionBerlekamp-MasseyIB№or algebraic soft-decision KotterVardy(KlO algorithm. Keywords:Nonbinary Quasi-cyclic LDPC codes Nonbinary Sum-Product Algorithm Galois Field Array Dispersions 西安电子科技大学学位论文独创性(创新性)声明秉承学校严谨的学风和优良的科学