搜索
目录摘要...........................................................................................................................(1)1绪论.........................................................................................................................(3)1.1无线通信发展状况........................................................................................(3)1.2LDPC发展动态.............................................................................................(5)1.3本论文的主要工作.......................................................................................(5)2LDPC码的原理.......................................................................................................(5)3LDPC码校验矩阵构造...........................................................................................(6)3.1校验矩阵的随机构造....................................................................................(7)3.2校验矩阵的结构化构造................................................................................(9)4LDPC码的编码.....................................................................................................(11)4.1密集编码......................................................................................................(11)4.2LU分解........................................................................................................(11)4.3高斯消去.....................................................................................................(12)4.4LDPC码的有效编码...................................................................................(12)5LDPC码的译码.....................................................................................................(14)5.1BP译码........................................................................................................(14)5.2降低复杂度的BP译码..............................................................................(16)6运用MATLAB对LDPC码仿真........................................................................(20)6.1不同码长对LDPC码的影响......................................................................(20)6.2不同迭代次数对LDPC码的影响..............................................................(20)6.3不同列重对LDPC码的影响......................................................................(21)6.4本章小结.....................................................................................................(22)结论...........................................................................................................................(22)参考文献...................................................................................................................(23)致谢...........................................................................................................................(24)淮南师范学院2012届本科毕业论文1基于MATLAB的LDPC码的仿真与研究摘要:随着无线通信技术的发展和各种传输方式对可靠性要求的不断提高，信道编码作为抗干扰技术的重要手段之一，在数字通信技术领域和数字传输领域显示出越来越重要的作用。目前3G和4G无线通信系统的信道编码的主流技术是Turbo码，其具有接近香农极限的优异性能，但是在码长较长的情况下，其误码性能还有待于提高。LDPC码是一种线性分组码，和Turbo码同属于复合码类。两者的性能相近，且两者的译码延迟都很长，其适用一些实时性要求不是很高的通信。但是在码长较长的情况下，LDPC码比Turbo码的译码性能更高而且在误码率上，在硬件应用和应用方面LDPC具有更大的优点。本课题主要研究LDPC码在不同条件下的误码率，译码算法和应用上相比其他编解码技术的优点，为B3G和4G无线通信系统的信道编码提供理论依据。本论文所做工作如下:本文阐述了LDPC码的基本原理和分析LDPC码关键技术及影响性能的因素;对LDPC码进行编码在MATLAB软件的环境下进行仿真，在仿真的图像上进行性能的分析;运用仿真的图像对LDPC和Turbo在误码率上进行分析比较;在研究LDPC码基本理论的基础上,利用MATLAB仿真比较不同码长、列重和迭代次数对LDPC码性能的影响，为B3G和4G移动通信提供了有利的参考价值。关键词：LDPC码；MATLAB；仿真ResearchandSimulationofLDPCcodeBasedonMATLABStudent:ChenchengTeacher:WangqianchunElectronicAndInformationEngineeringDepartmentOfHuainanNormalUniversityAbstract:Alongwiththewirelesscommunicationtechnologydevelopmentandallkindsoftransmissionwaytoimprovethereliabilityrequirements,channelcodingasoneoftheimportantmethodsanti-interferencetechnologyindigitalcommunicationtechnologyfieldanddigitaltransmissionfieldshowsthatmoreandmoreimportantrole.Current3Gand4Gwirelesscommunicationsystemof基于MATLAB的LDPC码的仿真与研究2channelcodingtechnologyisthemainstreamofTurboyards,ithastheclosetoshannon,theexcellentpropertiesofthelimit,butinyardslonglong,itserrorperformanceneedsimproving.LDPCcodeisalinearspace-timeblockcodes,andTurboyardswithbelongtothecompoundofcode.Bothsimilarperformance,andbothdecodingdelayareverylong,itissomerealtimerequirementofcommunicationisnotveryhigh.Butinthecodelengthislonger,LDPCcodethanTurbodecodingyardsintheberperformanceandhigher,applicationandapplicationinthehardwarehasmoreadvantagesofLDPC.ThistopicresearchLDPCcodeindifferentconditionsber,decodingalgorithmandapplicationcomparedwiththeotherdecodingtechnologyadvantages,forthreeG3Gand4Gwirelesscommunicationsystemprovidesthetheorybasisforthechannelcoding.Thispaperworkareasfollows:thispaperexpoundsthebasicprincipleandLDPCcodeanalysisLDPCcodekeytechnologyandinfluencefactorsofperformance;theLDPCcodeintheMATLABsoftwarecodeundertheenvironmentofthesimulation,thesimulationoftheimageintheperformanceanalysis;InthestudyofthebasictheoryofLDPCcode,basedontheuseofcomputersimulationcodelength,andallheavyanditeration.NumberofB3GLDPCcodeaffectperformanceand4Gmobilecommunicationprovidesfavorablereferencevalue.Keywords:LDPCcode；MATLA