Turbo码的编译码原理及仿真

四川师范大学成都学院本科毕业设计ITurbo码的编译码原理及仿真内容摘要：Turbo码是巧妙地将两个简单分量码通过伪随机交织器并行级联来构造具有伪随机特性的长码，并通过在两个输入/输出(SISO)译码器之间进行多次迭代实现了伪随机译码。目前Turbo码的大部分研究致力于在获得次优性能的情况下减小译码复杂度和时延，从而得到可实现的Turbo码系统。Turbo码具有极其广阔的应用前景，是信道编码界的一个重大突破，被称为二十一世纪的纠错编码。本文介绍了Turbo码的产生背景，研究意义，研究现状（编译码技术、Turbo码的设计和分析、Turbo码在CDMA系统中的研究及应用、面向分组的Turbo码、Turbo码与其它通信技术的结合），编码原理、译码原理及Turbo码的性能仿真及设计。通过对Turbo编译码原理的介绍及性能仿真的波形、频谱图的结果，本文对系统进行性能分析，并作了进一步的改进和调试。仿真结果证明了整个设计系统的正确性。由频谱特性可以看出：Turbo码不仅能够有效地抵御加性高斯噪声，而且具有很强的抗衰落和抗干扰特性。可以看出，Turbo码在现代通信中具有较大的优越性和重要作用。关键词：turbo码编码译码仿真四川师范大学成都学院本科毕业设计IITurboCodeprincipleAndSimulationAbstract:TheTurbocodeisingeniouslytwosimplecomponentcodebypseudorandominterleaverparallelcascadeconstructshasrandomcharacteristicoflongcode,andthroughthetwoinput/output(SISO)decoderbetweeniterationrealizedpseudorandomdecoding.Atpresent,mostofresearchdevotedtotheTurbocodeinobtainingsuboptimalperformanceintheabsenceofreducingdecodingcomplexityanddelay,thuscanrealizeTurbocodesystem.Turbocodehasextremelybroadapplicationprospect,isthechannelcodingcommunityamajorbreakthrough,knownasthetwenty-firstCenturyerrorcorrectioncoding.ThispaperintroducestheTurbocodegenerationbackground,researchsignificance,researchstatus(compiledcodetechnology,designofTurbocodeandTurbocodeanalysis,intheCDMAsystemresearchandapplication,apacket-orientedTurbocode,Turbocodeandothercommunicationstechnologies),encoding,decodingprincipleofprincipleandperformancesimulationofTurbocodesanddesign.BasedontheTurbocompilercodeprincipleintroductionandperformancesimulationwaveform,theresultofspectrum,thesystemperformanceanalysis,andmadeafurtherimprovementanddebugging.Thesimulationresultsprovethatthedesignschemeiscorrect.Thespectralcharactercansee:TurbocodecannotonlyeffectivelyagainsttheGaussnoise,butalsohasstrongresistancetofadingandinterferenceproperties.Ascanbeseen,theTurbocodeinmoderncommunicationhasmoreadvantagesandimportantrole.Keywords:theturbocodeencodingdecodingsimulation四川师范大学成都学院本科毕业设计III目录前言.............................................................................................................................................11绪论......................................................................................................................................21.1TURBO码的研究背景及发展..........................................................................................21.2本文的论文结构安排...................................................................................................42TURBO码的编码原理............................................................................................................52.1TURBO码的编码器的组成..............................................................................................52.2TURBO码的删余矩阵....................................................................................................62.3TURBO码的交织器..................................................................................................72.4本章小结..................................................................................................................93TURBO码的译码原理............................................................................................................93.1TURBO码的译码结构..............................................................................................93.2TURBO码的LOG-MAP算法............................................................................................113.3SOVA译码算法...........................................................................................................133.4各种译码算法的比较.................................................................................................143.5本章小结.....................................................................................................................154TURBO码的性能仿真及设计..............................................................................................154.1TURBO码仿真系统的实现............................................................................................154.2TURBO码的仿真结果及分析........................................................................................194.2.1不同码率对Turbo码的性能影响..................................................................194.2.2不同译码算法对Turbo码的性能影响.........................................................194.2.3迭代次数..........................................................................................................204.2.4交织长度..........................................................................................................214.3本章小结.....................................................................................................................225结束语.................................................................................................................................22参考文献...................................................................................................................................24四川师范大学成都学院本科毕业设计1Turbo码的编译码原理及仿真前言随着社会、经济的快速发展，Turbo码的应用越来越广泛。Turbo码是一类全新的纠错码，是一种新颖的信道编码方法，具有目前任何其它信道编码技术无法比拟的误比特性能。因Turbo码编码思想的新颖及其码性能的优越，自提出之日起就成为通信