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I扩频通信中的伪随机码设计摘要扩频通信与常规通信系统相比，具有较强的抗人为干扰、窄带干扰和多径干扰能力，和信息隐藏以及多址保密通信等优点，因此在军事通信、移动通信等领域得到了广泛的应用。扩频通信的核心问题之一是扩频码的设计，即PN码的设计问题。随着扩频通信技术的发展，伪随机码在扩频通信中的作用越来越重要。本文主要介绍m序列、M序列、Gold序列及混沌序列的原理、构造方法及特性分析，并通过Matlab进行仿真来验证各个伪随机序列的随机特性，以期为以后的扩频通信中伪随机码的设计提供一些有意义的指导。关键词：计算机仿真;扩频;m序列;M序列;Gold序列;混沌序列IIThepseudo-randomcodedesigninSpreadSpectrumCommunicationsABSTRACTSpreadspectrumcommunicationhasmanyadvantagesovertheconventionalcommunicationsystemssuchasstronganti-humaninterference,narrow-bandinterference,multipathinterferencecapabilities,informationhiding,multipleaccessconfidentialcommunicationsandsoon.Soithasbeenwidelyappliedinmilitarycommunications,mobilecommunicationsandotherfields.OneofthecoreissuesinSpreadSpectrumCommunicationsisthedesignofSpreadingCodes.ThatisthedesigningproblemofPNcode.WiththedevelopmentofSpreadspectrumcommunicationtechnology,Pseudo-randomcodeplaysamoreandmoreimportantroleinSpreadspectrumcommunication.Thispaperpresentstheprinciples,structuresandcharacteranalyzingofmsequence,MSeries,Goldsequenceandchaoticsequence.Furthermore,randomcharacterofvariouspseudo-randomsequencesisverifiedbysimulationexperimentswithMatlabinordertoprovidesomemeaningfulguidanceforPseudo-randomcodedesigninSpreadSpectrumCommunications.Keywords:computersimulation;Spreadspectrum;m-sequence;M-sequence;Gold-sequence;haotic-sequenceIII目录1.绪论................................................................................................................................11.1研究的目的和意义..................................................................................................11.2国内外研究现状......................................................................................................11.3扩频的理论基础......................................................................................................21.3.1香农信道公式....................................................................................................21.3.2最佳相关接收....................................................................................................41.3.3伪随机序列的相关概念....................................................................................41.3.4伪随机序列的数学定义....................................................................................51.3.5伪随机序列的相关性........................................................................................61.3.6有限域的理论简介............................................................................................71.4本文主要研究内容................................................................................................102.常用伪随机码..............................................................................................................102.1m序列..................................................................................................................102.1.1m序列的定义...............................................................................................102.1.2m序列的性质................................................................................................112.1.3m序列的相关性............................................................................................112.1.4m序列的构造...............................................................................................122.1.5m序列的simulink仿真...............................................................................122.1.6m序列的相关性仿真...................................................................................142.2M序列的性质.....................................................................................................142.2.1M序列的仿真...............................................................................................162.3Gold序列.............................................................................................................172.3.1m序列优选对...............................................................................................182.3.2Gold序列产生的方法...................................................................................192.3.3Gold序列的相关特性...................................................................................202.3.4Gold序列的相关特性仿真...........................................................................212.3.5Gold序列的相关特性与m序列的相关特性比较仿真.............................222.3.6平衡Gold码..................................................................................................232.3.7平衡码的产生................................................................................................242.3.7.1特征相位...................................................................................................242.3.7.2相对相位...................................................................................................242.3.7.3平衡Gold码产生器的simulink仿真.....................................................263.混沌序列......................................................................................................................27IV3.1Logistic-Map的定义及所产生混沌的特性.......................................................283.1.2Logistic-Map混沌序列的仿真.....................