信号的采样及频率混叠现象分析

信号的采样及频率混叠现象分析信号的采样及频率混叠现象分析摘要伴随着计算机技术的发展和广泛应用，信号分析与处理理论作为一门新兴学科，正受到越来越多的关注。测试信号采样分析是信号分析的重要内容之一，它具有复杂性和抽象性。本文详细介绍了信号方面的相关知识，以及基于Matlab进行信号采样及频率混叠现象分析的方法。本设计采用Matlab软件为主要工具，对信号的采样及采样后引起的频率混叠现象进行分析。在对信号进行采样分析时，通过改变采样率，观察信号时域采样和频域采样的变化，从而进一步分析，由于采样率不足而引起的频率混叠现象。最后提出避免混叠现象产生的有效措施。关键字：带限信号;时域采样;频域采样;频率混叠现象信号的采样及频率混叠现象分析AAAANALYSISNALYSISNALYSISNALYSISOFOFOFOFSIGNALSIGNALSIGNALSIGNALSAMPLINGSAMPLINGSAMPLINGSAMPLINGANDANDANDANDFREQUENCYFREQUENCYFREQUENCYFREQUENCYALIASINGALIASINGALIASINGALIASINGPHENOMENONPHENOMENONPHENOMENONPHENOMENONAbstractAbstractAbstractAbstractWiththedevelopmentandextensiveapplicationofcomputertechnology,Signalanalysisandprocessingtheoryismoreandmorebeingattentionasanewsubject.Analysisingoftestsignalsamplingisanimportantpartofsignalanalysis,whichiscomplexandabstract.ItisdescribedrelevantknowledgeofthesignalsamplingandillustratedtheMatlab-basedMethodsofsignalsamplingandaliasinginthepaper.ItisusedMatlabsoftwareasthemaintoolinthedesign,andanalysisingofsignalsamplingandaliasingphenomenon.Wecanobservethechangeofsignalintimedomainsamplingandfrequencydomainsamplingbychangingthesamplingrateinthesamplinganalysis,furtheranalysis,duetoinsufficientsamplingratecausefrequencyaliasing.Finally,itisputforwardeffectivemeasuresavoidingthealiasingphenomenon.KeyKeyKeyKeywordswordswordswords:Band-limitedsign;Timedomainsamplin;Frequencysampling;Frequencyaliasingphenomenon信号的采样及频率混叠现象分析目录1绪论...............................................................................................................................................11.1课题背景及目的...............................................................................................................11.2国内外研究现状...............................................................................................................21.3课题研究方法...................................................................................................................31.4论文构成及研究内容.......................................................................................................42Matlab的使用方法....................................................................................................................52.1Matlab简介.....................................................................................................................52.2Matlab快速入门.............................................................................................................62.2.1Matlab的操作界面.............................................................................................62.2.2Matlab常用函数.................................................................................................72.2.3Matlab的帮助系统.............................................................................................73测试信号的时域采样.................................................................................................................93.1信号的时域采样...............................................................................................................93.2频率混叠现象................................................................................................................113.3时域采样定理.................................................................................................................123.4实例仿真分析.................................................................................................................124测试信号频域采样...................................................................................................................284.1信号频域采样................................................................................................................284.2频域采样定理................................................................................................................284.3实例仿真分析................................................................................................................295信号的频率混叠现象...............................................................................................................325.1频率混叠........................................................................................................................325.2频率混叠现象的原理....................................................................................................325.2.1频域和时域的对应关系....................................................................................325.2.2频率混叠现象的原理........................................................................................32信号的采样及频率混叠现象分析5.3混叠频率与真实频率的关系.......................................................................................335.4频率混叠现象的处理措施...........................................................................................345.4.1FFT参数的选择.................................................................................................345.4.2抗混叠滤波器.....................................................................................................375.5实例仿真分析.............................................................................................................