-PAGE\*MERGEFORMAT66-重庆邮电大学本科毕业设计（论文）-PAGE\*MERGEFORMAT1-摘要在当今的数字信息的世界里，数字信号处理已经演变成一门越来越重要的学科，并在通信、语音、图像、自动控制、雷达、军事、航空航天、医疗和家用电器等众多领域得到了广泛的应用。其中数字滤波是数字信号处理的重要内容。数字滤波器可分为IIR和FIR两大类，对于IIR滤波器的设计来说主要有脉冲响应不变法和双线性变换法，而对于FIR数字滤波器的设计来说主要有窗函数法和频率采样设计法。本文应用MATLBA对数字低通滤波器进行仿真，并给出一定频率的信号通过所设计的滤波器来验证滤波器的性能，主要的研究工作主要包括以下几方面的内容:(1)介绍IIR滤波器和FIR滤波器的结构特点并比较两者之间的差别。(2)在MATLAB中应用双线性变换法和脉冲响应不变法设计IIR滤波器，给出了滤波器的频率特性图和相位特性图。(3)通过编写MATLAB程序用窗函数设计法和频率采样法来完成FIR低通滤波器的设计，并给出几个不同频率的信号通过所设定的滤波器来验证滤波器的性能。(4)在MATLAB中应用Simulink模块来仿真FIR低通滤波器，并在示波器上同时显示输入信号的频率和输出信号的频率，最后对结果进行分析。【关键字】FIR滤波器IIR滤波器,双线性变换法脉冲响应不变法窗函数法频率采样法MATLABABSTRACTInnowadaysworldofdigitalinformation,digitalsignalprocessinghasbecomeanincreasinglyimportantsubject,andhasbeenwidelyappliedinallfields,suchasmedicine,communications,andotherareas,digitalfiltersareimportantelementsofdigitalsignalprocessing.DigitalfilterscanbedividedintotwokindsofIIRandFIR,IIRfilterdesignforpulseresponsemethodandbilineartransformationmethod,forFIRdigitalfilterdesign,themainWindowsfunctionmethodandfrequencyofsamplingdesign.InthispapersimulationusingMATLABfordigitallow-passfilter,andtogiveasignalofacertainfrequencythroughthefiltersdesignedtoverifytheperformanceoffilter,themainresearchworkmainlyincludesthefollowingcontent:(1)DescribesthestructureofFIRandIIRfiltersfiltercharacteristicsandcomparisonofthedifferencesbetweenthetwo.(2)InMATLABusingbilineartransformationmethodandimpulseresponsemethoddesignofIIRfilters,tooutofthefiltersoffrequencyresponseandphasecharacteristics.(3)DesignmethodbywritingMATLABprogramsusethewindowsfunctionandfrequencysamplingmethodtoaccomplishthedesignofFIRlow-passfilters,andgivesseveraldifferentfrequencysignalspassesthroughasetoffilterstoverifythatthefilter'sperformance.(4)IntheMATLABSimulinksimulationFIRlow-passfiltermoduletotheapplication,andalsoonthescopedisplaysthefrequencyoftheinputsignalandtheoutputsignalfrequency,finalanalysisoftheresults.【Keywords】FIRdigitalIIRdigitalfilterBilineartrans