基于MATLAB的FIR数字滤波器设计.doc

摘 要 滤波器是用来选择所需的某种或某些频带的信号，而抑制不需要的其它频带信号的装置。滤波器作为信号处理的重要组成部分，已发展的相当成熟。滤波器可以分为两大类，即经典滤波器和现代滤波器。本文着重讲述了经典滤波器的MATLAB仿真。 数字滤波器是数字信号处理的重要环节，数字滤波器可以分为无限脉冲响应滤波器（IIR, Infinite Impulse Response）和有限脉冲响应滤波器（FIR，Finite Impulse Response）两大类。本文首先介绍了滤波器的滤波原理，重点介绍了IIR滤波器和FIR滤波器的基本设计原理，以及在MATLAB环境下如何将模拟滤波器转换为数字滤波器，并给出设计实例及运行结果。通过分析程序运行的结果得到模拟滤波器与数字滤波器的不同，以及IIR滤波器与FIR滤波器的不同之处，并与实际生产相联系得出他们各自的优缺点。 关键字：滤波 模拟滤波器 数字滤波器 MATLAB Abstract Filter is used to select a desired one or some frequency band signal, and suppresses the unwanted other band signal device. Filter for signal processing is an important component, has developed quite mature. The filter can be divided into two categories, namely, classical and modern filter filter. This paper focuses on the classic MATLAB filter simulation. Digital filter digital signal processing is the important link, digital filter can be divided into infinite impulse response filters ( IIR, Infinite Impulse Response ) and the finite impulse response filter ( FIR, Finite Impulse Response ) two categories. This paper first introduces the filter principles, introduced with emphasis on the IIR filter and a FIR filter design fundamentals, as well as in the MATLAB environment how to analog filter is converted to a digital filter, and gives examples of design and operation results. Through the analysis of the program running results are analog and digital filter is different, and the IIR filter and a FIR filter difference, and with actual production is linked to that of their respective advantages and disadvantages. Key words: filter AF DF MATLAB 目 录 1 绪 论 1 1.1 MATLAB软件简介 1 1.2 滤波器简介 2 1.2.1 滤波器工作原理 3 1.2.2 数字滤波器的设计方法 4 2 基于MATLAB的IIR数字滤波器设计 6 2.1 模拟滤波器的设计 6 2.1.1 巴特沃斯低通滤波器设计 7 2.1.2 切比雪夫低通滤波器设计 10 2.2 模拟-数字滤波器的转换 16 2.2.1 冲击响应不变法 16 2.2.2 双线性Z变换法 21 2.3 频带变换及其MATLAB实现 23 2.3.1 模拟低通滤波器转换成数字高通滤波器 24 2.3.2 模拟低通滤波器转换成数字带通滤波器 26 2.4 小结 30 3 基于MATLAB的FIR数字滤波器设计 31 3.1 常用窗函数及MATLAB实现 31 3.1.1 常用窗函数介绍 32 3.1.2 各种窗函数的比较与实现 34 3.2 基于窗函数的FIR数字滤波器设计 35 3.