基于MATLAB的数字滤波器设计_毕业论文.doc

基于MATLAB的数字滤波器的设计 摘 要 本文分别研究了在MATLAB环境下IIR数字滤波器和FIR数字滤波器的设计方法及实现方法，并进行图形用户界面设计，以显示本文所介绍滤波器的特性。 在无限脉冲响应（IIR）数字滤波器设计中，先进行模拟滤波器的设计，然后进行模拟-数字滤波器转换，即采用脉冲响应不变法及双线性Z变化法设计数字滤波器，最后进行滤波器的频带转换。在有限脉冲响应（FIR）数字滤波器设计中，讨论了FIR线性相位滤波器的特点和用窗函数法设计FIR滤波器两个问题。两类滤波器整个设计过程都是按照理论分析、编程设计、具体实现的步骤进行的。 为方便分析者直观，形象，方便的分析滤波器的特性，创新的设计出了图形用户界面——滤波器分析系统。整个系统分为两个界面，其内容主要包含四部分：System(系统)、Analysis(分析)、Tool(工具)、Help(帮助)。 关键词：数字滤波器、MATLAB、无限脉冲响应、有限脉冲响应、图形用户界面 Matlab-based digital filter design Abstract In this thesis, designs of the Infinite Impulse Response digital filter (IIR) and Finite Impulse Response digital filter (FIR) under MATLAB are studied. And the Graphical User Interfaces (GUI) to analysis the characteristics of filter is designed. The design of IIR filters can be achieved through three steps: firstly, the design of analog low-pass filter; secondly, it is analog-to-digital filter conversion; lastly, it is the conversion of filter frequency band. In design of FIR filters, two questions are discussed: the characteristics of FIR linear phase filter and reasoning of related formulas; the other is about the design of the FIR filters by means of window functions. The design of FIR and IIR follows the procedures of theoretical analysis, programming design and realization. We design the Graphical User Interfaces (GUI) of the digital filter analysis system makes sure of people can analysis the characteristics of the design directly and easily. The whole system divide into two graphical interfaces, it contains four parts: System, Analysis, Tool and Help. Keywords: Digital Filter, MATLAB, IIR, FIR, Graphical User Interfaces 目 录 引言……………………………………………………………………………………… 1 第1章 绪论………………………………………………………………………………2 1.1 数字滤波技术………………………………………………………………………2 1.1.1 滤波器原理………………………………………………………………………3 1.1.2 数字滤波器设计方法概述………………………………………………………3 1.2 MATLAB软件简介……………………………………………………………………4 第2章 IIR滤波器概况及其MATLAB实现…………………………………………6 2.1 模拟滤波器及其MATLAB实现…………………………………………………6 2.1.1 巴特沃斯低通滤波器………………………………………………………6 2.1.2 切比雪夫低通滤波器