基于MATLAB的数字滤波器设计 毕业论文.doc

基于matlab的数字滤波器设计 摘要：本文介绍的是数字滤波器在MATLAB环境下的设计方法。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。IIR数字滤波器的设计，我们需要借助模拟原型滤波器，然后再将模拟滤波器转化为数字滤波器，文中采用的设计方法是脉冲响应不变法、双向性变换法和完全函数设计法；对于FIR数字滤波器的设计，可以根据所给定的频率特性直接设计，文中采用的设计方法是窗函数法。根据IIR滤波器和FIR滤波器的特点，在MATLAB坏境下分别用双线性变换法设计IIR和用窗函数设计FIR数字滤波器，并采集的语音信号进行分析，最后给出了IIR和FIR对语音滤波的效果数字滤波器；IIR ；FIR ；MATLABThe Design of Digital Filter based on MATLAB Abstract：This article describes a digital filter in the MATLAB environment design. Digital filtering is an important part of digital signal processing which is playing a very big role in practice .The digital filter we studied can be divided into two categories——IIR and FIR. For the IIR digital filter design, we will need the help of simulation prototype filter, analog filters and then converted it into digital filter For the IIR digital filter design .The design methods used in the text is the same impulse response method, bi-sexual transformation and full function design ;We can based on the frequency characteristics of the given direct design, design method used in the text is the window function for FIR digital filter design. Based on the characteristics of IIR filter and FIR filters ,the bad paper in the MATLAB environment under the bilinear transformation method were used to design IIR and FIR with window function digital filter design and filters to capture both the voice signal analysis and compare. Through analysis of IIR and FIR Finally, the effect of filtering on the speech, and concluded the advantages and disadvantages in the two filter design methods in the MATLAB environment. Key words: Digital Filter ；IIR；FIR；MATLAB 目 录 1引言 1 2数字滤波器及MATLAB语言概述 2 2.1数字滤波器的定义和分类 2 2.2常用滤波器的性能指标 3 2.3 MATLAB概述 5 3IIR滤波器设计 8 3.1双线性变换法设计IIR数字滤波器 8 3.2脉冲响应不变法 12 3.3完全设计函数法 15 3.4语音滤波实例 16 4 FIR滤波器设计 21 4.1 窗函数法 21 4.1.1用窗函数设计FIR数字滤波器的基本方法 21 4.2 FIR滤波器滤波实例 26 5总结 31 ［参考文献］ 32 致谢 33 1引言 数字滤波在通信、图像编码、语音编码、雷达等许多领域中有着十分广泛的应用。目前，数字信号滤波器的设计图像处理、数据压缩等方面的应用取得了令人瞩目的进展和成就。是数字信号处理理论的一部分。数字信号处理主要是研究用数字或符号的序列来表示信号波形，并用数字的