摘要数字信号处理应用在很多方面都在使用本文主要对信号进行处理，设计了低通滤波器。数字滤波器在数字信号处理中占有非常重要的地位，不能被替代。本文比较了数字滤波器和模拟滤波器，数字滤波器精度更高稳定性也要更强，系统函数发生变化容易，方便集成，使用起来很灵活，实现多维滤波相对简单一些。数字滤波器可以分为两种无限长冲击响应数字滤波器（IIR数字滤波器）和有限长冲激响应数字滤波器（FIR数字滤波器）。FIR数字滤波器有模拟滤波器不能比较的优势：就是稳定的系统，总能用因果系统来实现。72854

仿真使用的MATLAB软件包含了许多非常实用的功能比如计算、可视化、编程、仿真等等，操作使用方便简单，并且还拥有很强大的数值分析、矩形运算、绘制图形、处理数据等功能，本文使用的是M文件进行编程仿真。

设计FIR数字滤波器的三种主要办法可以利用窗函数、可以使用频率采样法也可以使用等波纹最佳逼近法。因为窗函数有闭合的公式可查找，所以为了实现滤波使用MATLAB采用窗函数设计FIR数字滤波器更加方便快捷。

该论文有图18幅，表3个，参考文献30篇。

毕业论文关键词：窗函数  MATLAB  数字滤波

Design and Simulation of Digital Filter Based on MATLAB

Abstract Digital signal processing technology has become a very important subject and application technology in the information age。 Digital signal processing applications in many aspects, including sound, voice, image, military, medical, household electrical appliances, etc。。 Digital filter in digital signal processing plays a very important role, can not be replaced。 It is more stable than the analog filter to be more stable and stronger, the system function is easy to integrate, easy to use, and to achieve a relatively simple multidimensional filter。 Digital filter can be pided into two kinds of digital filter (IIR digital filter) and finite impulse response digital filter (FIR digital filter)。 FIR digital filter has analog filter can not compare the advantage: the stability of the system, can always use causal system to achieve。

Matlab software is by design software developed by MathWorks company, contains many very practical functions such as computing, visualization, programming, simulation and so on, operation is simple and convenient to use, and also has very powerful numerical analysis, rectangular calculation, drawing, processing data and other functions。

Three main methods of designing FIR digital filters can be used to make use of window function and frequency sampling method。 Because the window function has a closed formula can be found, so in order to achieve the use of MATLAB filter window function to design FIR digital filter is more convenient and fast。

This paper has 18 figures, 3 tables, 30 references。

Key words: Window function  MATLAB  Digital filte 

目  录

摘  要 I

Abstract II

目  录 III

图清单 V

表清单 V

变量注释表 V

1 绪论 1

1。1 课题的研究背景和意义 1

1。2 滤波器的介绍和应用 2

1。3 论文组织结构 3

2 数字滤波器、模拟滤波器和MATLAB的介绍