基于MATLAB的有噪声语音信号处理_毕业设计

本科毕业设计论文

基于MATLAB的有噪声语音信号处理

摘要

滤波器设计在数字信号处理中占有极其重要的地位，FIR数字滤波器和IIR 滤波器是滤波器设计的重要组成部分。Matlab功能强大、简单易学、编程效率高,深受广大科技工作者的欢迎。特别是Matlab还具有信号分析工具箱,不需具备很强的编程能力,就可以很方便地进行信号分析、处理和设计。利用MATLAB 信号处理工具箱可以快速有效地设计各种数字滤波器。课题基于MATLAB有噪音语音信号处理的设计与实现，综合运用数字信号处理的理论知识对加噪声语音信号进行时域、频域分析和滤波。通过理论推导得出相应结论，再利用MATLAB 作为编程工具进行计算机实现。在设计实现的过程中，使用窗函数法来设计FIR 数字滤波器，用巴特沃斯、切比雪夫和双线性变法设计IIR数字滤波器，并利用MATLAB作为辅助工具完成设计中的计算与图形的绘制。通过对对所设计滤波器的仿真和频率特性分析，可知利用MATLAB信号处理工具箱可以有效快捷地设计FIR和IIR数字滤波器，过程简单方便，结果的各项性能指标均达到指定要求。

关键词数字滤波器；MATLAB；窗函数法；巴特沃斯；切比雪夫；双线性变换

Abstract

Filter design in digital signal processing plays an extremely important role, FIR digital filters and IIR filter is an important part of filter design. Matlab is powerful, easy to learn, programming efficiency, which was welcomed by the majority of scientists. Matlab also has a particular signal analysis toolbox, it need not have strong programming skills can be easily signal analysis, processing and design. Using MATLAB Signal Processing Toolbox can quickly and efficiently design a variety of digital filters. MATLAB based on the noise issue speech signal processing design and implementation of digital signal processing integrated use of the theoretical knowledge of the speech signal plus noise, time domain, frequency domain analysis and filtering. The corresponding results obtained through theoretical derivation, and then use MATLAB as a programming tool for computer implementation.Implemented in the design process, using the window function method to design FIR digital filters with Butterworth, Chebyshev and bilinear Reform IIR digital filter design and use of MATLAB as a supplementary tool to complete the calculation and graphic design Drawing. Through the simulation of the designed filter and the frequency analysis shows that using Matlab Signal Processing Toolbox can quickly and easily design digital filters FIR and IIR, the process is simple and convenient, the results of the performance indicators to meet the specified requirements.

Keywords：digital filter; MATLAB; Chebyshev; Butterworth;Window function method; bilinear transformation

目录

1．绪论 (1)

1.1研究的目的和意义 (2)

1.2 国内同行研究现状 (2)

1.3本课题的研究内容 (4)

2.原始语音信号采集与处理 (5)

2.1 Matlab简单介绍 (5)

2.2 语音信号的采样理论依据 (6)

2.3语音信号的采集 (7)

2.4程序流程图 (7)

2.5语音信号的时频分析 (8)

2.6 语音信号加噪与频谱分析 (9)

2.7 本章小结 (11)

3设计数字滤波器 (12)

3.1 数字滤波器设计的基本思路 (12)

3.2 模拟滤波器概述 (12)

3.3 IIR数字滤波器概述 (12)

3.4 FIR数字滤波器概述 (13)

3.5 FIR数字滤波器和IIR数字滤波器比较 (13)

3.6 低通，高通及带通滤波器 (14)

3.7 设计FIR滤波器 (14)

3.8 设计IIR滤波器 (15)

3.9 双线性变换法和窗函数法 (15)

3.10 本章小结 (18)

4 进行滤波，比较滤波前后语音信号的波形及频谱 (19)

4.1验证所设计的滤波器 (19)

4.2滤波 (21)

4.3本章小结 (23)

5.GUI界面 (24)

5.1系统界面设计工具—GUI概述 (24)

5.2创建GUI界面 (24)

5.3创建开关按钮 (25)

5.4保存和修改fig文件 (26)

5.5编写M文件 (28)

5.6本章小结 (33)

总结 (34)