基于MATLAB的频谱分析和信号去噪.doc

本科毕业论文(设计)


题目基于MATLAB的频谱分析和信号去噪
指导教师

学生姓名学号
专业电子信息工程班级
院(系) 电子信息工程学院
完成时间 2011年4月13日
基于MATLAB的频谱分析和信号去噪
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。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 MATLAB/滤波器/频域分析/滤波
Based on the MATLAB spectrum analysis and signal denoising
ABSTRACT
Filter design in digital signal processing in occupies an extremely important status, FIR digital filters and filter IIR filter is the ponent. MATLAB signal processing toolbox can effectively design of digital filter. Subject have noise based on MATLAB speech signal processing, the design and implementation of integrated use of digital signal processing theory knowledge of speech signal with noise adding time domain and frequency domain analysis and filtering. Through theoretical derivation corresponding conclusion as a programming tool, using MATLAB puter implementation. In the design and implementation of process, USES window function method to design FIR digital filters, with bart leavenworth, chebyshev and bilinear anshi IIR digital filter, and design MATLAB as the auxiliary plete design puting and graphics drawing. Through the design of the filter selvesor simulation and frequency characteristics were analyzed, using MATLAB signal processing toolbox that can effectively quickly design FIR and IIR digital filters, process is simple and convenient, results of various performance indicators are as specified requirements.
KEY WORDS MATLAB, filter, frequency domain analysis, filtering
目录
摘要 I
ABSTRACT II
1 绪论 1
2 基于滤波器的语音信号的处理 2
语音信号的采集 2
设计FIR和IIR数字滤波器 2
用滤波器对加噪语音信号进行滤波 6
3 仿真及其结果分析 7
语音信号的时频分析 7
加噪后的语音信号及其频谱分析 8
通过滤波器处理的加噪语音信号的分析 9
IIR与FIR滤波器处理结果的的比较分析 1