摘要：本设计通过在火车厢或地铁车厢里用手机录入一段车厢噪声，对其进行了时域分析，频谱分析,分析噪声信号的特性。并应用MATLAB进一步设计两种滤波器即Butterworth高通滤波器、低通滤波器，基于两种滤波器设计原理，用窗函数法设计出这两种滤波器，然后含噪的噪声信号进行滤波处理。23960
MATLAB语言是一种数据分析和处理功能十分强大的计算机应用软件，它可以将音频文件变换为离散的数据文件，然后利用其强大的矩阵运算能力处理数据，如数字滤波、傅里叶变换、时域和频域分析、声音回放以及各种频谱图的呈现等，它的信号处理与分析工具箱为语音信号分析提供了十分丰富的功能函数，利用这些功能函数可以快捷而又方便地完成语音信号的处理和分析以及信号的可视化，使人机交互更加便捷。信号处理是Mat lab重要应用的领域之一。
毕业论文关键字：  MATLAB；噪声信号；信号处理；傅里叶变换；滤波器
Rail Car Noise component analysis based on
Butterworth Filter
Abstract ： The design of mobile phone collection a noisy speech on the train or in the subway car , has carried on the analysis in time domain, frequency spectrum analysis, analysis of the characteristics of speech signal. And application of the MATLAB platform to the voice signal to remove noise, the further design of two kinds of filter is a high-pass filter, low-pass filter, based on the two kinds of filter design, window function method to design the three kinds of filter, and then with the original Rail car noise signal filtering.
  MATLAB language is a data analysis and processing functions are very powerful computer application software, sound files which can be transformed into discrete data files, then use its powerful ability to process the data matrix operations, such as digital filtering, Fourier transform, when domain and frequency domain analysis, sound playback and a variety of map rendering, and so on. Its signal processing and analysis toolkit for voice signal analysis provides a very rich feature function, use of these functions can be quick and convenient features complete voice signal processing and analysis and visualization of signals, makes computer interaction more convenient . MATLAB Signal Processing is one of the important areas of application.
Keywords:  MATLAB; Rail Car Noise Signal; Signal processing; FFT; Filter
 目 录
1.  绪论    1
1.1  课题的目的和意义    1
1.2  国内外研究现状与水平    1
1.2.1  语音合成    2
1.2.2  语音编码    3
1.2.3  语音识别    5
1.3  发展趋势    5
1.4  本文的主要工作及研究步骤    6
1.4.1  本文的主要工作    6
1.4.2  论文的研究步骤    6
2.  语音信号处理的基本知识    8
2.1  运行环境及系统    8
2.2  本文使用的软件Matlab介绍    8
2.2.1  编程环境    9
2.2.2  图形处理    10
2.2.3  程序接口    11
2.3  噪声语音的录入和打开    11
2.4  采样定理    12
    2.4.1  采样定理简介    12
    2.4.2  时域和频域采样定理    13
2.5  采样位数和采样频率    14
2.6  时域信号FFT分析    15
3.  对车厢噪声处理的基本要求和相关函数调用    17
3.1  设计的基本要求    17 基于Butterworth滤波的轨道交通车厢噪声成分分析+源程序:http://www.751com.cn/tongxin/lunwen_17245.html