毕业论文--自适应噪声对消在语音信号处理中的应用研究

本科生毕业论文

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中文题目自适应噪声对消在语音信号处理中的应用研究

英文题目

摘要

在实际生活中，任何语音信号都不可避免的受到噪声信号的影响，如何有效的抑制和去除噪声，提高语音的可懂度是近年来的热门研究课题，文中介绍了自适应滤波器的基本原理，结构和应用，应用matlab软件，对自适应算法在噪声对消中的应用进行了仿真研究，并完成了语音信号噪声消除实例。

本文对自适应滤波算法在语音信号去噪方面进行了研究，对自适应对消系统进行了深入的学习与研究，在固定步长的基础上，建立了步长因子u与信噪比及噪声幅度之间的一种非线性函数关系，使步长随误差信号e(n)的变化而变化，从而提高了收敛速度，能够有效的滤除实际生活中语音信号中的高斯白噪声，工频干扰，以及其他讲话者的干扰，大幅度提高输出语音信号的信噪比，有效的提高语音的可懂度。通过实验证明，该算法在收敛速度，消噪性能，信噪比提高方面与常规的自适应算法相比均有一定的提高。

关键词：自适应滤波变步长LMS算法语音降噪

Adaptive noise cancellation in speech signal processing research

Abstract:

In our daily life ，all speech signal will be influenced by noise, How to effectively eliminate the noise is one of hot subjects for years.The paper begins with the principle of adaptive filter,structure and application. Based on the MATLAB platform, simulation is carried out for the applications of adaptive algorithms in noise cancelling，and completed the instance of voice signal noise reduction.

This paper discuss about adaptive filtering algorithm in the speech signal denoising aspects of the research on the adaptive cancellation system in-depth study and research and establishes another step factor u and the error signal e (n) between the non-linear function of a new relationship, the algorithm using variable step size, the step with the magnitude of the noise signal to noise ratio and the change, to improve the convergence rate, can effectively filter out in real life speech signal Gaussian white noise, frequency interference, and interference with other speakers. Can greatly enhance the output speech signal to noise ratio, experiments show that the algorithm convergence rate, noise reduction performance, improving signal to noise ratio with the conventional adaptive algorithms have improved to some extent compared. In this paper, the coefficient of the formula

fitting analysis, and find the optimal solution, the effect of noise correlation coefficient has done some analysis shows that the main channel of the input noise and the noise reference channel correlation coefficient higher learning , filter the better.

Key words:Adaptive Filtering; variable step size ; LMS algorithm ; Speech Enhancement

目录

1 绪论 (2)

1.1自适应噪声抵消技术研究背景 (2)

1.2语音降噪的发展及研究现状 (3)

1.3 本文的主要研究内容 (4)

2 自适应噪声对消原理概述 (6)

2.1自适应噪声抵消器原理 (7)

2.2 LMS自适应噪声抵消算法 (8)

2.3 LMS算法特点分析 (10)

2.4评价算法性能的指标 (13)

2.5 本章小结 (15)

3自适应噪声对消的模拟与仿真 (16)

3.1自适应噪声对消模型的建立及算法仿真 (16)

3.2 一种变步长LMS算法的提出与仿真 (22)

3.3 本章小结 (27)

4语音信号消噪实例 (28)

4.1信噪比的计算 (28)

4.2语音消噪实验 (29)

4.3 实验结果分析 (32)

4.4本章小结 (33)

总结与展望 (34)

参考文献 (35)