文档介绍：Weizhong Chen: Study of Denoising Signals by Wavelet Transform under Labview ·1·
Study of Denoising Signals
by Wavelet Transform under Labview
Weizhong Chen
Department of Automation Science
School of Engineering and Technology
Shenzhen University
Abstract
This thesis analyzes, compares and discusses the respective applications on different kinds of
typical denoising processing methods. In addition, focusing on Wavelet Transform theory and the fast
algorithm of Mallat, we have carried out the Wavelet Transform using the building and calling method
of DLL functions under Labview. The hard threshold and soft threshold denoising methods are
introduced and implemented under Labview. Finally, an experiment has been made, and a new
denoising method by bination of wavelets and Fourier Transform (WFD) has been presented.
The results have showed that the new method is effective in processing the practical experiment
signals.
Key Words: Wavelet Transform, Mallat Algorithm, Denoising, Thresholding, Labview
教师点评:该毕业生计认真,内容新、全面、难度大。论文较系统地研究了传统基于傅里叶
分析和新的小波分析进行消噪的技术方法,提出了一种两者结合的新联合消噪方法,并进行了实
验验证,结果正确。特别可贵的是,全文采用英文撰写,条理清楚,写作流畅。表明:陈伟中同
学具有扎实的专业基础,高的英文水平和强的从事科研工作的能力,论文是一篇优秀的毕业设计。
(点评教师:曹广忠,教授)
1 Wavelets and Mallat Algorithm
Signal and information processing is one of the most rapidly developed subject in the field of
information science in recent ten years. Typical signal processing mechanisms, such as pure time
domain, pure frequency domain, short time Fourier Transform and so on have their own limitations. As
the result, their application extents are restricted. Wavelet Transform, which developed in late 1980’s, is
a new kind of time scale and time frequency analytic method. It has good localization characteristic in
both time and frequency domain. Nowadays, it is widely used in practical applications.
1-1 Multiresolution Analysis
brought the thought of Multiresolution Analysis of puter vision fiel