低信噪比信号的连续与离散小波变换比较研究

Comparative Study on Continuous and Discrete Wavelet Transform for Low Signal-to-noise Ratio Signal

详细介绍了离散小波变换与连续小波变换的发展历程及其基本原理,并对强背景噪声干扰下的碰摩信号分别采用这两种方法所达到的效果进行了研究和比较。发现在采用离散正交小波多分辨分析过程中,各层分解信号的非稳态特征几乎被噪声淹没,以致无法进行有效分析;而连续小波变换具有比离散小波变换更加细致的尺度空间,它在强噪声背景的干扰下,依然可以得到比较满意的分析效果。

The developing history and basic principle of discrete wavelet transform and continuous wavelet transform are introduced in detail. The effects reached by using these two methods on the rub-impact signals under interference of heavy background noise are compared. It is found that in discrete wavelet multiple resolution analysis, the unstable feature of the decomposed signal is fully drowned by noises; while in continuous wavelet transform, more detailed dimensional space can be obtained, and satisfactory analytic result still can be reached under heavy noisy interference background.