基于小波变换的信号降噪和奇异性检测

Signal Denoising and Singularity Detection Based on Wavelet Transform

本文对基于小波阈值的信号降噪进行研究,重点讨论了阈值函数设计。传统的硬阈值函数法处理信号时,降噪后的结果有较大方差,软阈值函数法降噪后的结果相对平滑,但软阈值函数法降噪的同时削弱了小波系数的幅度,降噪结果会出现较大的偏差。基于此,本文提出了两种改进的阈值函数,用该两种函数对小波系数进行处理,降噪效果较为明显,信噪比得到较大的提高。

In this paper, the signal denoising method based on wavelet threshold is studied, and the threshold function design is discussed. The traditional hard threshold function method has a larger variance in de-noising results, and the soft threshold function method has smooth results, but the soft threshold function method also reduces the amplitude of the wavelet coefficients and the denosing result may appear a big deviation. Based on this, two improved threshold functions are proposed in this paper, and the denoising effects of the improved methods are obvious, and the SNR is greatly improved.