改进的小波域阈值去噪方法

针对使用常规小波域阅值去噪方法对含有高频噪声的低频信号或较平稳信号进行处理时，其去噪效果和信号保真度有时不能令人满意的问题，提出了一种对小波变换尺度1上的小波系数进行二次小波变换，并进行去噪处理后重构小波系数的新方法。该方法可去除大部分高频随机噪声。此后，再对重构后的信号进行小波域阈值去噪处理。仿真结果表明：该方法去噪效果明显，且信号主要细节保留较好。

A modified de-noising method by threshold filter in wavelet domain

Using conventional de-noising method by threshold filter in wavelet domain can remove random noises, but its de-noising effect and signal fidelity is not always good. A new modified method of removing random noises is proposed in this paper, which combines quadratic wavelet transform and threshold filter. The simulation result shows that the new method is not only able to remove the strong noises effectively, but also can hold the main details well.