一种改进的小波变换信号消噪方法

An Improved Signal Denoising Method Based on Wavelet Transform

根据小波阈值消噪方法的步骤及特点提出一种新的消噪方法——小波系数放大法,并对该方法进行仿真对比实验。该方法在运用小波变换对含噪信号进行消噪前,先对信号进行小波级数分解,对其中的低频系数和高频系数进行适当的放大,然后对信号采取阈值消噪法进行消噪,最后运用小波变换对所得到的小波系数进行适当的宿小,并将其重构。仿真实验结果表明,小波系数放大法消噪后信号的均方根误差有很大的降低,信噪比提高。该方法优于一般的消噪方法。

In this method, the coefficients including low and high frequencies of wavelet transform are magnified properly before denoised. The noises of coefficients magnified are removed by using the wavelet threshold. The coefficients denoised are minified aptly and reconstructed by the wavelet transform. In the simulation analysis, the average square root error of the coefficients denoised in this way dropped a lot,and the ratio of signal to noise increased. It is showed that the present method is better than other normal methods.