先对信号进行两层分解，构造小波分解结构[c,l] 然后使用函数wnoiset()获取噪声方差，接着使用函数wbmpen()获取小波去噪阈值，最后使用函数wdencmp()实现信号去噪。-The first two layers of the signal decomposition, construct wavelet decomposition structure [c, l]　then use the function wnoiset () to get the noise variance, and then use the function wbmpen () to get the wavelet threshold de-noising, last used function wdencmp () signal denoising .