Introduction - If you have any usage issues, please Google them yourself
In the process of wavelet decomposition, every wavelet decomposition to get the approximate signals will be more smooth than on a level of signal, and inhibited detail coefficients exist in each layer. So a noise signal can be 5 layers of decomposition, and selectively inhibit some detail coefficients can achieve the goal of signal noise reduction. Trials of the signal by db3 wavelet decomposition.