Application of Wavelet Packet Transform Layered Technique and Independent Sub-band Functions

In this paper, we discussed a new method of blind source separation of single mixed signal based on wavelet packet transform (WPT) layered technique and independent sub-band functions. Using WPT as a pre-processor, signal can be stratified into a number of narrow-band signals with equal length. After dealing with these narrow-band signals by ICA, we can get their independent sub-band functions, and a one-dimensional signal-aliasing can be expanded to a multi-dimensional signal. Then we can achieve the blind signal separation of single-aliasing. Through a system made by ourselves to detect the heart voice, we can study the changes of heart voice signal and provide services for the clinical diagnosis.