Unmasking chaotic mask by a wavelet multiscale decomposition algorithm

A method is proposed for extracting a useful signal hidden in a determinist ic chaotic signal using a wavelet multiscale decomposition algorithm that c an separate two signals with different wavelet scales. The mask removal is done without resorting to chaos synchronization. It is a noise reduction me thod without knowing the dynamical model of chaotic system, and restricting the modulation ratio of the chaos signal and useful signal. So this method is effective for unmasking chaotic mask through the quantitative analyses and the numerical simulations of three examples.