Study of Basic Method about WSD Based on Chaos

In the present paper, duffing system is used to produce chaotic time series which is then used to reconstruct phase space, RCD algorithm is used to computer the largest Lyapunov characteristic exponent (LCE1), detailed program of these tasks successfully debugged in in Matlab 7.1 is given, experiment method is used to choose parameter in the program, LCE1 and dichotomy is used to find system parameter value which makes the system in critical chaos state, the relation between the LCE1 and the system parameter is also revealed by this method, the simulation results in Matlab 7.1 about the relation is analyzed and method of measuring amplitude of weak sine signal with LCE1 is proved feasible by the relation.