摘要

To further improve the performance of blind extraction of harmonic signals under the chaotic background, an algorithm based on the steady-state point capture was proposed. Since energy distribution of the chaotic signal has an important influence on the extraction accuracy, when the frequency of harmonic signals drop in the energy focused region of the chaotic signals, the data after the chaotic signal meet the steady-state point is capable of significantly improving the extraction precision. The solution to capturing steady-state point of typical chaotic system was obtained by solving the Lyapunov exponent. Furthermore, the influence of the frequency interval between harmonic signals was analysed. An empirical constant value of frequency interval to ensure the effective extraction was also derived by a large number of simulation experiments. Simulation results show the effectiveness of the proposed method, and the method provides an effective means to verify the security of chaotic secure communication system.