CHAOTIC SYNCHRONIZATION USING NONLINEAR ESTIMATORS WITH APPLICATION TO SECURE COMMUNICATION

摘要

This work is on performance comparison of three different nonlinear estimators in chaotic synchronization examples and their application to secure communications. Extended Kalman filter, Thau's observer, and high-gain observer techniques are used in state reconstruction of chaotic nonlinear systems. We show that synchronization of chaotic systems can be effectively achieved by using any of the above techniques. However, they exhibit different performances. A comparative robustness study involving performance under different measurement noise levels is also included. The above estimator methods are then applied to introduce a means to secure communications, by chaotic masking, where the information signal is injected into the chaotic signal in the transmitter where they are simultaneously transmitted to the receiver. The proposed methods are applied to Chua's chaotic circuit and the performances are compared based on Monte-Carlo simulations in order to demonstrate the relative effectiveness of estimator techniques.