Exponential Synchronization Of Delayed Chaotic Systems And Its Application In Secure Communication

As the particular movement of the nonlinear dynamic systems, chaos is one of the most important discoveries in 20th century. Chaotic signal possesses the properties of ergodicity, continuous broadband power spectra, and noise like etc. These features make it naturally suitable for secure communication as a carrier. In the past 20 decades, with the deeper understanding of chaotic phenomena, chaotic control and synchronization have become an important issue, which were also used in secure communication.In this thesis, the synchronization of a class of delayed chaos and its application in secret communication are studied deeply through theoretical analysis and numerical simulations. The main achievements include:â‘ Survey and prospect of chaos synchronization are summarized, and then we analyze several existing synchronization methods such as Drive-Response synchronization, Impulsive synchronization, Coupling synchronization as well as Adaptive Synchronization.â‘¡The exponential synchronization of delayed chaotic systems is studied based of Lyapunov stability theory and differential inequality. A sufficient condition of exponential synchronization is then given by using the linear matrix inequality. The numerical simulations are also presented to demonstrate the effectiveness of the theoretical results.â‘¢We analyze theoretically several main schemes for chaotic secure communication including chaotic masking, chaos modulation and chaotic switching, and point out the existing problems of these schemes. Based on the exponential synchronization of a class of delayed chaotic systems, we design a modified communication scheme by using chaotic masking technique. The robustness of the proposed scheme is also analyzed. Numerical results indicate that our scheme is effective.