Chaos Synchronization And Its Application In Secure Communication

Based on the theory of nonlinear control and stability analysis, this dissertation studies the chaotic characters and the ways of designing synchronization. Then we apply synchronized systems in secure communication.In the part of synchronization, we firstly study the PC method and the feedback method. Based on them, a mixed approach of chaos synchronization is gained which not only shortens the time to achieve the synchronization but also improves the performance of noise reduction; Then, in order to achieve the adaptive synchronization for unified chaotic systems with different parameters, we design an appropriate parametric control and feedback control; Lastly, we study the synchronization of hyper-chaotic system, mainly using the state observers to achieve total and generalize synchronization.We mainly study three methods in this part of secure communication. It includes the chaos masking, parameter.modulation and chaos modulation. Based on the chaos masking, a multistage synchronized system for secure communication is proposed, which improves greatly the secure property and practicability; Then, we modulate the formal parameter-modulated system. In the receiver, the information is demodulated by analyzing synchronization error . This improves the performance of noise reduction; Lastly, we study the synchronization in cellular neural network, and present a secure communication based on hyper-chaos. It is more secure because of the hyper-chaotic system and encryption techniques of the hyper-chaotic with several states of the super-chaos system.