Several Sychronization Of Chaotic Systems And Their Secure Communication Research

Chaos theory is an important branch of nonlinear science, which reveals the universal complexity existing in the nature and human being world and builds a bridge between determine theory and probability theory. Chaos can be used in wildly fields, so over the last decade years, chaos synchronization technology has attracted more and more scholars to research, especially in secure communication field. This paper combines theoretical derivation and numerical simulation method to research some kinds of typical chaos synchronization problems and its application in secure communication. The main tasks are as follows.Firstly, the paper simply introduces the chaotic development history, and then describes the general synchronization methods, finally explains the significance of chaos secure communication.Secondly, this paper deals with the finite-time chaos synchronization of a new hyperchaotic Lorenz system. Based on the finite-time and Lyapunov stability theory, a simple and robust controller is proposed to realize finite-time chaos synchronization for the hyperchaotic Lorenz system. Theoretical analysis proved that the scheme can ensure the error system globally finite-time stable. Numerical simulations are provided to show the effectiveness of the proposed schemes.Thirdly, based on the nonlinear state observer algorithm and pole placement technique, a synchronization scheme is designed. The projective synchronization of a class of delayed neural networks can be achieved by using the proposed method, and they are proved theoretically. Numerical simulations of delayed Hopfield network and three order cellular neural networks are provided to further demonstrate the effectiveness of the proposed scheme. Moreover, this paper proposes and creates a new full state hybrid projective synchronization and provides the theoretical proof, which enlarges the applied scope of full state hybrid projective synchronization. Take unified chaotic system and hyper-chaotic Rossler system for example, after numerical simulations, further validates the effectiveness of the proposed scheme.Finally, this paper presents a new secondary chaotic secure communication system for analog signal transmissions. It contains four important parts: chaos synchronization, chaotic modulation, chaotic mask, and chaotic receiver. Based on the theory of state observer, a method of chaos synchronization is presented, and it is applied to the secondary secure communication system. Some simulation results are provided to verify the efficiency of the proposed secure communication system.