Research On Digital Secure Communication Of Hyperchaotic Synchronization

Chaos is a quasi-stochastic phenomenon appearing possibly in definite nonlinear dynamic systems. Chotic motion is a complex nonlinear motion and the chaotic phenomenon has been observed in a lot of real systems.The dynamic properties of chaos signal such as ergodicity, aperiodic, uncorrelated, broadband and noise-like have been proved to be useful for secure communication. The chaotic synchronization is the theory basis of secure communication.The research of the chaotic synchronization and its application becomes a new research focus in nonlinear science fields.The main content of this paper contains the analysis of hyperchaotic synchronization and application of hyperchaotic secure communication. In this dissertation, the main contributions are as follows:Firstly, the application of chaotic synchronization and its current situation is described systematiclly, then three chaotic synchronization schemes are designed with three different methods, which are the drive-response chaotic synchronization, the synchronization method based on feedback and the observer-based synchronization method. Then make numerical simulations with the three schemes, from the results, we can see that the observer-based chaotic synchronization method has more advantages than the others. Hyperchaotic systems have the features with which can make them more suitable for digital secure communications, then, a method based on state observer hyperchaotic program is designed and verified by numerical simulation of the correctness and chaotic synchronization effectiveness.Secondly, three chaotic synchronization methods used for secure communication are in depth study, namely, chaotic masking, chaotic parameter modulation, chaotic shift keying and chaotic spread-spectrum theoretical analysis. A state observer based on chaotic masking method program is designed, through numerical simulation, the effectiveness of the program is demonstrated. Because the traditional chaotic masking technology has some shortcomings, a hyperchaotic observer-based synchronization secure communication scheme is designed, from theoretical analysis and numerical simulation results, we can get that it is an effective secure communication scheme, and has higher confidentiality.