Research On Chaotic Signal Generator And Its Performance Analysis

Chaos is a kind of complicated oscillation, which is produced by definite system and described by nonlinear equation. It lies between cycle oscillation and noise. Because of the sensitive initial value and wide spectrum, chaotic application in the field of secure communication and spread spectrum communication has already attracted people's eyes. So, it is vital to study and develop new chaotic signal generator and push Chaos theory to good use. Nowadays, there are two kinds of implementation methods of chaotic signal generator. One kind is realized by analog line and it is very sensitive to circuit inherent parameters as well as signal recycled error, so it is relatively difficult to realize actually, the other kind is realized by digital line and it can generate well real-time discrete array, so it is more suitable for the application in communication.Based on the research results of Chaos theory, in this dissertation, it has made detailed analysis of the chaotic signal generator. Firstly, the characteristic and various detection methods of chaotic signal are recommended. Secondly, with the aid of software, such as MATLAB, PSPICE, EWB, etc, discussion of the process of generating chaotic signal proceeds. Through simulation, the output result of several kinds of chaotic circuit are analyzed and compared. Thirdly, aiming at Chua's chaotic circuit, through debugging, the impacts by components and parts in the circuit, such as operation amplifier, capacity, inductor, etc, has been further investigated. And then provides a new scheme to implement Lorenz chaotic system, the circuit design and analysis are presented in detail and it can be realized by the hardware of programmable arrays FPGA, the experimental results indicate that this scheme has the advantages of easy operation, flexible design and high efficiency. An application example in secure communications is also provided. Finally, through picking up the characteristic parameter-Lyapunov exponent of the Chaos we can analyze the performance of different chaotic signal generators.