Design And Research Of The Discrete Chaotic Communication System

As a phenomenon found in non-lineear system, chaos is deterministic and random-like process.The chaotic system is highly sensitive to their initial conditions, so it can generate a large number of contiuous broadband frequency spectrum, non-periodic, noise-like, yet deterministic and reproducible signals, which is very useful for secure communications. Based on applications of chaotic technolcgy to contemporary secure communications, the author has performed comprehensive research and obtained the following innovative results:1. The character of the chaotic system is summed up. This paper summarise the development history of chaos, and it is an emphases of discussing about the Lyapunov exponent and the chaos attractor which is a great deal used in this paper.2. it is an emphases about several kinds of the advantage and disadvantage and the development forceground of the chaotic communication.3. Constuction of a chaotic communication system based on the Logistic inverse map of variable parameter: the analysis of Lyapunov exponent to the Logistic inverse map indicates it presents the chaotic performance in the relatively wider parameter range, so we make use of this character to constucte a chaotic shifting parameter communication system based on the Logistic inverse map . At the same time, there is a performance improvement about communication security , the validity, the dependability and the feasibility of chaotic inverse map communication system using negative transform and voltage movement, and the simulation proves the feasibility and advantage of the system. The application of the discrete chaos system accords with the current of the digital communication times. In addition, the aim of the research make the chaotic communicatiaon in a laboratory phase intoeffect as quickly as possible.4. Constuction of a chaotic communication system based on mixing several chaotic maps and shifting parameter : This paper construct a chaotic mixed map using Logistic map and cube map, and the analysis of Lyapunov exponent indicates that this kind of map presents the chaos character. At the same time, this paper constructs a chaotic communication system of shifting parameter based on the chaotic nixed map that give birth to chaotic carrier wave signals, and the security of information transmitted is improved by means of time-sharing shifting parameter , which solves the problem that the chaotic sequence present periodicity because of the limited precision. Otherwise, the noise of signals is alse de-nised by the wavelet filters.5. de-noising based on the wavelet theory:this paper use the wavelet filters to reduce the added noise of signals , and the performance of resisting noise is promoted.the wavelet analysis is a way of the topical time and frequence analysis that changes the time and frequence windows, and a way of the multiresolutio analysis to the non- smooth signals.