The Chaos Communication Based On Register And Noise Analysis

In this paper, we added register to the chaotic secret communication scheme, and through the corresponding numerical simulation to analyze the validity of this method, the author's main job is follow:1) we have proposed a new method which realizes secure communication by using register, synchronization and chaotic shift keying. In the sending-end, encrypt useful signals by choosing different encrypted functions through the controlled signals. Then store the controlled signals into the register, and brings them out after they reach a certain length to make up a new sequence with encrypted useful signals. At last, launch them after they are modulated by chaos system which is chose by keying technology. In the receiving-end, restore the receiving signals after demodulation by comparative distinguish first. Separate the useful signal from the controlling signal afterwards. And decode to restore useful signal effectively thereby. This program enhances the complexity of the sending signals, at the same time, it realizes the safe and secret translation of signals. Simulation result indicates the availability of this program.2) We have proposed a new method which based on chaotic modulation and chaos shift keying. At the sending end, we separate the useful signals into two group of related signal sequence accord to a centain rules(such as separate and combine the signals by their parity position). Then put this two group signals into different systems, chaotic modulation system and chaos shift keying system, which can modulate them, and transmitted them alone; And at the receive end, we have to demodulate the received signals individual, so we can obtain the original transport signals. At the end, by the predetermined protocol according to the sending end, we combined the two group signals into one complete sequence. Simulation result indicates that wan can recover the signals correctly on the chaos sychronization's occasion, and this scheme have strong feasibility and validity.3) We investigate the possibility to improve the noise performance of a chaotic digital communication scheme by utilizing further dynamical information. First, at the sending end, We show that by encoding the initial information of the chaotic carrier according to the transmitting bits, extra redundance can be introduced into the segments of chaotic signals corresponding to the consecutive bits. Such redundant information can be exploited effectively at the receiver end to improve the noise performance of the system. Furthermore, the Viterbi algorithm can be applied before the demodulation step to overcome the performance degradation in the high SNR region. The study indicates that it is possible to improve the noise performance of the chaotic digital communication scheme if further dynamics information is added to the system.