一个时延混沌系统的耦合同步及其在保密通信中的应用

近年来，混沌同步成为一个研究热点，特别是它在保密通信中的潜在应用。系统地研究了一个时延混沌神经元系统的耦合同步问题。基于Krasovskii-Lyapunov理论，分析了同步的渐近稳定性，给出并证明了判定同步的一个充分条件，并对耦合强度阈值进行了估计。计算机数值仿真结果表明，该耦合系统具有良好的同步效果和鲁棒性，证实了仿真结果与理论分析是相符的。最后基于混沌掩码技术给出了在扩展频谱保密通信中的一个应用实例。该应用系统的特点是只需传送一个标量信号就可实现同步，由于该信号直接驱动接收系统，且具有类似噪声的宽频谱特性，因此难以预测和破译，提高了通信系统的保密性能。

Synchronization of a Coupled Time-Delay Chaotic System and Its Application to Secure Communications

In recent years, chaotic synchronization has become an area of active research, especially in light of its potential application to secure communications In this paper, the synchronization of a coupled delayed neuron chaotic system is investigated The asymptotic stability of the synchronization is analyzed based on the Krasovskii Lyapunov theory, and a sufficient condition of synchronization is obtained Furthermore, the synchronization threshold of the coupled system is estimated The results of computer numerical simulation show that the proposed synchronization system is an effective one, which is robust when Gaussian white noise N (0,0 0005) is added, and the simulation result is consistent with the theory analysis Finally, an application example is given, which uses the proposed chaotic system to realize spread spectrum secure communications based on the chaotic masking strategy The advantage of this application system is that synchronization can be achieved by transmitting just a single scalar variable Because this scalar variable is used to directly drive a receiver, and possesses broadband power spectra property, so this makes it difficult to detect or predict the signal in either the time or frequency domain, and the communication system is more secure consequently