一类分数阶超混沌系统及其在扩频通信中的应用

提出了一类新的四维分数阶超混沌系统，对其动力学特性进行了理论分析和数值模拟。通过Lyapunov指数谱和分岔图分析了系统对阶次变化的敏感性。当微分阶次连续变化时，系统既存在混沌特性又存在周期特性。然后根据分数阶超混沌系统同步及扩频通信理论，提出了一个扩频通信方案。该方案使用混沌信号序列作为直接扩频通信系统的扩频地址码，用于替换传统的码分多址( CDMA)通信系统中的伪随机序列( PN序列)。最后，基于该分数阶超混沌系统设计一个扩频通信电路，在Multisim平台上验证了该方案的有效性和可行性。

A class of fractional-order hyperchaotic system and its application in spread spectrum communication

A class of fractional-order hyperchaotic system is introduced and its basic dynamical properties are investigated by means of theoretical analysis and numerical simulation. Systemic sensitivity to the orders of all involved derivatives is analyzed by stud-ying the Lyapunov exponent spectrum and bifurcation diagram. The class of fractional-order system presents hyperchaos, chaos, and periodic behaviors when the fractional orders vary continuously. Based on synchronization of the fractional-order hyperchaotic system and the theory of spread spectrum communication, we propose a new scheme for general spread spectrum communication. In contrast to PN code in the traditional CDMA communication, the scheme uses the chaotic signal sequence as a spread spectrum address code of direct sequence spread spectrum communication. Then, a circuit of spread spectrum communication based on the fractional-order hy-perchaotic system is designed. The validity and feasibility of this scheme are certificated in Multsim platform.