基于元胞自动机的耦合映像格混沌扩频通信  

Chaotic Spread Spectrum Communication with Coupled Map Lattice Based on Cellular Automata

作　　者：马英杰 罗瑆玥 赵耿 杨亚涛 曾萍 MA Yingjie;LUO Xingyue;ZHAO Geng;YANG Yatao;ZENG Ping(Department of Electronic and Communication Engineering,Beijing Electronic Science and Technology Institute,Beijing 100070,China)

机构地区：[1]北京电子科技学院电子与通信工程系,北京100070

出　　处：《北京邮电大学学报》2023年第6期72-76,114,共6页Journal of Beijing University of Posts and Telecommunications

摘　　要：为解决混沌系统的输出分布不均匀以及在有限精度下混沌系统动力学退化的问题,基于初等元胞自动机迭代规则和耦合映像格系统,提出了伪随机耦合映像格混沌扩频码生成算法。首先,利用初等元胞自动机控制耦合映像格系统中每个格子的耦合对象,迭代初值由不同初等元胞自动机迭代规则的异或运算生成,并根据初等元胞自动机迭代结果进行索引,设计系统索引规则;然后,设计耦合系数生成算法,根据初等元胞自动机的初值和2个保密整数获取耦合系数的数值,将耦合映像格中的格子索引对应到元胞自动机中的细胞索引,再根据算法规则返回相应的扰动值和扰动符号,解决了在有限计算精度下混沌系统的动力学退化问题,增强时空混沌系统的混沌特性;最后,设计了基于伪随机耦合映像格的混沌扩频通信方案,对伪随机耦合映像格混沌扩频码进行直接序列扩频和二进制相移键控调制。仿真实验结果表明,混沌扩频码通过了伪随机性测试,具有良好的伪随机性,且所提方案具有良好的误码率性能。In order to solve the problem of uneven output distribution of chaotic systems and the degradation of chaotic system dynamics under the limited precision,a pseudo-random coupled map lattice chaotic spreading code generation algorithm is proposed based on the iterative rules of elementary cellular automata and coupled map lattices.First,elementary cellular automata is used to control the coupling objects of each lattice in coupled map lattices.The initial iteration value is generated by the exclusive or operation of different elementary cellular automata iteration rules.The index is carried out according to the elementary cellular automata iteration results,and the system index rules are designed.Then,the coupling coefficient generation algorithm is designed,and the coupling coefficient value is obtained according to the elementary cellular automata initial value and two secret integers.The lattice index in the coupled map lattices is mapped to the cell index in the elementary cellular automata,and then the corresponding disturbance values and disturbance symbols are returned according to the algorithm rules,which can effectively weaken the degradation of the dynamic characteristics of the chaotic system and enhance the chaotic characteristics of the spatiotemporal chaotic system.Finally,the scheme of chaotic spread spectrum communication system based on pseudo-random coupled image lattice is designed.The pseudo-random coupled map lattice chaotic spread spectrum code is directly spread and modulated by binary phase shift keying.The simulation results show that the chaotic spread spectrum code has passed the national institute of standards and technology test and has excellent pseudo-randomness.The proposed scheme has good bit error rate performance.

关 键 词：初等元胞自动机 耦合映像格 耦合系数 扰动 混沌扩频 

分 类 号：TN918.91[电子电信—通信与信息系统]