摘要
直接序列扩频系统中起扩展频谱作用的扩频码性能的好坏直接影响到系统性能的好坏,针对由Logistic映射,Chebyshev映射,Tent映射等一维混沌映射直接产生的混沌扩频序列若干次迭代后陷入循环的可能,由若干不同初值的Chebyshev映射产生的混沌序列组合成新的混沌扩频序列,给出了具体的构造方法。通过理论与统计仿真结果分析可知,该混沌序列的特性满足伪随机序列的要求,有效地避免了周期窗口的出现。改进后的序列保持了混沌序列的特性,产生方法简单,易于复制,很适合用于DS/CDMA扩频通信系统中。
The performans of the spreading cords which play the role of spread spectrum in a direct sequence spread spectrum have a direct impact on system.In general,The chaotic spreading sequences directly from one-dimensional chaotic map which including the Logistic map,Chebyshev map,Tent mapping may fall into circulation after several iterations.A new chaotic spreading sequence based on Chebyshev map with different initial values is proposed in this paper,and the construction method is given in detail.Simulation results and theory analysis shows that the characteristics of the chaotic sequence meet the requirements of pseudo-random sequence and avoid the appearance of periodic windows effectively.The improved sequence maintained the characteristics of the chaotic sequence and the method is simple,easy-to-copy,so it is suitable for DS / CDMA spread spectrum communication system.
出处
《计算机安全》
2012年第1期26-29,共4页
Network & Computer Security
关键词
切比雪夫映射
混沌扩频序列
相关性
游程特性
chebyshev-map
chaotic spreading sequences
related features
run-length feature
