基于IM映射的超混沌扩频序列的研究

Research on Hyperchaotic Spreading Sequences Based on Ikeda Map

通过对二维超混沌映射IM进行过抽样的运算处理,得到了一种新的映射OIM,并由此生成了超混沌二值扩频序列OIMBS(Over-sampled Ikeda Map Binary Sequences),该一维序列在相关特性、平衡性及保密性等方面均优于IM二值序列IMBS(Ikeda Map Binary Sequences)。另外,根据一维扩频码的最优筛选策略优选出若干组Logistic Map二值序列、IMBS和OIMBS用于传统的DS-CDMA通信系统,在多种信道中仿真了系统的误码情况,结果证实了应用OIMBS的通信系统误码率要远低于采用其他2种序列的系统。

By over-sample operations on 2 - D hyperchaotic map,IM,a novel map named OIM is propesed for the generation of OIMBS （Over-sampled Ikeda Map Binary Sequences）. OIMBS are found possessing of better correlation property, balance property, and having higher security than IMBS（Ikeda Map Binary Sequences）.Based on the optimal filter strategy for 1 - D spreading sequences, Logistic Map binary sequencos, IMBS and OIMBS are optimally selected for conventional DS- CDMA communication system respectively, and it is concluded that under a variety of channel conditions, the Bit Error Rate performances of the communication system which adopts OIMBS are anyway more desirable than those of other two systems.