一种高安全性的复合混沌序列的性能研究

基于Logistic型混沌序列及Chebyshev型混沌序列构造出一种新的复合型混沌序列。对该复合型混沌序列的初值敏感性和复杂度等混沌性质以及平衡性、相关性等扩频性能进行了仿真研究。仿真结果表明，该复合型混沌序列有着更强的初值敏感性和更高的复杂度；除此之外，该复合型混沌序列在平衡性、自相关、互相关方面性能不仅优于原混沌序列，而且与应用在GPS系统中的P码相比，在相关性性能方面也有优势。本文提出一种序列优选方式，通过该优选方法选出的复合型混沌序列数目比Logistic型和Chebyshev型混沌序列的优选序列数分别多出31%和67%。该复合型混沌序列是一种安全性高，扩频性能优良，生成简单，序列数目众的扩频码片。

Performance of a new compound chaotic sequence with high security

Based on the Logistic chaotic sequence and Chebyshev chaotic sequence, a new compound chaotic sequence is proposed. Simulations are performed to study the chaotic properties and spread spectrum properties such as initial sensitivity and correlation of this new compound chaotic sequence. The simulation results show that the compound chaotic sequence bears a stronger initial sensitivity and a higher level of complexity. The compound chaotic sequence is not only superior to the original chaotic sequence at balance and correlation performance, but also shows some advantages over the P-code which has been applied in the GPS system. An optimized selection algorithm is proposed to select a group of chaotic sequences with good performance. The results of this algorithm show that the compound chaotic sequences outnumber Logistic and Chebyshev chaotic sequences by about 31% and 67% respectively, which means that the compound chaotic sequence owns the largest number of sequences with satisfied properties. Therefore, the compound chaotic sequence is a kind of spread spectrum sequence which can be easily generated and bears a high level of security and good spread spectrum performance.