混沌扩频序列的优选算法及其系统性能研究

为了获得多址通信中优良的伪随机特性码组,提出了一种混沌序列的优选算法。通过对混沌系统迭代结果的截断和量化处理,根据扩频序列的理想特性和多址干扰指数,给出了优化混沌序列码组的具体步骤,并对传统的Gold序列和多种混沌序列的码组性能作了比较和分析。对DS/CDMA系统性能的仿真结果表明,优选混沌扩频序列的相关性能优于传统的伪随机扩频序列,有利于解决CDMA移动通信中的抗多址干扰及多用户检测等关键问题,从而使混沌扩频系统的抗干扰能力和抗破译能力得到增强。

Optimization algorithm for chaotic spread-spectrum sequences and its system performance analysis

In order to gain a good property group of pseudorandom sequences in code division multiple access communication, an optimization algorithm based on the optimized chaotic spread-spectrum sequences is proposed. The method based on the properties of spread-spectrum sequences and multiple access performance index are presented, and 5 kinds of optimized sequences obtained by repeating a truncated and quantized chaotic time series are compared with classical Gold sequences in performance. The computer simulations show that the DS/CDMA systems based on these optimized chaotic spreading sequences perform much better than the conventional pseudorandom ones. It is very useful in solving key problems related to correlation characteristics in CDMA mobile communications, such as multiple access interference and multi-user detection, so the antijamming ability and security of the chaotic communications are greatly improved.