相位扩谱序列的设计准则及该直扩多址系统的性能研究

摘要

本文提出了一种基于连续相位调制(CPM)并用于直接序列扩频多址(DS/SSMA)的新型相位扩谱序列(PSS)，以及它的最佳设计准则。依据该准则并在调制指数为0.5的连续相频键控(CPFSK)条件下，通过穷尽搜索法得到了含有若干种不同周期长度的相位扩谱序列的集合。同时在瑞利衰落信道条件下，作者对采用相位扩谱序列的DS/SSMA系统的性能进行了研究，最后将采用PSS序列和传统直扩序列的DS/SSMA系统的性能进行了比较。%In this paper we propose a novel kind of phase spreading sequence (PSS) for direct sequence spread spectrum multiple access (DS/SSMA) with continuous phase modulation (CPM) ,and the optimal design criterion of PSS is obtained. Several sets with PSSs of various periodic lengths under the condition of continuous phase frequency shift keying (CPFSK) of modulation index h = 0.5 are constructed by exhaustive search based on this optimal criterion. The performances of PSS DS/SSMA system in Rayleigh fading channel are in-vestigated by theoretical analysis and numerical simulations. Finally, the comparisons between the performances of the systems with PSSs and the traditional PN sequence under the same conditions are also made.