硕士论文.doc

硕士论文
扩频通信系统的扩频序列设计研究
摘要
首先,本文对传统的m序列设计进行了分析,发现了传统基于GF(2)的m
序列生成方法的不足,提出了应用复制理论生成m序列的设计方法,可以在不
知道生成多项式的前提下完整地生成m序列;同时建立了一套扩频序列高效计
算机搜索模型及其算法,应用该算法,通过计算机搜索并构造挑选得到了大量的
m序列优选对及扩频序列联通集。
其次,本文对Walsh正交扩频码作了一定研究,通过对常规生成Walsh码的
设计方法分析,提出了一种新型的Walsh函数生成及发生器设计方案。
最后,文章对混沌通信系统的扩频序列进行研究,包括Logistic-map及其改
进型映射和Kent映射混沌序列。介绍了Logistic-map模拟混沌序列的生成实现
方法,并通过matlab将模拟混沌序列的相关性能和理论分析作了一定比较。从
数学上得到了改进型Logistic-map混沌序列的统计特性,并通过仿真,分析了其
相关性能。同时研究了Kent映射混沌序列和Logistic-map映射混沌序列的二进
制序列性能,通过对序列的均值、自相关函数、互相关特性、相关旁瓣与互相
关均方根值、互相关峰值、游程与平衡性等多方面的分析比较,说明两种混沌映
射序列均适合于扩频通信系统,而Kent混沌序列更适合于保密性和抗干扰性强
的通信场合。
关键词:m序列复制理论联通集Walsh码Logistic-map混沌序列
Kent混沌序列扩频通信
硕士论文
扩频通信系统的扩频序列设计研究
Abstract
The design of conventional m-sequence is researched in the paper firstly.
Shortage of generating m-sequence based on GF(2) is found. The design method of
generating m-sequences applied copy theory is advanced. It generates m-sequence
without knowing about creating polynomial. In the same time, an puter
search model and its new algorithm are presented. By the way of puter to
search and select, we can make a great deal m-sequences optimum pairs and the
correlation congregate. Then in the third part, the paper researches Walsh code a
certain extent, and it bring out a new way to generate Walsh pared with
traditional way.
The fourthly part in this paper analyzes the spectrum sequence in chaotic
communication system finally. for example, Logistic -map and its modified chaotic
sequence and Kent chaotic sequence. It introduces the realizing way for simulative
Logistic -map chaotic sequences, and pares the correlation performance of
simulative chaotic sequences with theory analyzing. Then this paper derives the
mathematical expression of statistical properties of chaotic sequences generated by
improved Logistic -map. The simulation results are very close to theoretical values.
Finally, the Kent binary chaotic sequence is investigated pared with the
improved logistic binary chaotic seque