1、 1 摘 要 扩频通信技术(简称扩频通信)是一种新兴的高科技通信技术，具有 大容量、抗干扰、低截获功率等特点以及可实现码分多址(CDMA)等优点， 在军事和民用通信系统中都得到了广泛的应用，并成为下一代移动通信 的技术基础。在扩频通信系统中，直序扩频的应用最为广泛。首先介绍 扩频通信的基本原理及组成，重点论述了直序扩频通信在通信系统中的 使用。 MATLAB 因具有强大的数学计算、算法推导、建模仿真和图形绘制等 功能而广泛应用于各领域，本文利用 MATLAB 的 M 语言进行编程、仿真， 从而对 CDMA 无线通信系统的性能进行了分析。 在此基础上，通过实例介绍了建立系统仿真模型的方法。利用
2、MATLAB 软 件对 CDMA 无线通信系统的性能进行了分析。可见利用 MATLAB/SIMULINK 进行系统仿真简单、方便、形象、具体，是系统仿真较好软件之一。 关键词： 直序扩频通信系统； PN 序列产生器；误码率； 仿真；MATLAB 2 A Abstractbstract Spread spectrum communication is a sort of new high-tech communication technique, it has a number of internal advantages, such as large capacity, interferenc
3、e immunity, low probability of intercept, code division multiple access(CDMA)etc ,which make it get broad applications in civilian as well as military environments ,and become the technical groundwork of next generation mobile communications, Direct sequencing spread-spectrum was widely used. This p
4、aper introduces fundamental and constitutes of spectrum communication.Second it emphasizes elaborating spread-spectrums technique in the application of system. MATLAB has been using in a variety of fields as its powerful and universal functions on mathematics calculation, algorithm interference , mo
5、deling and simulation, graphic structure, etc, we are making use of MATLABs M language to design program and to make simulation on error rate performance and then to analyze the performance on CDMA wireless communication system . On this basis, the method to build system simulation model is introduc
6、ed with a simple example. Meanwhile a spreading-spectrum communication system is built to simulate it and prove its validity. Obviously, to simulate with MATLAB/SIMULINK is simple, convenient, visualized, special, which is one of the best simulation software. KeywordsKeywords: Direct Sequence Spread Spectrum Communication System; PN sequence generator; BER; simulation; MATLAB 1 目 录 引 言 . 2 1 扩频通信系统 5 1.1 扩展频谱通信的定义 5 1.2 扩频通信的理论基础 5 1.3 扩频通信的主要性能指标 6 1.4 扩频通信的主要特点 7 1.5 扩频通信系统的分类 10 1.6 扩频通信
