摘要扩频通信作为三大主流通信传输方式之一，在军用领域及民用领域都发挥着不可 替代的作用。无线通信系统的性能受到移动无线信道的制约，窄带干扰是一种人为加 入信道的干扰，对于军事无线通信会导致严重影响，所以必须采用信号处理的方法对 其进行削弱甚至消除。本文的研究建立在直接序列扩频通信系统中，尽管系统本身具 备一定的抗干扰能力，仍然需要采用干扰抑制技术来应对强干扰状况。变换域干扰抑 制技术是当前最有用的技术之一。83397

本文第一章主要介绍窄带干扰抑制技术的研究背景，简要概括了先进的解决方法； 第二章介绍了直序扩频通信系统，并对该系统的抗干扰能力进行了分析；第三章则具 体研究了基于直序扩频通信系统的 FFT 重叠变换干扰抑制算法的原理，以及具体实 现步骤；第四章采用了 MATLAB 中的动态仿真工具箱 Simulink 进行建模，并且分析 了 FFT 干扰抑制算法的可靠性；第五章则对本文进行了总结以及展望。

毕业论文关键词：扩频通信；窄带干扰；FFT 重叠变换；Simulink 仿真

Abstract At present, spread spectrum communication is one of the three main communication transmission modes, playing a major role in military and civilian communications。 The performance of the wireless communication system is constrained by the mobile radio channel。 Narrowband interference caused by human interference will cause a huge obstacle to the military radio communication, so it must be weakened or eliminated by the method of signal processing。 Although the research of this paper is based on the direct sequence spread spectrum communication system with a certain anti-interference ability, interference suppression techniques are still needed to cope with strong interference conditions。 Transform domain interference suppression is one of the most useful techniques。

The first chapter mainly introduces the research background of the narrowband interference suppression technology, and summarizes the advanced solutions。 In the second chapter, the direct sequence spread spectrum communication system is introduced, and the anti-interference ability of the system is analyzed。 The principle and the implementation steps of the FFT algorithm are studied in the third chapter。 In the fourth chapter, the system is carried out by

MATLAB/ Simulink, and the reliability of the FFT interference suppression algorithm is analyzed。 The fifth chapter makes a summary and prospect of this paper。

Keywords: spread spectrum communication; narrowband interference; FFT lapped transform; simulink

目 录

第一章 绪论 1

1。1窄带干扰抑制技术的研究背景 1

1。2窄带干扰抑制技术的发展历程 1

1。3窄带干扰抑制技术的具体算法 2

1。3。1 预测技术 2

1。3。2 变换域技术 4

第二章 扩频通信 6

2。1 扩频通信的原理 6

2。2扩频通信系统的种类 8

2。3扩频通信的优点 10

2。4直序扩频通信系统的抗干扰能力分析 11

第三章 直序扩频系统中 FFT 重叠变换干扰抑制算法 13

3。1系统综述 13