摘 要:随着现代通信技术的飞速发展及人们对通信需求的不断提升,扩频通信以 其抗干扰性强、误码率低、高频带利用率等优点,在军用及民用通信领域都具有广 泛的应用前景。本文在对扩展频谱通信技术的理论基础与实现方法研究的基础上, 利用 MATLAB 提供的可视化工具 Simulink 建立了扩频通信系统仿真模型,详细讲 述了各模块的设计,建立了仿真系统,并在给定仿真条件下对系统进行了仿真实 验,研究了扩频增益与输出端信噪比的关系,实验结果表明,在相同误码率下,增 大扩频增益,可以提高系统输出端的信噪比,从而提高通信系统的抗干扰能力。65404
毕业论文关键词: 扩频通信,误码率,Simulink 仿真
Abstract: As the rapid development of modern communication technology and people continue to enhance the demand for communication,spread spectrum communication with its anti-interference is strong,bit error rate low,high frequency band utilization rate etc.In the military and civilian communication fields has wide application prospect. In the theoretical basis of spread spectrum communication technology and implementation method research based on,Simulink provided by MATLAB established simulation model of the spread spectrum communication system,described in detail the design of each module,simulation system was established,and in a given simulation conditions on the system were simulation experiment,studies the relationship between the spread spectrum gain and output signal to noise ratio. Experimental results show that under the same bit error rate and increase the spread spectrum gain can improve the system output end of the signal to noise ratio,so as to improve the anti-interference ability of the communication system.
Key words: spread spectrum communication,error rate,Simulink.
目 录
1 绪论 4
1.1 引言 4
1.2 发展现状 5
1.3 解决的主要问题 6
2 扩频通信系统 7
2.1 扩频通信的基本原理 7
2.1.1 扩频通信的定义与分类 7
2.1.2 扩频通信的理论基础 8
2.1.3 扩频通信的主要性能指标 9
2.1.4 扩频通信系统的工作原理 10
2.1.5 m 序列 10
2.1.6 扩频通信的实现方法 11
2.2 扩频通信系统的特点 12
3 simulink 仿真模块 11
3.1 simulink 仿真过程 13
3.2 基于 simulink 发射机的设计 13
3.2.1 直接序列发射机的设计 14
3.3 基于 simulink 发射机的仿真 15
3.4 模型建立及主要模块设计 16
4 扩频通信系统的仿真结果 17
4.1 对产生 m 序列的仿真 17
4.2 对直接扩频通信系统的仿真 18
4.3 扩频增益与输出端信噪比的关系 19
结论 20
参考文献 21
致谢 22
1 绪论
1.1 引言