基于SystemView扩频通信系统设计与仿真.doc

毕业论文 学 院 信息电子技术 专 业 通信工程 班 级 0级班 学 籍 号 姓 名 指导教师 2011年6月1日 摘 要 扩频通信系统与常规的通信系统相比具有很强的抗干扰能力如抗人为干扰、抗窄带干扰、抗多径干扰等并具有信息隐蔽、多址必威体育官网网址通信等特点已从军事应用向民用通信应用迅速发展利用Systemview软件作为平台对扩频通信中最典型的扩频工作方式———直接序列扩频系统(DSSS)进行了仿真分析通过时域波形对比发送端和接收终端两个波形图可明显观察到解扩后的信号与输入的原始信号波形基本一致，并注意到接收端有一些毛刺 这是由于时间脉冲信号的脉宽有误差而造成的。通过对频谱波形的分析可知，扩频系统抗噪声能力很强，当不断加大噪声的幅度达到系统的干扰门限时 则不能准确地恢复原始信息。结果证明随着扩频增益的增大系统的误码率越小同时扩频系统性能的好坏很大程度上还取决于扩频码的特性。 关键词：Abstract The spread spectrum communication system and the conventional communication system, have very strong compared the anti-interference ability, such as HIV human interference, fight narrowband interference, fight multipath interference, etc, and has the information hiding, multiple address secret communication and other characteristics, already from military application to civil communication application developing rapidly. Use Systemview software platform to spread spectrum communication, as the most typical spread spectrum work--way direct sequence spread spectrum system (DSSS) are analyzed; Through the time domain waveform contrast the sending end and receiving terminal two waveform figure, can obviously observed after the expansion, solution and the input signal of the original signal waveform, and pay attention to the same at the receiving end has some burr, this is due to the time pulse signal pulse width is caused by the error. Through the analysis of the waveform of frequency spectrum, it is known that spread spectrum system anti-noise ability is very strong, when rising of the amplitude, achieve system noise interference threshold, it cant accurately restored the original message. Results show that with the increase of spread spectrum gain, the system ber is smaller, and spread spectrum system the performance to a large extent depends on the characteristics of the code is spread spectrum. Key words：Spread spectrum communication; Simulation; SystemView 目 录摘 要 i Abstract ii 第1章 绪论 1 第2章 直序扩频通信系统 2 2.1 基