哈尔滨工业大学华德应用技术学院毕业设计（论文）摘 要扩频技术原来是只应用在军事领域的通信技术，而如今第三代移动通信技术已经走进了老百姓的日常生活。3G 技术的核心技术正是扩频技术。因此身处在 3G 时代，对扩频技术的性能的研究显得格外重要。扩频技术以其优越的抗噪声性能，和其在码分多址系统中的作用得到了很高的重视和很大的发展。本文阐述了扩频通信的基本原理。然后根据基本的数字通信的基本原理建立了一个宽带无线数字通信系统，并用 Matlab 软件进行的系统仿真及抗噪声性能的分析。此系统用了二进制相移键控作为调制方法，用循环冗余校验以及交织技术作为差错控制，并做了简单的数据帧格式设计。关键词：直接序列扩频 相移键控 Matlab 循环冗余校验 交织-I-哈尔滨工业大学华德应用技术学院毕业设计（论文）AbstractAt first spread spectrum technology was only for military use. But now the third generation mobile communication technology has been used by almost everyone. The core of the 3G is spread spectrum technology. So it is important to study the performance of the spread spectrum system.Spread spectrum technology has been pay lot of attention and great developed. This article introduced the principle of spread spectrum, and designed a basic wireless broadband digital communication system based on principle of digital communication which use Direct Sequence Spread Spectrum as the main technology, then simulate it use Matlab to check its noise immunity. this system use bpsk as its modulate technology ， use Cyclic Redundancy Check and Interleaving for error control. this system has designed a simple form of frame.Keywords：Direct Sequence Spread Spectrum; Cyclic Redundancy Check; Interleaving; Bpsk; Matlab-II-哈尔滨工业大学华德应用技术学院毕业设计（论文）目 录摘 要..................................................................................................................IAbstract................................................................................
