移动通信系统分集技术的研究.pdfVIP

移动通信系统分集技术的研究 摘 要 随着现代社会对无线通信需求的扩大，人们不断追求更高质量的无线传输速率 和服务质量。但无线通信中信号传输的多径衰落效应始终是困扰无线传输速率和提 高服务质量的最大问题，因此，人们采用了多种抗衰落技术。分集技术是抵抗衰落 最主要的技术之一，它的发展经历了时间分集频率分集，编码分集，到最近的空间 分集的过程。 要本文首先介绍了移动通信的发展历史、第三代移动通信概述、第三代移动通 信系统的传输技术，然后简单介绍了一下微波信道的多径传输，后面重点介绍了分 集技术，其中包括分集技术的分类，分集合并技术，分集合并技术的分析和性能比 较。分集合并技术包括：选择式合并，最大比值合并和等增益合并，通过比较得出， 在相同分集重数情况下，最大比值合并方式改善信噪比最多。文章最后作了小结。 关键词：移动通信，微波传输，分集，信噪比，合并 I 移动通信系统分集技术的研究 Abstract With the increasing demands of Wireless communications in modern times, people are seeking better quality of wireless transmission speed and services. But the improvement of wireless transmission speed and the quality of services are a1ways persecuted by multi-path fading effect of signal transmission. Therefore ，many technologies are introduced to resist multi-path fading. Among which diversity technique is one of the most effective technologies to resist multi-path fading. It has experienced the development of time diversity, frequency diversity, coding diversity, to the nearest space diversity process. This article first introduced to the history of the development of mobile communications, the third generation mobile communication outlined and the third-generation mobile communication system transmission technology. Then a brief introduction to the multi-channel microwave transmission paths. Behind the focus on diversity, including diversity of the classification, diversity combining techniques, and the analysis and performance comparison. Of the diversity com