Wi-Fi技术原理及应用-电子技术应用.DOC

摘要 随着网络的普及，越来越多的人享受到了网络给人们生活带来的方便。但是上网地点的固定，上网工具不方便携带等问题，使人们对无线网络更加的渴望。而Wi-Fi技术的诞生，正好满足了人们的渴望，也使得Wi-Fi技术越来越受到人们的关注。 所谓“Wi-Fi”其实就是Wireless Fidelity 的缩写，意思就是无限局域网。它遵循IEEE所制定的 802.11x系列标准，所以一般所谓的802.11x系列标准都属于Wi-Fi。根据802.11x标准的不同，Wi-Fi的工作频段也有2.4G/HZ和5G/HZ的差别。但是Wi-Fi却能够实现随时随地上网需求，也能提供较高速的宽带接入。 当然，Wi-Fi技术也存在着诸如兼容性，安全性等方面的问题，不过它也凭借着自身的优势，占据着主流无线传输的地位。 本文首先对Wi-Fi的技术背景和发展情况做了简单的叙述，然后着重研究了Wi-Fi技术的原理，其中包括了Wi-Fi的性能指标，实现Wi-Fi的关键技术，Wi-Fi协议，其次讨论了Wi-Fi的网络的构成，和传输方式，最后对Wi-Fi的应用做了一些介绍，并对Wi-Fi技术未来的发展做出了假设和展望。 关键词：Wi-Fi；IEEE802.11；直序扩频技术;跳频技术 Abstract For the popularity of the network, more and more people have felt its convenience. However, the restricted area of the net and the inconvenience of the tool’s taking make people strongly eager for Wi-Fi. Wifi’s producing which satisfied people’s desire has made it more attractive. , Wifi is the abbreviation of wireless fidelity. It obeys the standard 802.11X IEEE. That is to say, standard 802.11X belongs to wifi. According to the different standard 802.11X, wifi has operation band in 2.4G/HZ and 5G/HZ. Even though there are also some problems like Compatibility and net work security of wifi, it also occupied the mainstream wireless transmission with its advantages. This article firstly briefly introduces the background and the development of wifi, focusing on the technology principles which include its performance index, the key technologies of its realization and the wifi protocols. Then it discusses the wifi’s networking and its transmission. Finally, it presents the application of wifi and make the hypothesis and the outlook of wifi’s development. Keywords: Wi-Fi; IEEE802.11 ;Direct-sequence Technique ;FHSS 目录 摘要 I Abstract II 绪论 1 1 Wi-Fi概述 2 1.1Wi-Fi技术背景与发展 2 1.1.1 Wi-Fi概念 2 1.1.2 Wi-Fi技术的背景 2 1.2 Wi-Fi技术的发展与特点 3 1.2.1 Wi-Fi技术的发展 3 1.2.2 现有Wi-Fi技术特点 4 2 Wi-Fi技术的原理 5 2.1 Wi-Fi技术性能指标和关键技术 5 2.1.1 Wi-Fi的性能指标 5 2.1.2 Wi-Fi的关键技术 5 2.2 Wi-Fi的协议及MAC层关键技术 8 2.2.1 CSMA∕CA协议 8 2.2.2 BTMA协议 8 2.2.3 MAC层IEEE802.11e协议 9 2.3 Wi-Fi技术的结构 10