高速无线局域网的研究

【作者】 刘德志；

【导师】 宋耀良；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2003， 硕士

【摘要】 无线局域网是融合无线通信技术和计算机网络技术一种新兴网络通信技术。本文首先从技术上论述了802.11协议介质访问控制(MAC)层结构与规范，研究了IEEE 802.11体系高速无线局域网络的标准、配置和组成等问题。接着在详细阐述了802.11b协议核心调制技术—互补码键控(CCK)的原理的基础上，本文提出并实现了一种峰值传输速率为11Mbps的802.11b PCMCIA高速无线网卡的硬件电路设计方案，在2.4GHz频段该网卡可在14个工作信道上自动切换，实现高速突发数据的可靠传输。另外本文还对最高传输速率为54Mbps的802.11a高速无线局域网系统进行了探索性研究，讨论了OFDM调制技术在无线局域网中的应用；结合802.11a物理层数据帧结构特点，提出了一种基于前导训练符号序列的频域自相关时间和频率同步方法，此方法具有定时精度高、频偏估计范围宽和同步建立迅速等特点，也适合于其它帧通信应用场合。最后给出了一个完整802.11a无线局域网收发系统的结构框图，并对它进行了计算机仿真。更多还原

【Abstract】 Wireless LAN is a new network communication technology that has integrated modern wireless and computer network communication technology. On the technology point of view, this paper discusses the framework and operation of 802.11 MAC layer, and studies the specification, configuration, and structure of an 802.11 system high speed WLAN. After elaborating the principle of an 802.lib key modulation scheme - Complementary Code keying (CCK), this paper proposes and realizes a hardware circuit solution of 802.11b PCMCIA WLAN interface card, which can reliably offer a maximal 11Mbps data rate and freely switch within 14 working channels in 2.4GHz frequency band. Furthermore, this paper exploringly studies an 802.1 la high-speed WLAN with the 54Mbps data rate, and presents a sort of time synchronization and frequency offset estimation method based on the frequency domain auto-correlation of the unique preamble training sequence of 802.11 PLCP frame; the method have the high time precision, the wide frequency estimation range and short convergence process; and moreover, it can applied to other frame communication system. In the end, the paper presents the architecture figure of 802.1 la WLAN transceiver, and implements a computer simulation scheme via ADS simulation software.更多还原