High-speed Wireless Lan

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.