Research And Design On Fast-Move-Supported WLAN

At present, Wireless Local Area Networks (WLAN) is widely used. To meet the demand on wideband wireless data accessing whenever and wherever, new kind of WLAN should be developed by researching in the aspect of network structure and enhancing the capability of supporting-mobile.In this paper, the main research is on the technologies of supporting-fast-move WLAN。 In the railway system there are the characteristics of moving fast, wide scope, stead track, which provide the convenience for researching on the supporting-fast-move WLAN with the simple network structure and the relative steady environment. Wireless mesh network topology and network planning are used to design the network structure of the new WLAN system. With the new WLAN network structure, the technology of physical layer is deeply researched. In the environment of time variety channel, the channel estimation of MIMO-OFDM system is been researched as the physical layer technology. Two kinds of model of MIMO-OFDM system are been developed, STTC-OFDM and SFBC-OFDM. The pilot based MMSE algorithm of MIMO-OFDM is deeply researched and detailed analyzed. With the result of system simulation, useful conclusion is gotten, which could take a directive effect on the new WLAN development. In the last part of this paper, the fast handoff technology in the new WLAN system is briefly analyzed.