A Study on Entrance Link Employing MIMO/Unsymmetrical STBC Scheme in Wireless Lan Service over High-speed Vehicle Environments

Abstract

To solve the problem of traffic proliferation in the mobile communications, traffic offload over wireless LAN systems has been proposed as the one of promising solutions. High-speed and large-capacity communication has been realized by wireless LAN systems, but in the high-speed moving environments, BER performances degrade due to influence of Doppler frequency spread. In this study, the entrance link using the IEEE802.11ac standard for public wireless LAN services in high-speed trains is proposed for improving the capacity of the whole system by employing not only MIMO (Multiple Input Multiple Output) to increase the transmission rate, but also STBC (Space-Time Block Coding) to extend the distance. By applying unsymmetrical STBC for up and down-link, the communication distance between a base station and a train can be extended and it is confirmed by simulation including a passing pattern and stopping/starting pattern that the communication capacity can be increased.