A Dual-Antenna and Mobile Relay Station Based Handover in Distributed Antenna System for High-Speed Railway

When a train speeds up to 350km/h, it is challenging for continuous wireless coverage due to a number of critical issues, e.g. frequent handover and drop-offs. To address this problem, this paper proposes a novel handover scheme based on the dual antennas and Mobile Relay Station (MRS) for High Speed Railway (HSR) Distributed Antenna System (DAS). The scheme enables the dual antennas controlled by the MRS to receive signals from multiple Remote Antenna Units (RAUs), thus obtaining diversity gain when the train moves within one logic cell. While the train runs through the edge of a logic cell, a dual-antenna handover scheme is adopted to enhance the handover performance. Thereby, the proposal improves the quality of the received signal and provides reliable communication for train-tog round network. The numerical analysis and simulation results show the proposed handover scheme can reduce handover frequency dramatically and provide the seamless access for HSR compared to the standard LTE handover scheme.