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

Abstract

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-toground 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.

Mobile relays for urban rail transportation systems

“…Based on the fact that a train travels in fixed trajectories, the proposed measurement procedure can shorten the handover time, according to the authors. In [33] the authors study handover performance based on dual antennas and mobile relay for high speed railways. This work focuses on reducing the handover outage probability.…”

Planning Optimization of the Distributed Antenna System in High-Speed Railway Communication Network Based on Improved Cuckoo Search

“…Thus, using the DAS may be not necessary when the train is within the scope of the stations. Moreover, d v is actually the distance between the electric centers of the TX (DAS) antenna and RX (train) antenna, and it has been chosen as several different values in previous work, for example, 50 m [39], 60 m [40], and 100 m [41]. In our simulation, we set it as a fixed value of 50 m for simplification.…”

Remote Antenna Unit Selection Assisted Seamless Handover for High-Speed Railway Communications with Distributed Antennas

“…Aiming at releasing these problems, a lot of research work have been done in the literature [2] - [6]. To release the first problem, two-HST antennas were adopted in [2], in which during the handover, the front antenna of the train carries out handover while the rear antenna keeps connecting with BS.…”

“…To release the second problem, the distributed antenna system (DAS) cell architecture was introduced to HSR systems [3], [4], which also improves the system supported data rate as the remote antenna unit deduces the distance between the BS and the train. To inherit the advantages of both two-HST antennas and DAS cells, [5] and [6] investigated them in a single HSR system to improve the handover performance, where however, only traditional/blanket transmission scheme was considered.…”