Train-to-Train (T2T) communication is expected to increase efficiency of train operation and reduce life cycle cost in construction for urban rail transit system. In this paper, we introduce the millimeter wave (mmWave) and multiple input multiple output (MIMO) technologies to improve the reliability and capacity of T2T communication, and a novel mmWave MIMO based transmission scheme is proposed. By applying the hybrid precoding at the T2T transceivers, the system design cost and power consumption are greatly reduced, while satisfying the requirements of spectral efficiency and signal to noise ratio (SNR). Simulations results show that the performance of the proposed precoder approaches the one under unconstrained digital precoder. Compared with the analog precoding scheme, the proposed scheme can achieve at least a 7-fold increase in spectral efficiency. By analyzing the effects of the number of data streams, the number of radio frequency (RF) chains, and the T2T communication distance on the system performance, the proposed scheme is confirmed to provide theoretical guidance for practical design of T2T communication.

中文翻译：

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增强基于混合预编码的火车到火车通信的传输

火车到火车（T2T）的通信有望提高火车运营效率，并减少城市轨道交通系统建设中的生命周期成本。在本文中，我们介绍了毫米波（mmWave）和多输入多输出（MIMO）技术以提高T2T通信的可靠性和容量，并提出了一种基于mmWave MIMO的新型传输方案。通过在T2T收发器上应用混合预编码，可以大大降低系统设计成本和功耗，同时满足频谱效率和信噪比（SNR）的要求。仿真结果表明，所提出的预编码器的性能接近无约束数字预编码器的性能。与模拟预编码方案相比，所提出的方案可以使频谱效率至少提高7倍。通过分析数据流数量，射频（RF）链数量以及T2T通信距离对系统性能的影响，确定了该方案，为T2T通信的实际设计提供了理论指导。