As a vital vertical industry empowered by the sixth-generation mobile communication system (6G), the vision of “smart rail mobility” requires a seamless wireless connectivity with the ultra high-data rate on the order of 100 Gbps or even more. This forms a strong driving force for exploiting the terahertz (THz) band where the available spectrum is massively abundant. In this paper, the smart rail mobility channel is characterized through ultra-wideband (UWB) channel sounding and ray tracing (RT) at 300 GHz band with an 8 GHz bandwidth in the five scenarios – Train-to-infrastructure (T2I), Inside station, Train-to-train (T2T), Infrastructure-to-infrastructure (I2I), and Intra-wagon. Corresponding channel characteristics such as path loss, shadow fading, Rician $K$ -factor, root-mean-square delay spread, azimuth/elevation angular spread of arrival/departure, and cross-polarization ratio are extracted and analyzed. Based on realistic channel information, the performance of THz communication is investigated in terms of channel capacity for all above five scenarios with various antenna patterns and weather conditions (except Intra-wagon) – sunny, rainy, and snowy. The results provide valuable insights into the system design and evaluation for THz communication enabled Smart Rail Mobility.

中文翻译：

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支持智能轨道交通的太赫兹通信的信道特性和容量分析

作为第六代移动通信系统（6G）赋能的重要垂直行业，“智能轨道交通”的愿景需要100Gbps甚至更高的超高数据速率的无缝无线连接。这形成了开发可用频谱非常丰富的太赫兹 (THz) 频段的强大驱动力。在本文中，智能轨道交通通道的特点是在 300 GHz 频段的超宽带 (UWB) 通道探测和光线追踪 (RT)，在五种场景中——火车到基础设施 (T2I)，内部车站、火车到火车 (T2T)、基础设施到基础设施 (I2I) 和车厢内。对应的信道特性，如路径损耗、阴影衰落、Rician$K$ 因子、均方根延迟扩展、到达/离开的方位角/仰角扩展以及交叉极化比被提取和分析。基于真实的信道信息，针对上述五种不同天线模式和天气条件（车内除外）——晴天、雨天和下雪的场景，从信道容量方面研究了太赫兹通信的性能。结果为支持太赫兹通信的智能轨道交通的系统设计和评估提供了宝贵的见解。