5G wireless technology is expected to provide much improved performance in terms of data rate, reliability, latency, and mobility in various use cases and deployment scenarios. One of these promising 5G deployment scenarios is the high speed train scenario, which aims to offer broadband access to passengers on a high speed train running up to 500 km/h. Such very high mobility imposes considerable technical challenges to be dealt with during the 5G standardization phases. This article introduces the technical specifications of 5G NR with particular attention on the high speed train scenario. Based on the concrete high speed train scenario description, various NR design elements to achieve such very high mobility are discussed including numerology, frame structure, reference signals, multi-antenna schemes, cell search, random access, and mobility support. Discussions on the challenges and perspectives for high speed train communications of Beyond 5G are also provided.

中文翻译：

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5G中的高速列车通信：缓解超高移动性影响的设计元素

预计5G无线技术将在各种用例和部署场景中在数据速率，可靠性，延迟和移动性方面提供更高的性能。这些有前途的5G部署方案之一是高速火车方案，其目的是为时速达500 km / h的高速火车上的乘客提供宽带接入。如此高的移动性给5G标准化阶段带来了巨大的技术挑战。本文介绍5G NR的技术规范，并特别关注高速列车场景。根据具体的高速列车场景描述，讨论了实现这种高移动性的各种NR设计元素，包括命理，帧结构，参考信号，多天线方案，小区搜索，随机访问，和移动性支持。还提供了有关超越5G的高速列车通信的挑战和前景的讨论。