Wireless Perception of High-Speed Railway Communication: Challenges, Framework, and Future Directions

The rapid development of 5G, 6G, and beyond is driving the European Union's "Shift2Rail Plan," which aims to promote the adoption of next-generation communication technologies for high-speed railways (HSR) in order to evolve into future smart railways. This plan emphasizes the shift from wired to wireless communication. To achieve the vision of future HSR communications, it is critical to establish a theoretical framework for the wireless perception of high-speed trains, which faces significant challenges related to reliable communication and thorough perception. However, there is currently a lack of related descriptions of the framework between train units and carriages. This article aims to address this gap by focusing on key scientific issues, such as the time-varying, non-smooth channel propagation mechanism in the space-time-frequency domain, and the optimal perception mechanism of ultra-reliability, low-latency, and large-capacity scenarios. Specifically, this article aims to revolutionize four potential key technologies: the double-dynamic time-variant non-stationary wireless channel model; the ultra-reliable, low-latency, and large-capacity wireless communication network; the thorough perception mechanism that integrates multi-source autonomous perception information fusion; and the collaborative interactive perception system that fuses adaptive centralized sampling and flexible marshaling. Based on these technologies, we aim to resolve the challenges related to intelligence, light weight, and flexible marshaling of trains, and provide technical support for the wireless communication and perception integrated system of next-generation HSR.