Ray-Tracing-Based Channel Simulation for Ultra-High-Speed Train Communications in Evacuated Tubes

The operating speed of wheel-rail railway systems has approached its limit, to achieve higher economic operating speeds, evacuated tubes with low air resistance and low noise are considered a critical development direction for future ultra-high-speed rail technologies. The unique wireless channel propagation environment of evacuated tubes and their highspeed characteristics pose significant challenges for train-toground communication and channel modeling. Currently, there is a lack of research and practice focused on actual scenarios and systems. This paper employs ray tracing to investigate the radio wave propagation characteristics in evacuated tube environments, covering the 3.5 GHz frequency band. It models and simulates two radiation modes—leaky cables and antennas—and performs a comparative analysis of path loss under different deployment configurations. Additionally, the study examines the signal level coverage within the tube for various antenna positions and provides relevant recommendations to guide the design of communication systems for evacuated tube applications