Channel Characteristics for 5G Systems in Urban Rail Viaduct Based on Ray-Tracing

Channel characterization is essential for the research, system development, network planning of wireless communication system. In this paper, the channel parameters for 5G system in urban rail viaduct scenario, including path loss, delay spread, angular spread, Doppler shift and Doppler spread are extracted based on ray-tracing (RT) simulation technology. The ray-tracing simulation results show that: 1) due to high gain antenna used in BS, the relatively better signal coverage in cell edge, but the relatively worse signal coverage in the vicinity of BS; 2) the delay spread is relatively low due to the strong light-of-sight (LoS) path; 3) when the train is in the vicinity of the BS, the Doppler shift is very low and the RMS Doppler spread is very high, and vice versa. The obtained channel characteristics are helpful for channel modeling, system test and network planning of 5G system in urban rail.