Ray-tracing based modeling of ultra-wideband pulse propagation in railway tunnels

Ray tracing based on geometric optics can be utilized for generating propagation models for arbitrary and complex environments. These methods can be employed to determine important wireless channel characteristics such as coherence and delay spread. In this paper, an image theory based ray tracing method is used to study ultra-wideband propagation in complex tunnel environments such as curved tunnels and bifurcations. To validate the model, simulation results were compared to the experimental measurements performed in a hallway of an office building.