Análisis mediante simulación de la propagación de señales UHF en túneles subterráneos en base al modelo de trazado de rayos (caso de estudio Metro de Quito)

Abstract

The Ray Tracing model is applied to analyze the propagation of a radio signal in the UHF band inside the Quito Metro tunnel. The model incorporates the principles of Geometric Optics to determine the behavior of an electromagnetic wave as if it were a ray that suffers multiple reflections. The elements that stand out in the simulation are: the 3D representation of the tunnel and the 3D representation of the geodesic ray source. In order to estimate the received power, it is assumed that the tunnel walls are a homogeneous reflecting medium, the losses inside the tunnel are based on the Friis Equation to determine the losses in the free space. The simulation is performed in Matlab. By means of a graphic interface, the input parameters can be modified. The study considers the placement of an antenna at the entrance and exit of each section of the tunnel. The work includes the presentation of the power delay profile, the power fading graph and a heat map to visualize the power level of the signal inside the tunnel.