A comparative study of ray tracing and FDTD for indoor propagation modeling

Ray tracing is a high frequency approximation used for site-specific propagation modeling. In the high frequency approximation, the effect of the individual scattering elements on a body or collection of bodies are considered independently. However, as the scatterer size approaches the wavelength of operation, some of the assumptions in the high frequency approximation become invalid. A numerical experiment designed to show the dependence of the ray tracing method on the feature size is presented. Comparison is made between a full-wave, 3-D electromagnetic simulation provided by the finite difference time domain (FDTD) method and a simulation based on ray tracing. Simulation results are presented and the consequences of the information obtained from these experiments are discussed.