Modeling and Simulation of Electromagnetic Wave Propagation Using a Hybrid of Ray-Tracing and FV/FDTD Method in Indoor Environment

Growing interest in providing and improving radio coverage for mobile phones and wireless LANs inside buildings has recently emerged. The need of such coverage appears mainly in office buildings, shopping malls in very complex environment. This project presents a hybrid technique based on combining ray tracing and finite volume/finite-difference time domain (FV/FDTD) methods for modeling of indoor radio wave propagation. Ray tracing is used to analyze wide area and FV/FDTD is used to study areas close to complex discontinuities where ray-based solutions are not sufficiently accurate. The hybrid technique ensures improved accuracy and practically in terms of computational resources at the same time since FV/FDTD is only applied to a small portion of the entire modeling environment. Examples of applying the method for studying indoor structures are given at 2GHz.Numerical results are compared with known exact solutions or results of full wave analysis or traditional ray model to demonstrate the accuracy, efficiency, and robustness of the novel method. Cumulative distributions of field envelope obtained from the hybrid method show close resemblance to Rayleigh distribution, which conforms to the reported measurement results.