Deterministic Indoor Wave Propagation Modeling
Lajos Nagy, Budapest University of Technology and Economics,
Department of Broadband Infocommunications and Electromagnetic Theory
Department of Broadband Infocommunications and Electromagnetic Theory
The next generation mobile access network system design needs more precise characterization of the radio channel and needs sophisticated propagation models, because of the decreasing cell sizes and of higher data rates. In particular, the Especially planning of the coverage in tunnels and indoor spaces causes design problems without these models.
Indoor propagation problems for wideband radio systems are widely investigated widely and one of the today applied approach of modeling is the ray-tracing, ray-launching method. These ray methods are efficient for parallel-perpendicular scenarios but there is a common problem when tracing the rays for curved surfaces. The other disadvantage of the ray methods is the difficulty in describing the diffraction for a complex scenario. The specific case of the straight circular tunnel can be modeled analytically as a waveguide with circular cross-section.
Each of the two previous models has a disadvantage by modeling our problem:, the ray tracing needs huge running time because on the curved surface reflection the number of rays in bundles has to be increased, whilst the analytical method is not able to handle the complex propagation problem in presence the vehicle.
In our investigation the Finite Difference Time Domain method was proposed and used to analyze the 2 and 3 dimensional indoor wave propagation problems. We are demonstrateing the efficiency and flexibility of FDTD for curved tunnel, indoor office and special EMC cases [11-13].
Indoor propagation problems for wideband radio systems are widely investigated widely and one of the today applied approach of modeling is the ray-tracing, ray-launching method. These ray methods are efficient for parallel-perpendicular scenarios but there is a common problem when tracing the rays for curved surfaces. The other disadvantage of the ray methods is the difficulty in describing the diffraction for a complex scenario. The specific case of the straight circular tunnel can be modeled analytically as a waveguide with circular cross-section.
Each of the two previous models has a disadvantage by modeling our problem:, the ray tracing needs huge running time because on the curved surface reflection the number of rays in bundles has to be increased, whilst the analytical method is not able to handle the complex propagation problem in presence the vehicle.
In our investigation the Finite Difference Time Domain method was proposed and used to analyze the 2 and 3 dimensional indoor wave propagation problems. We are demonstrateing the efficiency and flexibility of FDTD for curved tunnel, indoor office and special EMC cases [11-13].