Wireless communications channel modeling based on numerical solutions of Maxwell equations

The field strength level of a received signal and its statistical distributions are important studies in wireless communication and network planning. In this paper, we perform numerical solutions of Maxwell equations based on two fast methods of solutions of method of moment (MoM) equations, multi-level fast multipole method (FMM) and the sparse matrix canonical grid method (SMCG). In the first problem, we solve a two-dimensional problem of urban area with distance of 1 kilometer at 900 MHz for macrocell/microcell studies. The fast and slow fading effects are studied. The distance power gradient is studied. In the second problem, we solve a three-dimensional scattering problem of scattering by random rough surfaces for ultrawideband (UWB) studies with bandwidth from 3 GHz to 10 GHz. The effects of pulse distortion and fast fading are studied. Results show that UWB has less fading compared with the narrow band pulse.