Indoor Wireless Channel Modeling for UWB Communications Using Finite Difference Time Domain Method

In this paper, a two-dimensional (2-D) transverse magnetic (TM) mode of finite difference time domain (FDTD) method is used to simulate the indoor radio wave propagation and model the path loss of an ultra wideband (UWB) channel. The modulated Gaussian pulse satisfied the UWB signal definition and the Federal Communications Commission (FCC) indoor limit spectral mask is used as the UWB excitation signal. The propagation of electric field at each example time step is demonstrated. The power delay profiles along the specific distances are shown. The free space path loss obtained from the FDTD method is shown and verified by comparing with that obtained from the extension of Friis ' transmission formula. After that, we evaluate the path loss effect with our proposed model in an indoor environment. Our proposed model is a room structure, which consists of gypsum board, plywood door, 3 metallic cabinets, brick and dry concrete walls. The line-of-sight (LOS) and obstructed (OBS) environments are considered. Furthermore, these obtained data model the path loss by using the regression model. The probability density function (PDF) and cumulative distribution function (CDF) of fading are illustrated. From the results, we can see that the FDTD simulation is convenient and flexible for the site-specific and statistical models of the UWB indoor radio wave propagation