Time-dispersion simulation for microcellular systems in urban environments

Over the past decade the mobile communications industry has experienced phenomenal growth. As the number of communication devices continue to increase, high-capacity microcellular communication networks will grow. Fairly extensive work has been done to characterize narrow band propagation in terms of the mean signal strength and the fading characteristics. It is still necessary to adequately quantify the time-dispersion characteristics for wideband communication system, whose data rate exceeds the coherent bandwidth. But only few papers focused on the time-dispersion characteristics. For microcells, propagation modeling must take into account the exact positions, orientations, and electrical properties of individual buildings. A wideband channel have been simulated in the urban environments using the modified shooting and bouncing ray/image method, which is a site-specific prediction method. We investigate the effects on the time dispersion characteristics of the channel to complement an earlier study of propagation loss characteristics.