Propagation Modeling

A typical cellular radio system consists of a collection of base stations (BSs) that are relatively free from local scatterers. The BS antenna height and placement affects the proximity of local scatterers. In a macrocellular environment, the BS antennas are usually well elevated above the local terrain. No direct line-of-sight (LOS) path exists between the BS and mobile station (MS) antennas, because of the natural and man-made objects that are in the immediate vicinity of the MS. As a consequence of reflections, scattering and diffraction, multiple plane waves arrive at a MS from many different directions and with different delays, as shown in Fig. 2.1. This property is called multipath propagation. The multiple plane waves combine vectorially at the receiver antenna to produce a composite received signal.