Date Added: Oct 2011
In most of the mobile or cellular systems, the height of the mobile antenna may be much lower than the surrounding structures. Thus, the existence of a direct or line of sight path between the transmitter and the receiver is highly unlikely. In such a case, propagation is mainly due to reflection and scattering from the buildings and by diffraction over and/or around them. So, in practice, the transmitted signal arrives at the receiver via several paths with different time delays creating a multipath situation at the receiver, these multipath waves with randomly distributed amplitudes and phases combine to give a resultant signal that Fluctuates in time and space. The phenomenon of random fluctuations in the received signal level is termed as fading.