More on the Multipath Fading Channel Model

Selective fading due to muitipath on a typical narrowband line-of-sight microwave radio path is represented with a simplified three-ray model. This model provides a satisfactory description of the frequency transfer characteristics of almost all fades observed during three separate propagation experiments. Data were obtained for a 30 MHz bandwidth at 6 GHz using both a standard horn reflector and a parabolic dish, and for a 20 MHz bandwidth at 4 GHz using the horn. The statistics of the parameters of the model were found to be substantially the same for all three cases. The incidence of selective fading scales, within a factor of two, with the incidence of fading at a single frequency, for 1-month observation intervals.