Extension of the normalized two-ray transfer-function model to a space-diversity line-of-sight link

Many methods for the prediction of multipath effects on the availability of a digital microwave line-of-sight link use a mathematical and statistical modeling of the propagation channel transfer function. Such a method, making use of the normalized two-ray model and adapted to a nonprotected hop, has been presented in a previous paper. In this paper we investigate the possibility to extend this model to a diversity channel, while keeping the statistical representation of the channel as simple as possible. Two theoretical possibilities, each leading to only one new statistical coefficient, are presented and validated on experimental data. From this result, a simple extension of the availability prediction method to a diversity channel seems to be feasible. Some problems remain to be solved however, which are discussed in the concluding section