Degradation of the carrier-to-interference ratio (C/I) of an Earth-space system using frequency re-use due to interference induced by an adjacent dual polarized satellite system

The increasing demand for satellite communication channels has caused system designers to implement frequency re-use techniques. For frequencies above 10 GHz which are of high importance in current satellite systems the main propagation effects on interference between adjacent Earth-space systems are considered to be the differential rain attenuation and the cross-polarization. A predictive method is presented considering the case when a single-site dual polarized system is being interfered by an adjacent system which is also operating under the dual polarization mode at the same frequency. The method is based on a model of convective rain cells for the rainfall medium as well as the assumption that the point rainfall statistics follows a lognormal distribution. Numerical results are presented referring to communication systems operating all over the world, suffering from differential rain attenuation and cross-polarization. Special emphasis is given to the results concerning coordination studies and the efficient utilization of the geostationary orbit. Some useful conclusions are deduced.