Tradeoff between co-polar fading and cross-polar interference in earth station design for satellite communications

The orthogonal polarization techniques will be widely used in satellite communications due to its efficient utilization of the spectrum, but these techniques introduce an extra effect, the cross-polarization interference, which directly characterizes the transmission quality in addition to the conventional fading effect. Therefore, the propagation effects on the system performance become twofold: the co-polar fading on one hand and the cross-polar interference on the other hand. Inappropriate assignment of the margins of these two effects can increase the system cost tremendously without improving signal quality. In this paper, an earth station design method is developed which can properly choose the required CNR and XPD values and obtain a minimum-cost design based on the tradeoff between these two effects. A typical example is used to illustrate the applicability.