Orbital Diversity in Resource-Shared Satellite Communication Systems Above 10 GHz

The paper discusses orbital diversity (OD) used as the common resource in a satellite communication adaptive system affected by rain attenuation. To give quantitative results, a simulation at 20/30 GHz is performed with a mathematical model; also, some experimental results are shown. OD performance for a single site is first discussed. Then the probabilistic theory for adaptive systems is built up and applied to the simulated system. System reconfigurability and switchover are discussed, considering only transfer medium propagation characteristics, without addressing the important overall economic aspects. The comparison to frequency diversity employed in the same system shows that OD may be competitive if it is used in conjunction with radio links with unequal power margins, and a low ratio (number of spare channels over number of assisted stations) is required.