Cooperative transmission for geostationary orbiting satellite collocation system

In order to improve the capacity and spectral efficiency of geostationary orbiting satellite collocation system, a cooperative transmission scheme is proposed in this paper. With the cooperative beamforming at the ground control station, a satellite spot beam can be split into virtual beams, which can support radio resources multiplexing for selected users. A cooperative gain is defined and further studied to evaluate the enhancement of cooperative and non-cooperative system. Then, according to this cooperative gain, a ground user selection criterion is derived, in which equivalent distance mismatch can be tolerated under the constraint of capacity degradation. Furthermore, the expectation of selectable ground users is analyzed to show the feasibility of our proposed scheme. Simulation results demonstrate that with the proposed cooperative transmission scheme, a high cooperative gain can be achieved.