Optimal Deployment of Base Stations in Cognitive Satellite-Terrestrial Networks

We investigate the performance of a downlink multi- beam cognitive satellite terrestrial network (CSTN) in which a secondary network (mobile terrestrial system) shares resources with a primary satellite network given that the interference temperature constraint is satisfied. Utilising tools from stochastic geometry, we derive the closed-form optimal density of base stations subject to interference temperature and outage proba- bility constraints set by satellite system. In addition, the gains of directional beamforming are analysed when the terrestrial system employs multiple-input-multiple-output (MIMO) transceivers or by the use of millimeter wave links between terrestrial BSs and users.