Performance improvement of satellite/terrestrial integrated mobile communication system using unmanned aerial vehicle cooperative communications

A satellite/terrestrial integrated mobile communication system (STICS), in which the satellite system and terrestrial system share the same frequency band, enables user terminals to access both systems. The STICS is expected to play an important role as a communication infrastructure in times of natural disasters, and as a means of communication in mountainous and oceanic regions, where a terrestrial station does not exist. However, in STICSs, since both systems use the same frequency band, the communication quality of the satellite link is degraded by the interference from terrestrial communication links. Therefore, to improve the quality of the satellite downlink, we propose a cooperative communication scheme using two timeslots with unmanned aerial vehicles (UAV) acting as relay stations. The effectiveness of the scheme is demonstrated by numerical simulations.