Outage Performance of Multi-UAV Relaying-Based Imperfect Hardware Hybrid Satellite-Terrestrial Networks

In this paper, we consider an imperfect hardware hybrid satellite-terrestrial network, where the satellite communication with a ground user equipment (UE) is aided by the multiple amplify-and-forward 3-D mobile unmanned aerial vehicle (UAV) relays. Herein, we consider that all transceiver nodes are corrupted by the radio frequency hardware impairments (RFHI). Furthermore, a stochastic mixed mobility model is employed to characterize the instantaneous location of 3-D mobile UAV relays in a cylindrical cell with UE lying at its center on the ground plane. Taking into account the aggregate RFHI model for satellite and UAV relay transceivers and the random 3-D distance-based path loss for UAV relay–UE links, we investigate the outage probability and corresponding asymptotic outage behavior of the system under an opportunistic relay selection scheme in a unified form for shadowed-Rician satellite links’ channels and Nakagami-
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as well as Rician terrestrial links’ channels. We corroborate theoretical analysis by simulations.