Cooperative AF-based 3D Mobile UAV Relaying for Hybrid Satellite-Terrestrial Networks

Abstract

In this paper, we consider a hybrid satellite-terrestrial network (HSTN) where a multiantenna satellite communicates with a ground user equipment (UE) with the help of multiple amplify-and-forward (AF) three-dimensional (3D) mobile unmanned aerial vehicle (UAV) relays. Herein, we employ a stochastic mixed mobility (MM) model to deploy mobile UAV relays in a 3D cylindrical cell with UE at its ground centre. Taking into account the multiantenna satellite links and the random 3D distances between UAV relays and UE, we analyze the outage probability (OP) of considered system under an opportunistic UAV relay selection policy. We further carry out asymptotic OP analysis to present insights on system diversity order. Moreover, we compare the performance of proposed 3D mobile UAV relaying with the fixed altitude mobile UAV relaying as well as the fixed distance static relaying schemes. The analysis will be verified through simulations.