Downlink Coverage Performance Analysis of UAV Assisted Terrestrial Cellular Networks

In this paper, we consider a downlink communication system where unmanned aerial vehicle base stations (UBSs) assisted ground base stations (GBSs) to provide service, in which both the UBSs and the GBSs follow the independent Poison point process distributions. The air-to-ground channel model is adopted to describe the channel characteristic of UBS to the user equipment. We provide exact expressions for the association probabilities with the UBS/GBS. By applying stochastic geometry method, we derive the explicit expression of overall coverage probability. The simulation results show that the effect of UAV height on coverage probability is not linear. The flight altitude needs to be adjusted according to the base station deployment density to maximize overall coverage.