Modeling and Coverage Analysis for Cellular-Connected UAVs With Up-Tilted Antenna

Abstract

Existing cellular network is designed mainly for terrestrial users (TUs) with down-tilted antennas, which couldn’t provide efficient 3D coverage for UAV users. This letter proposes up-tilted antenna model to provide 3D seamless coverage for cellular-connected UAVs, and derives coverage probability for both aerial users (AUs) and TUs via stochastic geometry, where the mutual interference between up-tilted and down-tilted antennas is characterized. Specifically, practical antenna model with tunable half power beamwidth <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta _{k}$ </tex-math></inline-formula> is adopted and power constraint between up-tilted and down-tilted antenna is considered by modelling power allocation parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> , where the interference Laplace transform is rederived considering the mutual interference. In addition, the theoretical analysis is based on semi-closed expression of coverage probability, which can be used to explore the impact of various system parameters. Numerical results show that when 10% of the power is allocated to up-tilted antenna ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha =0.9$ </tex-math></inline-formula> ), coverage probability of AUs can be significantly increased by 192%, while coverage probability of TUs reduced by less than 1%, compared with only down-tilted antenna.