Energy-Efficient 3-D Deployment of Aerial Access Points in a UAV Communication System

In this letter, we propose an energy-efficient 3-dimensional placement of multiple aerial access points (AAPs), in the desired area, acting as flying base stations for uplink communication from a set of ground user equipment (UE). The globally optimal energy-efficient vertical position of AAPs is derived analytically by considering the inter-cell interference and AAP energy consumption. The horizontal position of AAPs, which maximize the packing density of the AAP coverage area, are determined using a novel regular polygon-based AAP placement algorithm. We also determine an accurate upper bound on the maximum number of AAPs that could be deployed in a given circular area. The effect of the AAP energy consumption on the optimal placement and the analytic findings are verified via numerical simulations.