Hovering Localization and Power Allocation for UAV assisted DF Relaying
Ad Hoc Network
Abstract
An ad-hoc network using unmanned aerial vehicle (UAV) as relay, has been
gaining significant attention especially for communication between far
apart ground terminals during emergency conditions due to agility and
resilience requirements. However, UAV hovering localization (HL) and
power allocation (PA) are the key issues in such relay based flying ad
hoc networks (FANETs). In this work, we propose a framework to jointly
optimize the placement of rotary-wing UAV hovering and PA for
maximization of network throughput in a three node decode-and-forward
(DF) FANET. Specifically, we develop three different optimization
schemes, (i) individual UAV HL optimization with a fixed allocated
power, (ii) individual PA optimization for a fixed UAV HL, (iii) jointly
optimal UAV HL and PA. For every optimization problem, the underlying
convexity is proved and the global optimal solutions have been obtained.
Further, we provide novel analysis by utilizing the characteristics of
sigmoidal function thereby obtaining the closed-form and
semi-closed-form expressions respectively for the globally-optimal
solutions for individual and joint optimization schemes. The analytical
results are numerically validated and various optimal design insights
are discussed. It has been found that the proposed joint optimal scheme
shows an average performance enhancement of 52% over benchmark scheme.