Energy-Efficiency Maximization for D2D-Enabled UAV-Aided 5G Networks

Abstract

<p>Reliable and flexible emergency communication is<br> a crucial challenge for search and rescue in the circumstance<br> of disasters, specifically for the situation when base stations<br> (BS) are no longer functioning. Unmanned aerial vehicle (UAV)-<br> aided networking is becoming a prominent solution to establish<br> emergency networks with the underlay device-to-device (D2D),<br> which also should be energy-efficient. In this article, we study<br> energy-efficiency (EE) maximization for interference-aware underlay<br> D2D-enabled UAV-aided 5G systems. All the interference<br> scenarios are taken into account while modeling the system<br> architecture. Afterward, we formulate an objective function to<br> optimize EE maximization, which shows the characteristic of an<br> NP-hard nonconvex research problem. Therefore, we transform<br> the nonconvex problem into a convex one by reformulating the<br> constraint functions with the cubic inequality method. Several<br> criteria are developed to satisfy the non-negativity of the reformulating<br> constraint. This leads the problem to be solved as a<br> convex optimization method and results in an efficient iterative<br> resource allocation algorithm. In each iteration, the transformed<br> problem is solved by using Lagrangian dual decomposition<br> with a projected gradient method. In the end, we analyze the<br> convergence behavior of the studied algorithm and also compared<br> it with another existing algorithm through numerical simulations.</p>