A Novel Energy-aware Design for a D2D Underlaid UAV-Aided Cognitive Radio Network

This paper investigates the effectiveness of a free disaster response network (free-DRN) and an energy harvesting enabled DRN (EH-enabled DRN) enhanced by cognitive radio (CR) technology and unmanned aerial vehicles (UAVs). In the EH-enabled DRN scenario, where device-to-device (D2D) communication harvests energy from cellular users, significant improvements are demonstrated in terms of energy efficiency (EE) and communication rate compared to the free-DRN approach. The impact of user density and UAV specifications on network performance is analyzed, addressing the challenge of optimizing the duration of energy harvesting for both cellular users and D2D devices in the EH-enabled DRN scenario. Additionally, simulation results reveal an optimal UAV height that ensures efficient network operation for varying densities of D2D devices. Overall, numerical and simulation findings highlight the superior performance of the EH-enabled DRN approach, showcasing the positive effects of enabling D2D links and improved EE. Notably, reducing energy harvesting duration and cellular user density can further enhance the EE of the DRN by up to 3dB.