Pair-Wise Hovering Location and Power Control for UAV-Assisted NOMA-Enabled Backscattering

As mobile networks increasingly support sustainable and green Internet of Things (IoT) applications, energy-efficient solutions that address coverage constraints have become paramount. Although backscatter communication (BSC) offers a low-power option for IoT devices, it can suffer from limited coverage. To overcome this, we leverage unmanned aerial vehicles (UAVs) and non-orthogonal multiple access (NOMA) to enhance both coverage and spectral efficiency. Motivated by vehicular communication applications, this paper investigates a NOMA-enabled UAV-assisted BSC framework to maximise system throughput by jointly optimising power allocation and trajectory scheduling. We derive a closed-form solution for the UAV's optimal collection location and apply the Karush-Kuhn-Tucker (KKT) conditions to obtain the power allocation. The numerical and simulation results demonstrate sum-throughput improvements of 620.278% and 7.795% compared to two benchmark schemes, underscoring the potential of our approach for large-scale IoT deployments.