Optimal resource allocation for unmanned aerial vehicle- assisted wireless communications

In particular, Chapter 3 looks at a spectrum-sharing cognitive radio network where the UAVs are deployed as flying base stations to provide network coverage to the secondary network in a disaster area. A learning-aided optimisation scheme is designed to allocate radio resources under the constraints of maximum tolerable interference. Chapter 4 considers integrating reconfigurable intelligent surfaces onboard the UAVs to extend network coverage in a massive multiple-input multiple-output system.

The joint problem of optimal power allocation and phase-shift is solved, subject to deployment strategy and minimum data throughput. Finally, in Chapter 5, the UAVs assist in content caching in an integrated terrestrial-non terrestrial network. The joint optimisation problem of user clustering, cache placement, and power allocation is solved efficiently by using a distributed approach.

In all these cases, low-complexity algorithms are proposed and their usefulness is confirmed through simulation.