A cooperative MEC framework based on multi-UAV and AP to minimize weighted energy consumption

In this paper, a cooperative MEC system with multi-UAV and a ground access point (AP) is considered, in which UAVs can act as both a computing platform to help Internet of Things devices (IoTDs) deal with their computing tasks and a relay platform to offload some of the task data from IoTDs to the AP with higher computing ability. We aim to minimize the weighted overall energy consumption of UAVs and IoTDs by jointly optimizing connection scheduling, CPU frequency, task offloading bits and the flight trajectory of UAVs. The formulated problem is a Mixed-Integer Nonlinear Programming (MINLP) problem, which is hard to solve. To tackle this problem, we divided it into three sub-problems and resolved them iteratively by the Lagrangian dual method and succession convex approximation (SCA) technique. Finally, an alternately iterative optimization algorithm is proposed. The numerical results show that our proposed algorithm has better performance compared to other benchmark algorithms.