Joint association and power optimization for multi-UAV assisted cooperative transmission in marine IoT networks

With the rapid deployment of information communication technologies, the emerging Internet of Things (IoT) system has a wide range of applications in smart ocean. In the marine IoT system, many unmanned surface vehicles (USVs) are deployed to monitor the marine environment in a coordinated manner. Moreover, multiple USVs cooperatively transmit the sensory data via wireless channels to the onshore base station (OBS) for estimating the marine environment. Due to the limited transmit power, large transmission distance, complex maritime wireless environment, the transmission throughput and transmission reliability of sensory data could not be guaranteed, which will deteriorate the environment monitoring performance. In order to solve this problem, this paper investigates a multi-UAV assisted cooperative transmission to maximize the total throughput under the constrained of outage probability, transmit power and available channels. In particular, we firstly analyze the achievable transmission reliability of the USV-OBS link, since the marine environment monitoring application has a certain requirement for the outage probability. Then, we optimize the total transmission throughput under the requirement of outage probability by jointly optimizing the USV-UAV association and the transmit power control. Finally, a heuristic algorithm is designed to effectively and efficiently solve the 0 - 1 integer programming problem. Simulation results show that the proposed heuristic algorithm could obtain the near-optimal solution with low computational complexity.