Joint Resource Scheduling And Trajectory Planning For Multi-UAV Assisted Cooperative Transmission In Marine Environment Monitoring

With the rapid deployment of information and communication technologies,the emerging Internet of Things(Io T)system has a wide range of applications in the smart ocean.In the marine Internet of Things system,many Unmanned Surface Vehicles(USV)are deployed to monitor the marine environment in a collaborative manner.In addition,multiple USVs transmit sensor data to onshore base stations(OBS)through wireless channels to monitor the marine environment.Due to limited transmission power,large transmission distance,and complicated maritime wireless environment,the transmission throughput and transmission reliability of monitoring data cannot be guaranteed,which leads to a decrease in the performance of marine environment monitoring.In order to improve the transmission rate of marine environment monitoring information,we first study a method of using multiple Unmanned Aerial Vehicles(UAV)as a fixed aerial relay node for auxiliary cooperative transmission.Maximize the total throughput under the constraints of the channel.Specifically,we analyze the achievable transmission reliability of the USV-OBS link,because marine environment monitoring applications have certain requirements for the probability of interruption.Then,we optimize the total transmission throughput under the interruption probability requirement by jointly optimizing the USV-UAV correlation and transmit power control.Finally,a Heuristic Algorithm(HA)is designed to effectively solve the 0-1 integer programming problem.The simulation results show that the proposed heuristic algorithm can obtain near-optimal solutions with lower computational complexity.In order to further improve the transmission rate of the maritime wireless channel,we study a method of cooperative transmission of multiple drones as mobile aerial information collection nodes,and propose a fast UAV trajectory planning based on the Fermat point theory Algorithm to improve the overall data collection rate of all USVs.Specifically,we build the Delaunay triangle based on the deployment location of the USV.Then,the Fermat point of each Delaunay triangle is calculated as the hovering point of the UAV to improve the channel conditions.Finally,the trajectory planning problem can be transformed into the vehicle routing problem with pick-up.This problem is solved by the proposed algorithm based on the C-W method(Clarke G,Wright J W,1964).The results show that the algorithm can improve the data collection rate and the amount of collected data,while reducing the UAV flight energy consumption and computational complexity.