Flight time minimization of UAV for cooperative data collection in probabilistic LoS channel

This paper investigates the data collection in an unmanned aerial vehicle(UAV)-aided Internet of Things(IoT)network,where a UAV is dispatched to collect data from ground sensors in a practical and ac-curate probabilistic line-of-sight(LoS)channel.Es-pecially,access points(APs)are introduced to col-lect data from some sensors in the unlicensed band to improve data collection efficiency.We formulate a mixed-integer non-convex optimization problem to minimize the UAV flight time by jointly designing the UAV 3D trajectory and sensors'scheduling,while en-suring the required amount of data can be collected under the limited UAV energy.To solve this non-convex problem,we recast the objective problem into a tractable form.Then,the problem is further divided into several sub-problems to solve iteratively,and the successive convex approximation(SCA)scheme is ap-plied to solve each non-convex subproblem.Finally,the bisection search is adopted to speed up the search-ing for the minimum UAV flight time.Simulation re-sults verify that the UAV flight time can be shortened by the proposed method effectively.