  In unmanned aerial vehicle (UAV)-assisted data collection system, UAVs can be
deployed to charge ground terminals (GTs) via wireless power transfer (WPT) and
collect data from them via wireless information transmission (WIT). In this
paper, we aim to minimize the time required by a UAV via jointly optimizing the
trajectory of the UAV and the transmission scheduling for all the GTs. This
problem is formulated as a mixed integer nonlinear programming (MINLP) which
are difficult to address in general. To this end, we develop an iterative
algorithm based on binary search and successive convex optimization (SCO) to
solve it. The simulation shows that our proposed solution outperforms the
benchmark algorithms.
