  Recently, unmanned aerial vehicle (UAV) has attracted much attention due to
its flexible deployment and controllable mobility. As the general communication
network cannot meet the emergency requirements, in this paper we study the
multi-UAV enabled wireless emergency communication system. Our goal is to
maximize the capacity with jointly optimizing trajectory and allocating power.
To tackle this non-convex optimization problem, we first decompose it into two
sub-problems to optimize the trajectory and power allocation, respectively.
Then, we propose the successive convex approximation technique and the block
coordinate update algorithm to solve the two subproblems. The approximate
optimal solution can be obtained after continuous iterations. Simulation
results show that the capacity can be greatly increased using our proposed
joint trajectory optimization and power allocation.
