  In this paper, we consider an unmanned aerial vehicle (UAV)-enabled emergency
communication system, which establishes temporary communication link with users
equipment (UEs) in a typical disaster environment with mountainous forest and
obstacles. Towards this end, a joint deployment, power allocation, and user
association optimization problem is formulated to maximize the total
transmission rate, while considering the demand of each UE and the disaster
environment characteristics. Then, an alternating optimization algorithm is
proposed by integrating coalition game and virtual force approach which
captures the impact of the demand priority of UEs and the obstacles to the
flight path and consumed power. Simulation results demonstrate that the
computation time consumed by our proposed algorithm is only $5.6\%$ of the
traditional heuristic algorithms, which validates its effectiveness in disaster
scenarios.
