Energy-Efficient Spectrum Allocation and Deployment Scheme for UAV Emergency Communications

Unmanned aerial vehicle (UAV) can serve as aerial base station to quickly restore the communication coverage of the disaster area, but finite energy poses a crucial challenge to UAV emergency communications. To maximize the average energy efficiency of UAV emergency communications, we propose the energy-efficient spectrum allocation and deployment (ESAD) scheme, which covers all disaster users and guarantees the quality of service (QoS) for users by deploying multiple UAVs. Based on the QoS requirement of user and graph coloring method, we propose the interference avoidance algorithm, which avoids interference among users served by the same UAV and interference among UAVs through user spectrum resource allocation and UAV spectrum management, respectively. Then, the ESAD scheme is proposed to achieve the maximum average energy efficiency of UAV while covering all disaster users. Simulation results show that compared with traditional schemes, the proposed scheme effectively reduces the number of deployed UAVs and improves the average energy efficiency of UAV emergency communications.