Joint Optimization for on-Demand Deployment of UAVs and Spectrum Allocation in UAVs-Assisted Communication

To improve the efficiency and fairness of the spectrum allocation for ground communica-tion assisted by unmanned aerial vehicles(UAVs),a joint optimization method for on-demand deployment and spectrum allocation of UAVs is proposed,which is modeled as a mixed-integer non-convex optimiza-tion problem(MINCOP).An algorithm to estimate the minimum number of required UAVs is firstly pro-posed based on the pre-estimation and simulated an-nealing.The MINCOP is then decomposed into three sub-problems based on the block coordinate descent method,including the spectrum allocation of UAVs,the association between UAVs and ground users,and the deployment of UAVs.Specifically,the optimal spectrum allocation is derived based on the interfer-ence mitigation and channel reuse.The association between UAVs and ground users is optimized based on local iterated optimization.A particle-based op-timization algorithm is proposed to resolve the sub-problem of the UAVs deployment.Simulation results show that the proposed method could effectively im-prove the minimum transmission rate of UAVs as well as user fairness of spectrum allocation.