In this paper, we consider a heterogeneous repository of drone-enabled aerial base stations with varying transmit powers that provide downlink wireless coverage for ground users. One particular challenge is optimal selection and deployment of a subset of available drone base stations (DBSs) to satisfy the downlink data rate requirements while minimizing the overall power consumption. In order to address this challenge, we formulate an optimization problem to select the best subset of available DBSs so as to guarantee wireless coverage with some acceptable transmission rate in the downlink path. In addition to the selection of DBSs, we determine their 3D position so as to minimize their overall power consumption. Moreover, assuming that the DBSs operate in the same frequency band, we develop a novel and computationally efficient beamforming method to alleviate the inter-cell interference impact on the downlink. We propose a Kalai-Smorodinsky bargaining solution to determine the optimal beamforming strategy in the downlink path to compensate for the impairment caused by the interference. Simulation results demonstrate the effectiveness of the proposed solution and provide valuable insights into the performance of the heterogeneous drone-based small cell networks.

翻译：本文研究了一组具有不同发射功率的无人机空中基站异构库，其可为地面用户提供下行无线覆盖。一个特别挑战在于如何从可用的无人机基站（DBS）子集中进行最优选取与部署，在最小化总功耗的同时满足下行数据速率需求。为解决该问题，我们构建了一个优化问题，以选取最优的可用DBS子集，从而在下行路径中保证具有可接受传输速率的无线覆盖。除DBS选择外，我们确定其三维位置以最小化总功耗。此外，假设DBS在同一频段运行，我们提出了一种新颖且计算高效的波束成形方法，以减轻小区间干扰对下行链路的影响。我们采用Kalai-Smorodinsky讨价还价解来确定下行路径中的最优波束成形策略，以补偿干扰造成的损伤。仿真结果验证了所提方案的有效性，并为异构无人机小蜂窝网络的性能提供了有价值的见解。