Sum-Rate Maximization in Integrated Space-Air-Ground Networks under Backhaul Capacity Constraints

Integrated space-air-ground (ISAG) networks have emerged as a promising technology for next-generation commu-nication networks, which demand higher throughput and wider coverage. However, several challenges must be addressed, such as wireless resource and interference management, transmit power control, and optimal deployment of unmanned aerial vehicles (UAV s) to achieve higher throughput. To this end, in this paper, we propose the joint transmit power control and the deployment UAV problem in the ISAG network to maximize the sum-rate of devices while guaranteeing the minimum rate requirement of each device and the wireless backhaul link constraints between UAV s and the satellite. However, solving the resulting problem is challenging since it has a non-convex structure. As a solution, we propose to decompose the problem into two subproblems. We then transform the decomposed subproblems into convex forms and solve them using successive convex approximation (SCA). Finally, we conduct extensive simulations to show the effectiveness of the proposed method, and the numerical results show that the proposed method achieves a performance gain: up to 8.35%, and 4.08% in comparison to FPA and C-UAVs schemes.