QoS Aware User Association and Transmission Scheduling in Heterogeneous Space-Air-Ground Integrated Networks

With the development of 6G and beyond, space-air-ground integrated networks (SAGINs) have become a key factor in promoting high-speed seamless connectivity for users. In this paper, we studied a heterogeneous SAGIN in the millimeter wave (mmWave) band, which comprises unmanned aerial vehicles (UAVs), high-altitude platforms (HAPs), and low earth orbit satellite as aerial base stations (ABSs) in a scenario featuring partial damage to ground base stations (GBSs). Under the constraint of limited system power resources, we optimize the deployment of ABSs and the association and scheduling of users. We formulate a mixed-integer nonlinear programming (MINLP) problem aimed at maximizing the scheduling of users with quality of service (QoS) requirements and propose a block coordinate descent (BCD) based sequential quadratic programming-minimum rate ratio (SQP-MQR) algorithm to solve this problem. Simulation results demonstrate the superiority of our proposed algorithm in scheduling users with QoS requirements compared to other selected schemes in the heterogeneous SAGIN.