Joint Trajectory Planning and Communication Design for Multiple UAVs in Intelligent Collaborative Air-Ground Communication Systems

In the space-air-ground integrated emergency communication network, unmanned aerial vehicles (UAVs) have become ideal candidates for expanding traditional base stations through the air-ground line of sight (LoS) link, providing more comprehensive and efficient support for emergency communication. To ensure timely information transmission among all ground users (GUs) involved in rescue, utilizing fair communication can reduce communication conflicts caused by resource competition and ensure that GUs can obtain necessary communication resources to improve rescue efficiency. Therefore, this article investigates the joint optimization of trajectory planning and communication design of multiple UAV base stations (UAV-BSs), as well as access control of GUs in intelligent collaborative air-ground communication systems. The optimization problem is modeled as a hybrid cooperative competition model, where GUs compete for limited UAV-BS resources to maximize their own long-term throughput, while UAV-BSs collaborate to provide maximum fair throughput for GUs in need. This model belongs to heterogeneous agent collaboration, where the goals of GUs and UAV-BSs are inconsistent, and the UAV-BS has inconsistent goals at different stages with or without GU requests. Therefore, a trajectory planning and communication design in intelligent collaborative air-ground communication (TPCD-ICAGC) algorithm is designed. By introducing a multi-head attention mechanism to quickly determine the target correlation with other agents in a complex state space, so as to improve the adaptability of agents to the model and make more effective decisions. The simulation results show that TPCD-ICAGC outperforms other benchmark algorithms in terms of fair communication services of UAV-BSs and accumulative throughput of GUs.