Optimizing Dynamic Spectrum Sharing in UAV-Assisted Networks: Hybrid Two-Stage Stackelberg Game Approach

In the 5G era, the demand for high-quality communication services has rendered spectrum resources increasingly scarce, particularly for remote users (UEs). Unmanned Aerial Vehicles (UAVs) provide a viable solution to this challenge by facilitating dynamic spectrum sharing. This paper proposes a hybrid two-stage Stackelberg game model that enhances UAV-assisted communications by integrating both static and dynamic spectrum-sharing strategies. In this model, UAVs serve as relays for base stations (BSs) to serve remote UEs. They can optimize spectrum allocation and negotiate pricing directly with UEs instead of BS, thereby reducing the burden on BS. The model operates in two stages: In the first stage, UAVs act as followers with BS as leaders; In the second stage, UAVs become leaders in interactions with remote UEs. Our analysis focuses on the effects of spectrum sharing and pricing strategies on system performance, emphasizing the enhanced utility for BS, UAVs, and UEs. We demonstrate that the proposed model significantly improves spectrum efficiency, particularly under high-demand conditions, and maintains stable and efficient operations within UAV-assisted communication systems, as supported by simulation results.