Based on the Terminal Feedback PUR

This paper proposes a terminal-feedback-based pre-authorized uplink resource (PUR) scheduling scheme for NB-IoT systems to improve uplink radio resource utilization under massive machine-type communication scenarios. In the proposed approach, terminals provide lightweight feedback indicating the actual usage of allocated PUR resources, enabling the base station to promptly identify unused uplink grants and reclaim idle resources for subsequent scheduling. This mechanism reduces resource waste caused by empty packet transmissions and improves scheduling flexibility under dynamic traffic conditions. Furthermore, the proposed framework exploits the long-term channel stability of PUR terminals to support MU-MIMO transmission, thereby enhancing spectrum utilization and uplink capacity. Analytical modeling and simulation results demonstrate that the proposed method maintains high resource efficiency even under elevated empty-packet-rate conditions, where conventional PUR mechanisms suffer significant performance degradation. The scheme also enables more flexible resource reuse while introducing only limited signaling and power-consumption overhead. The results confirm that the proposed terminal-feedback strategy effectively improves uplink scheduling efficiency and spectrum utilization, providing a practical solution for large-scale NB-IoT deployments and industrial wireless communication systems.