Capacity Optimization of Spatial Preemptive Scheduling for Joint URLLC-eMBB Traffic in 5G New Radio

Ultra-reliable and low-latency communication (URLLC) is envisioned as a primary service class of the fifth generation mobile networks. URLLC applications demand stringent radio latency requirements of 1 millisecond with 99.999% confidence. Obviously, the coexistence of the URLLC services and enhanced mobile broadband (eMBB) applications on the same spectrum imposes a challenging scheduling problem. In this paper, we propose an enhanced spatial preemptive scheduling framework for URLLC-eMBB traffic coexistence. The proposed scheduler ensures an instant and interference-free signal subspace for critical URLLC transmissions, while achieving best-effort eMBB performance. Furthermore, the impacted eMBB capacity is then recovered by limited network-assisted signaling. The performance of the proposed scheduler is evaluated by highly detailed system level simulations of the major performance indicators. Compared to the state-of-the-art multi-traffic schedulers from industry and academia, the proposed scheduler meets the stringent URLLC latency requirements, while significantly improving the achievable ergodic capacity.