Resource Scheduling for eMBB and URLLC Multiplexing in NOMA-Based VANETs: A Dual Time-Scale Approach

Enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC) are two critical services in vehicular networks. However, the presence of both services creates a difficult resource allocation problem due to their heterogeneous requirements. To address the challenge of simultaneously providing eMBB and URLLC services in vehicular networks, we propose a resource allocation approach that maximizes eMBB rate while ensuring that both URLLC latency and reliability requirements are satisfied. Our approach utilizes non-orthogonal multiple access (NOMA) technology, where the resource for eMBB services is allocated by slot and the traffic of URLLC service is accommodated using mini-slots. To solve this dual time-scale problem, we employ a dual decomposition and sub-gradient method to solve the power allocation and resource block assignment of eMBB services, while the Vogel's approximation method (VAM) and modified distribution method (MODI) are proposed to solve the URLLC resource allocation problem. Additionally, we present two low-complexity heuristic algorithms for the URLLC sub-problem. Simulation results indicate that our proposed approach surpasses baseline methods in terms of both eMBB rate and fairness.