Access-rate-centric resource allocation and sum-rate optimization under QoS constraints in dense V2V networks

Sum-rate-driven optimization often allocates surplus rate to a limited number of favorable links, thereby consuming shared resources that could otherwise support additional users at their required quality-of-service (QoS) levels. This observation motivates access-oriented designs that prioritize admitting more users before refining throughput. To this end, we propose a two-stage framework that first enhances access rate under explicit QoS guarantees and subsequently optimizes sum-rate. In the first stage, a many-to-many channel allocation mechanism based on analytically derived feasibility conditions admits the maximum number of vehicular pairs while satisfying their minimum data-rate requirements. In the second stage, transmit powers are refined through a Stackelberg game with multi-start initialization and periodic feasibility repair, enabling spectral-efficiency enhancement without violating QoS constraints. By expanding feasible channel reuse, the proposed approach simultaneously improves user accessibility and unlocks additional sum-rate gains. Simulation results demonstrate substantial improvements in both access rate and throughput compared with conventional sum-rate–oriented methods.