Numerology-Persistence Coupling Performance in 5G NR-V2X Sidelink Communication

The impact of numerology selection on 5G New Radio (NR) Vehicle-to-Everything (V2X) sidelink communications, particularly its coupling with persistence mechanisms like Semi-Persistent Scheduling (SPS), has been insufficiently explored. This paper investigates how numerology-persistence coupling affects Age of Information (AoI) and system performance in sub-6 GHz NR-V2X deployments. Our analysis shows that at low-to-moderate vehicle densities, the performance differences across numerologies are minimal. However, under high channel load, numerology selection plays a key role in performance, with higher numerologies leading to increased collisions and reduced resource availability, which degrade performance. The results emphasize the importance of evaluating numerology in a cross-layer context (PHY and MAC layers), where lower numerologies tend to offer better performance, particularly in high-density environments, by providing a larger resource pool and reducing collisions.