Performance Evaluation of Relaying with Different Relay Selection Schemes in 5G NR V2X Communications

This paper presents the performance of relay selection schemes in 5G New Radio (NR) network. The 5G NR is anticipated to enable reliable vehicular networking, with emphasis on Vehicle-to-Everything (V2X) communications. Here, 5G NR is required to support V2X Side Link (SL) communications for C-Plane signaling via wireless Uu interface, which naturally suffers from fading and path loss. Therefore, relaying can address this concern by deploying a low power relay node (RN) in 5G NR network. This paper presents the end-to-end (e2e) performance of dual-hop relaying under four different relay selection schemes and different RN density/deployment scenarios. These selection schemes comprised of the combinations of average and/or instantaneous wireless channel conditions of the two links involved in the transmission, wireless backhaul relay link (RL) and access link (AL). Simulation results demonstrate that when relay selection is performed relying on the instantaneous e2e link conditions, the best performance in terms of average e2e data rate can be obtained. Moreover, higher RN density in network, yields enhanced performance, due to the availability of additional paths to select from, especially, when RNs are randomly deployed rather than at fixed locations.