Enhanced Distributed Resource Selection and Power Control for High Frequency NR V2X Sidelink

The 3GPP has standardized the 5G New Radio (NR) sidelink (SL) technology that enables direct device-to-device communications. SL will be key in realizing several high-speed, low-latency vehicle-to-everything (V2X) applications, such as automated driving. To meet these applications' high data rate requirements, operating SL at mmWave and sub-THz frequencies will be essential. However, the current SL design primarily caters to sub-6 GHz frequencies and does not consider the directionality of transmissions at high frequencies. For Mode 2 of SL, where SL UEs perform sensing-based autonomous resource selection, this results in hidden node interference due to the transmit (Tx) UE's inability to sense transmissions not aligned with the primary direction of communication. We propose paired transmission and sensing of sidelink control information (SCI), whereby SL Tx UEs transmit and receive SCI in an additional paired direction directly opposite to the primary direction. This helps eliminate hidden node interference while reducing the number of exposed nodes. Simulations in NR V2X highway deployments show that the paired scheme improves the average packet reception ratio (PRR) by 27% over the state-of-the-art at the highest traffic loads. We also propose enhanced transmit power control strategies to minimize interference between concurrent SL transmissions. This enables better resource reuse and further improves performance, with our combined solution achieving at least 95% average PRR in all scenarios. Finally, we present a stochastic geometry-based analytical model for a single-lane highway V2X network and validate it against simulation results. Our model provides insights into the reliability and capacity of high-frequency SL networks.

Automated summary

The 3GPP has standardized the 5G New Radio (NR) sidelink (SL) technology for direct device-to-device communications. To meet high data rate requirements, operating SL at mmWave and sub-THz frequencies is essential. However, the current SL design does not consider the directionality of transmissions at high frequencies, resulting in hidden node interference. The proposed paired transmission and sensing scheme improves the packet reception ratio by 27% and enhances performance in highway V2X deployments.