Exploiting Repetitions and Interference Cancellation for the 6G-V2X Sidelink Autonomous Mode

TL;DR

This paper introduces a novel interference cancellation method for 6G-V2X sidelink communications, leveraging repeated packets and SIC to improve reliability and reduce collisions in autonomous vehicle networks.

Contribution

It proposes using SIC at receivers to exploit packet repetitions, significantly enhancing Mode 2 performance under high interference conditions.

Findings

Over 100% performance improvement in highway scenarios

Effective interference mitigation with packet repetitions and SIC

Enhanced reliability in autonomous vehicle communications

Abstract

In recent years, the Third Generation Partnership Project (3GPP) has developed the new radio-vehicle-to-everything (NR-V2X) sidelink standard, to enable direct communication between connected and autonomous vehicles (CAVs). Users can autonomously select radio resources for their transmissions with the Mode 2 channel access scheme, which can also operate under out-of-coverage conditions. However, Mode 2 performance is hindered by interference and packet collisions arising from dynamic mobile environments and limitations in assessing radio resource availability. The 3GPP specifications allow transmitting multiple copies of the same packet to improve reliability, though at the cost of increased channel congestion. This paper proposes to leverage receivers equipped with successive interference cancellation (SIC) capabilities, to exploit packet repetitions. Specifically, once a packet is successfully decoded the interfering contribution carried by repetitions can be cancelled from future or past received signals, enabling the decoding of new packets. Extensive highway scenario simulations demonstrate that the proposed solution significantly outperforms the legacy Mode 2 scheme, especially under high interference conditions, achieving improvements exceeding 100% in some cases.