Mitigating Collisions in Sidelink NR V2X: A Study on Cooperative Resource Allocation

New Radio (NR) Vehicle-to-Everything (V2X) Sidelink (SL), an integral part of the 5G NR standard, is expected to revolutionize the automotive and rail industries by enabling direct and low-latency exchange of critical information between traffic participants independently of cellular networks. However, this advancement depends primarily on efficient SL resource allocation. Mode 2(a) is a well-known method for this purpose, where each node autonomously selects resources. However, this method is prone to packet collisions due to the hidden-node problem. In this paper, we propose a cooperative scheduling method that could potentially address this issue. We describe an extension of Mode 2(a) that allows nodes to share resource allocation information at two hops. Initial simulation results show a promising improvement over Mode 2(a).