Applying NOMA to NR V2X: A Graph-based Matching and Cooperative Game Approach

Abstract

The application of Non-Orthogonal Multiple Access (NOMA) technology to New Radio (NR) V2X can further reduce communication delay and improve the system capacity of the vehicular network. However, in NR V2X Mode 1, the base station first needs to allocate resources in each transmission period, and then the vehicles transmit information by the allocated resource. According to this, we propose a two-stage scheme of centralized resource allocation and distributed power control to meet the requirement of the NR V2X Mode 1 while NOMA technology is employed in vehicle groups. Firstly, at the beginning of a transmission period, the base station allocates resources to vehicle groups. For this centralized manner, we propose a graph-based matching approach to allocate resources to improve system capacity. Then, each vehicle group controls and adjusts transmission power for NOMA communication in the period. For this distributed manner, we put forward a cooperative game approach to control the power of the vehicle group while increase system capacity. Simulation results show that the proposed scheme can increase the system capacity.