Centralized Resource Allocation and Distributed Power Control for NOMA-Integrated NR V2X

Abstract

The application of nonorthogonal multiple access (NOMA) technology to New Radio (NR) Vehicles-to-Everything (V2X) can further reduce communication delay and improve the system capacity of the vehicular network. However, due to the high mobility of the vehicles, it is difficult for the base station to obtain the channel information between vehicles in real time for resource allocation and vehicle transmission power control. To this end, we propose a two-stage scheme of centralized resource allocation and distributed power control to meet the NR V2X Mode 1 requirement while NOMA technology is employed in each vehicle group. First, 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 propose a noncooperative game to control the power of the vehicle groups and then analyze the performance of the noncooperative game. Afterward, we further put forward a cooperative game approach to control the power of the vehicle group to increase system capacity. Compared with the noncooperative game, the proposed scheme can increase communication capacity by up to 5% and reduce transmission power consumption by 36%.