Conditional relay selection strategy based on V2X-NOMA cooperative network

In this paper, we study the vehicle-to-everything (V2X) cooperative relay non-orthogonal multiple access (NOMA) network system. The transmission of the signal is to send the information containing the target vehicle to the roadside unit (RSU) through the base station (BS), and the RSU then forwards this information to the target vehicle through decode-and-forward (DF). In order to improve transmission reliability, a conditional relay selection strategy is proposed to optimize the outage performance of the system. Through the performance analysis of each node, the expression of the signal-tonoise ratio (SNR) at different nodes and the closing expression of the final outage probability are derived, and then the influence of different numbers of relays and different transmit power on the outage performance of the system is analyzed by modeling. Finally, the simulation results are compared with other strategies to verify that the proposed strategy has an obvious improvement on outage performance and illustrate the applicability of the strategy.