System Performance of Cooperative NOMA V2X Network Under Nakagami-m Fading Channel

Abstract

This study investigates a cooperative non-orthogonal multiple access (NOMA) scheme in Vehicle-to-Everything (V2X) network under the Nakagami-m fading channel. Specifically, a multi-antenna road site unit (RSU) communicates with two single-antenna vehicle units (VUs) using downlink non-orthogonal multiple access (NOMA) technique. Furthermore, the near VU can assist in relaying information to the far VU in imperfect channel states and imperfect decoding. We propose two operating protocols for the system based on the RSU’s transmit antenna selection. Accordingly, we present two lemmas describing the closed-form expression of the outage probability of two VUs. Finally, we investigate the performance of VUs according to the system parameters such as transmit power, power allocation coefficient, channel fading factor, imperfect factors. The numerical simulation results are entirely consistent with the theoretical calculations, proving the correctness of our study.