Joint Precoding and User Scheduling for Full-Duplex Cooperative MIMO-NOMA V2X Networks

In this paper, an urban vehicular communication network with densely distributed users is considered. To improve the system's average spectral efficiency, non-orthogonal multiple access (NOMA) and device-to-device-aided full-duplex cooperative communication are applied into V2X networks. First, we prove that such a system suffers from unfair spectrum efficiency between cell-center users (CCUs) and cell-edge users (CEUs). To handle this challenge, we propose a fair precoding scheme, which utilizes the centroid of users' channel vectors to calculate the precoding vectors. Then, a novel joint precoding and user scheduling strategy called JPUS is proposed. This strategy enables the CCUs to serve the CEUs without changing the order of successive interference cancellation receiving. Finally, a crossroad traffic model generated by cellular automaton is exploited, and simulation results show that the proposed scheme achieves higher spectral efficiency compared with conventional NOMA schemes, typical cooperative NOMA schemes and half-duplex JPUS schemes.