Power and Element Allocation Design for RIS-NOMA IoV Networks

In this paper, a cooperative, non-orthogonal multiple access (NOMA)-based internet of vehicles (IoV) network is proposed, which is assisted by a reconfigurable intelligent surface (RIS) to enhance signal transmission. Due to the intelligent control of RISs, the channel condition of our proposed IoV system is more diversified compared to conventional NOMA-RIS schemes, and thus two power allocation schemes are considered to tackle this issue, providing better channel gain to transmit signals. In this proposed scheme, power allocation schemes are discussed for a diverse number of reflecting elements, and a number of elements are obtained serving users near or far. To further improve system capacity and guarantee quality of service (QoS), we derive the number of elements to guarantee the same transmission data sum-rate under different channel qualities. Numerical and simulation results verify the correctness as well as superiority of our proposed scheme.