Non-orthogonal multiple access (NOMA) and backscatter communications are considered to be promising technologies for beyond the fifth-generation (5G) due to their applications in large-scale Internet-of-things networks for providing low-powered and spectral-efficient communication. NOMA also provides a new way to enable vehicle-to-everything (V2X) networks and improve the achievable rates through cooperation. Motivated by these developments, we provided a novel analysis for NOMA-enabled backscatter-based V2X networks. Specifically, we consider that several vehicles are connected to the base station (BS) via different roadside units (RSUs) and the backscatter tags along the road. These backscatter tags can be considered ultra low-powered safety sensors that communicate with the vehicles using the same spectrum resources. To optimize the performance of such networks, a joint problem of optimal power allocation at BS and RSUs has been formulated. Subsequently, the problem has been transformed into a convex problem and solved using KKT conditions and subgradient methods. To evaluate the performance of the proposed solution, Monte-Carlo simulations have been performed in MATLAB. The acquired results clearly demonstrate that the proposed approach performs better than the conventional suboptimal NOMA scheme and joint optimal TDMA scheme.
- Backscatter communication
- non-orthogonal multiple access
- power allocation