Maximum Sum Rate of MCM–NOMA in Future Vehicular Sensor Networks

This letter addresses the challenge of determining the maximum sum rate achievable in high-mobility scenarios with time and frequency selectivity in 5G V2X communications, particularly in the context of Internet of Things (IoT)/sensor networks. We derive a closed-form expression for the maximum sum rate of a multicarrier nonorthogonal multiple access (NOMA) system with $n$ users and validate our theoretical results through simulations by comparing them with traditional orthogonal schemes. Our work provides valuable insights into the potential of NOMA for high-speed V2X communications, and offers a novel contribution to the existing literature by presenting a closed-form expression allowing the development of efficient and reliable 5G V2X systems.