Research on Optimal Energy Efficient Power Allocation for NOMA System in High-Speed Railway Scenarios

This paper mainly studies the application of non-orthogonal mutiple access (NOMA) technology in wireless communication systems in high-speed rail scenarios to solve the uplink energy efficiency of NOMA systems. User's quality of service (QoS) and maximum transmit power constraints are considered, the objective function is constructed as an optimization model to maximize energy efficiency. Based on fractional programming, the energy efficiency maximization problem is converted to a series of subtractive subproblems. The problem is solved by Lagrange dual method, and the Lagrange dual variables are updated using the sub gradient method, a low-complexity optimal power allocation scheme based on the Dinkelbach method is proposed. The simulation results show that under the constraints of the same maximum transmit power and QoS requirements, the NOMA system can always obtain better energy efficiency performance than the traditional orthogonal multiple access (OMA).