A Low-Complexity Power Allocation Algorithm to Maximize Energy Efficiency in Uplink HSR Communications

In order to promote the green communication and improve the energy efficiency (EE) of high-speed railway (HSR) communications, we propose a low-complexity power allocation algorithm to maximize the EE for uplink HSR communications in this paper. Firstly, we formulate a non-convex optimization problem and convert it into an equivalent convex form. Then, the optimization problem is solved by Lagrange method. Finally, we analyze the feasible regions of the optimal solutions and propose a low-complexity algorithm to obtain the optimal power allocation while satisfying the buffer size. Simulation results show that the low-complexity algorithm can reduce the computation complexity largely and achieve the same EE performance as the bisection algorithm.