Energy-Efficient Power Control Optimization Algorithm in Massive MIMO Systems

This paper considers a single-cell multi-user uplink massive MIMO system. In order to meet user quality of service requirements and decrease the channel estimation error, an optimal resource allocation algorithm of jointly the number of antennas of base station (BS), the number of pilot sequences, the transmit power and pilot power under maximization energy efficiency is proposed. In this paper, we simplify approximate expression of the lower bound of energy efficiency. Unlike conventional iterative algorithm for solving the optimal number of BS antennas, we derived a closed-form expression to solve the optimal number of BS antennas using Lambert W function. In addition, using fractional programming, according to the block coordinate descent (BCD) and Bisection algorithm, we proposed a nested loop iterative optimization algorithm to jointly optimize the pilot power, transmit power, and number of BS antennas in order to improve the system's energy efficiency. Simulation results show that the energy efficiency our proposed schemes is 7% higher than of other existing algorithm and can improve system performance.