Ergodic capacity-based energy optimization algorithm in massive MIMO systems

Abstract

Antenna selection and power optimization are low-cost low-complexity alternative methods to capture many of the advantages of massive MIMO systems. However, the computation complexity of antenna selection and power optimization grows rapidly with the number of antennas. Aiming at this problem, we derive an ergodic expression of energy efficiency for massive MIMO systems. And on the basis of it, we present a joint antenna selection and power optimization algorithm. To solve the joint optimization algorithm, the fractional programming is introduced to accelerate the convergence speed. Moreover, the user selection is considered to get the maximum ergodic energy efficiency. The simulation results show that the proposed algorithm can achieve nearly optimal energy efficiency with low computation complexity and fast convergence speed.