Employing Antenna Selection to Improve Energy-Efficiency in Massive MIMO Systems

TL;DR

This paper proposes an antenna selection algorithm for massive MIMO systems that improves energy efficiency by choosing antennas based on channel conditions, supported by a tight power consumption approximation and simulation results.

Contribution

It introduces a novel antenna selection method tailored for energy efficiency in massive MIMO, with a mathematical approximation for power consumption and demonstrated performance gains.

Findings

Significant energy efficiency improvements with antenna selection.

A tight power consumption approximation using Wishart theorem.

Simulation confirms the effectiveness of the proposed method.

Abstract

Massive MIMO systems promise high data rates by employing large number of antennas, which also increases the power usage of the system as a consequence. This creates an optimization problem which specifies how many antennas the system should employ in order to operate with maximal energy efficiency. Our main goal is to consider a base station with a fixed number of antennas, such that the system can operate with a smaller subset of antennas according to the number of active user terminals, which may vary over time. Thus, in this paper we propose an antenna selection algorithm which selects the best antennas according to the better channel conditions with respect to the users, aiming at improving the overall energy efficiency. Then, due to the complexity of the mathematical formulation, a tight approximation for the consumed power is presented, using the Wishart theorem, and it is used to find a deterministic formulation for the energy efficiency. Simulation results show that the approximation is quite tight and that there is significant improvement in terms of energy efficiency when antenna selection is employed.