XL-MIMO Energy-Efficient Antenna Selection under Non-Stationary Channels

TL;DR

This paper proposes an antenna selection algorithm for XL-MIMO systems with non-stationary channels, significantly reducing power consumption and computational load while maintaining high spectral efficiency.

Contribution

It introduces a novel antenna selection method tailored for XL-MIMO with non-stationary channels, enhancing energy efficiency without major spectral efficiency loss.

Findings

Energy efficiency increased by selecting fewer antennas

Less than 20% of antennas can be used without major SE loss

Algorithm reduces computational burden and power consumption

Abstract

Massive multiple-input-multiple-output (M-MIMO) is a key technology for 5G networks. Within this research area, new types of deployment are arising, such as the extremely-large regime (XL- MIMO), where the antenna array at the base station (BS) has extreme dimensions. As a consequence, spatial non-stationary properties appear as the users see only a portion of the antenna array, which is called visibility region (VR). In this challenging transmission-reception scenario, an algorithm to select the appropriate antenna-elements for processing the received signal of a given user in the uplink (UL), as well as to transmit the signal of this user during downlink (DL) is proposed. The advantage of not using all the available antenna-elements at the BS is the computational burden and circuit power consumption reduction, improving the energy efficiency (EE) substantially. Numerical results demonstrate that one can increase the EE without compromising considerably the spectral efficiency (SE). Under few active users scenario, the performance of the XL-MIMO system shows that the EE is maximized using less than 20% of the antenna-elements of the array, without compromising the SE severely.