Achieving Beamfocusing via Two Separated Uniform Linear Arrays

TL;DR

This paper explores how two separated uniform linear arrays can be used for near-field beamforming in 6G networks, enabling multiplexing gains with fewer antennas by analyzing beamwidth and beamdepth.

Contribution

It introduces a novel MLA-based approach for near-field beamforming, providing analytical expressions and demonstrating antenna reduction without performance loss.

Findings

Approximately 36% of antennas can be removed while maintaining beamfocusing.

Near-field effects enable multiplexing of multiple users at different distances.

Analytical expressions for beamwidth and beamdepth are derived.

Abstract

This paper investigates coordinated beamforming using a modular linear array (MLA), composed of a pair of physically separated uniform linear arrays (ULAs), treated as sub-arrays. We focus on how such setups can give rise to near-field effects in 6G networks without requiring many antennas. Unlike conventional far-field beamforming, near-field beamforming enables simultaneous data service to multiple users at different distances in the same angular direction, offering significant multiplexing gains. We present a detailed analysis, including analytical expressions of the beamwidth and beamdepth for the MLA. Our findings reveal that using the MLA approach, we can remove approximately 36% of the antennas in the ULA while achieving the same level of beamfocusing.