Array Size Reduction for High-Rank LOS MIMO ULAs

TL;DR

This paper introduces an extended LOS MIMO channel model with a phase shifting term, enabling reduced antenna array sizes while maintaining high spatial multiplexing capabilities.

Contribution

It proposes a novel channel model incorporating phase shifts and demonstrates how dielectric materials can optimize antenna spacing for high-rank LOS MIMO systems.

Findings

Phase shifting improves channel conditioning.

Optimal antenna spacing can be reduced.

Dielectric materials enable size reduction.

Abstract

In this paper we propose an extended LOS MIMO channel model, which considers an additional phase shifting term in the transmission path, and which provides the potential to improve channel conditioning significantly. We show that this phase shifting can, for example, be achieved by adding a dielectric material between the transmitting and receiving antennas, where the phase shift is dependent on the distance the waves travel in the medium. Using that distance as a design parameter we demonstrate that the optimal spacing between antenna elements of uniform linear arrays, achieving full spatial multiplexing, can be reduced compared with the well-known spacing criterion from previous investigations.