Specific Absorption Rate-Aware Multiuser MIMO Assisted by Fluid Antenna System

TL;DR

This paper introduces a SAR-aware multiuser MIMO system assisted by fluid antenna systems, optimizing antenna positions to reduce electromagnetic exposure while maintaining high data rates in 6G networks.

Contribution

It proposes a novel two-layer iterative algorithm for minimizing SAR in FAS-assisted MIMO systems, addressing safety concerns alongside performance optimization.

Findings

Proposed algorithm effectively reduces SAR levels.

FAS-based design outperforms fixed-position antenna systems.

Enhanced data rates with SAR compliance in 6G scenarios.

Abstract

With the development of the upcoming sixth-generation (6G) wireless networks, there is a pressing need for innovative technologies capable of satisfying heightened performance indicators. Fluid antenna system (FAS) is proposed recently as a promising technique to achieve higher data rates and more diversity gains by dynamically changing the positions of the antennas to form a more desirable channel. However, worries regarding the possibly harmful effects of electromagnetic (EM) radiation emitted by devices have arisen as a result of the rapid evolution of advanced techniques in wireless communication systems. Specific absorption rate (SAR) is a widely adopted metric to quantify EM radiation worldwide. In this paper, we investigate the SAR-aware multiuser multiple-input multiple-output (MIMO) communications assisted by FAS. In particular, a two-layer iterative algorithm is proposed to minimize the SAR value under signal-to-interference-plus-noise ratio (SINR) and FAS constraints. Moreover, the minimum weighted SINR maximization problem under SAR and FAS constraints is studied by finding its relationship with the SAR minimization problem. Simulation results verify that the proposed SAR-aware FAS design outperforms the adaptive backoff and fixed-position antenna designs.