Simultaneous Near-Field THz Communications and Sensing with Full Duplex Metasurface Transceivers

TL;DR

This paper introduces a full duplex XL MIMO system with reconfigurable metasurface antennas for simultaneous near-field THz communications and sensing, optimizing for high data rates and accurate target localization.

Contribution

It presents a novel PEB analysis and an optimization framework for metasurface-based precoding, enabling joint near-field communication and sensing at THz frequencies.

Findings

Validated joint communication and sensing capabilities through simulations

Demonstrated optimization of sum-rate with localization constraints

Showcased the effectiveness of metasurface antennas in near-field THz applications

Abstract

In this paper, a Full Duplex (FD) eXtremely Large (XL) Multiple-Input Multiple-Output (MIMO) node equipped with reconfigurable metasurface antennas at its transmission and reception sides is considered, which is optimized for simultaneous multi-user communications and sensing in the near-field regime at THz frequencies. We first present a novel Position Error Bound (PEB) analysis for the spatial parameters of multiple targets in the vicinity of the FD node, via the received backscattered data signals, and devise an optimization framework for its metasurface-based precoder and combiner. Then, we formulate and solve an optimization problem aiming at the downlink sum-rate maximization, while simultaneously ensuring a minimum PEB requirement for targets' localization. Our simulation results for a sub-THz system setup validate the joint near-field communications and sensing capability of the proposed FD XL MIMO scheme with metasurfaces antennas, showcasing the interplay of its various design parameters.