Joint Localization and Information Transfer for Reconfigurable Intelligent Surface Aided Full-Duplex Systems

TL;DR

This paper presents a novel joint localization and information transfer scheme in RIS-assisted full-duplex systems, utilizing a compressive sensing approach and a message-passing algorithm with EM tuning, demonstrating improved accuracy and efficiency.

Contribution

It introduces a new joint localization and communication method using RIS, with a novel message-passing algorithm and EM-based grid tuning for enhanced performance.

Findings

The proposed algorithm outperforms existing methods in localization accuracy.

The EM-based tuning reduces model mismatch effects.

Numerical results validate the scheme's feasibility and effectiveness.

Abstract

In this work, we investigate a reconfigurable intelligent surface (RIS) aided integrated sensing and communication scenario, where a base station (BS) communicates with multiple devices in a full-duplex mode, and senses the positions of these devices simultaneously. An RIS is assumed to be mounted on each device to enhance the reflected echoes. Meanwhile, the information of each device is passively transferred to the BS via reflection modulation. We aim to tackle the problem of joint localization and information retrieval at the BS. A grid based parametric model is constructed and the joint estimation problem is formulated as a compressive sensing problem. We propose a novel message-passing algorithm to solve the considered problem, and a progressive approximation method to reduce the computational complexity involved in the message passing. Moreover, an expectation-maximization (EM) algorithm is applied for tuning the grid parameters to mitigate the model mismatch problem. Finally, we analyze the efficacy of the proposed algorithm through the Bayesian Cram\'er-Rao bound. Numerical results demonstrate the feasibility of the proposed scheme and the superior performance of the proposed EM-based message-passing algorithm.