<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-04-17T22:38:34Z</responseDate><request verb="GetRecord" identifier="oai:www.recercat.cat:2117/427791" metadataPrefix="oai_dc">https://recercat.cat/oai/request</request><GetRecord><record><header><identifier>oai:recercat.cat:2117/427791</identifier><datestamp>2026-02-07T09:47:28Z</datestamp><setSpec>com_2072_1033</setSpec><setSpec>col_2072_452950</setSpec></header><metadata><oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
   <dc:title>RIS phase optimization for near-field 5G positioning: ML-enhanced CRLB minimization</dc:title>
   <dc:creator>Macías López, Carla</dc:creator>
   <dc:creator>Saumell i Portillo, Arnau</dc:creator>
   <dc:creator>Nájar Martón, Montserrat</dc:creator>
   <dc:creator>Closas Gómez, Pau</dc:creator>
   <dc:contributor>Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions</dc:contributor>
   <dc:contributor>Universitat Politècnica de Catalunya. SPCOM - Processament del Senyal i Comunicacions</dc:contributor>
   <dc:subject>Training</dc:subject>
   <dc:subject>Location awareness</dc:subject>
   <dc:subject>Accuracy</dc:subject>
   <dc:subject>5G mobile communication</dc:subject>
   <dc:subject>Optimization methods</dc:subject>
   <dc:subject>Line-of-sight propagation</dc:subject>
   <dc:subject>Machine learning</dc:subject>
   <dc:subject>Reconfigurable intelligent surfaces</dc:subject>
   <dc:subject>Signal processing</dc:subject>
   <dc:subject>Minimization</dc:subject>
   <dc:description>This article addresses near-field localization using Reconfigurable Intelligent Surfaces (RIS) in 5G systems, where Line-of-Sight (LOS) between the base station and the user is obstructed. We propose a RIS phase optimization method based on the minimization of the Cramér-Rao Lower Bound (CRLB). This minimization itself is computationally costly, for which a data-driven method is employed with remarkable computational savings and positioning performance. The main contributions of this work are: (1) the application of machine learning (ML) to enhance CRLB minimization for RIS phase optimization; (2) an overview on RIS phases preprocessing methods to enhance deep neural networks training for the task; and (3) an end-to-end simulation of the positioning task with the presented method, showing a computational improvement without compromising positioning accuracy.</dc:description>
   <dc:description>The UPC authors are within the Signal Processing and Communications Group at UPC recognized as a consolidated research group by the Generalitat de Catalunya through 2021 SGR 01033. This publication is part of the project ROUTE56 with grant PID2019-104945GB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and the project 6-SENSES with grant PID2022-138648OB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and by ERDF A way of making Europe. This work has been partially supported by the National Science Foundation under Awards ECCS-1845833 and CCF-2326559.</dc:description>
   <dc:description>Peer Reviewed</dc:description>
   <dc:description>Postprint (author's final draft)</dc:description>
   <dc:date>2024</dc:date>
   <dc:type>Conference report</dc:type>
   <dc:identifier>Macias, C. [et al.]. RIS phase optimization for near-field 5G positioning: ML-enhanced CRLB minimization. A: European Signal Processing Conference. "32nd European Signal Processing Conference (EUSIPCO 2024): proceedings: 26-30 August 2024, Lyon, France". Institute of Electrical and Electronics Engineers (IEEE), p. 1232-1236. ISBN 978-94-645936-1-7. DOI 10.23919/EUSIPCO63174.2024.10715164 .</dc:identifier>
   <dc:identifier>978-94-645936-1-7</dc:identifier>
   <dc:identifier>https://hdl.handle.net/2117/427791</dc:identifier>
   <dc:identifier>10.23919/EUSIPCO63174.2024.10715164</dc:identifier>
   <dc:language>eng</dc:language>
   <dc:relation>https://ieeexplore.ieee.org/document/10715164</dc:relation>
   <dc:relation>info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-104945GB-I00/ES/TECNOLOGIAS RADIO PARA COMUNICACIONES UBICUAS EN LA EVOLUCION DE 5G A 6G/</dc:relation>
   <dc:relation>info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2021-2023/PID2022-138648OB-I00/ES/COMUNICACIONES 6G Y SENSADO PARA REDES INALAMBRICAS DETERMINISTAS/</dc:relation>
   <dc:rights>Open Access</dc:rights>
   <dc:format>5 p.</dc:format>
   <dc:format>application/pdf</dc:format>
   <dc:publisher>Institute of Electrical and Electronics Engineers (IEEE)</dc:publisher>
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