We investigate joint localization and synchronization in the downlink of a distributed multiple-input-multiple-output (D-MIMO) system, aiming to estimate the position and phase offset of a single-antenna user equipment (UE) using downlink transmissions of multiple phase-synchronized, multi-antenna access points (APs). We propose two transmission protocols: sequential (P1) and simultaneous (P2) AP transmissions, together with the ML estimators that either leverage (coherent estimator) or disregard phase information (non-coherent estimator). Simulation results reveal that downlink D-MIMO holds significant potential for high-accuracy localization while showing that P2 provides superior localization performance and reduced transmission latency.
@article{arxiv.2504.10087,
title = {Joint Localization and Synchronization in Downlink Distributed MIMO},
author = {Sauradeep Dey and Musa Furkan Keskin and Dario Tagliaferri and Gonzalo Seco-Granados and Henk Wymeersch},
journal= {arXiv preprint arXiv:2504.10087},
year = {2025}
}