@article{721078e2ef3e48828c027cc17747b327,
title = "Hybrid Centralized-Distributed Precoding in Fronthaul-Constrained CF-mMIMO Systems",
abstract = "We investigate a fronthaul-limited cell-free massive multiple-input multiple-output (CF-mMIMO) system and propose a hybrid centralized-distributed precoding strategy that dynamically adapts to varying fronthaul and spectral efficiency (SE) requirements. The proposed approach divides users into two groups: one served by centralized precoding and the other by distributed precoding. We formulate a novel optimization problem for user grouping and power control aimed at maximizing the sum SE, subject to fronthaul and per-access point (AP) power constraints. To tackle the problem, we transform it into a tractable form and propose efficient solution algorithms. Numerical results confirm the hybrid scheme{\textquoteright}s versatility and superior performance, consistently outperforming fully centralized and distributed approaches across diverse system configurations.",
keywords = "Precoding, Vectors, Optimization, Channel estimation, Spectral efficiency, Resource management, Interference, Downlink, Training, Symbols, fronthaul constraint, spectral efficiency (SE), Cell-free massive multiple-input multiple-output (CF-mMIMO)",
author = "Zahra Mobini and Ngo, \{Hien Quoc\} and Ardavan Rahimian and Anvar Tukmanov and David Townend and Michalis Matthaiou and Cotton, \{Simon L.\}",
year = "2025",
month = oct,
day = "15",
doi = "10.1109/LWC.2025.3622472",
language = "English",
volume = "15",
pages = "295--299",
journal = "IEEE Wireless Communications Letters",
issn = "2162-2337",
publisher = "IEEE Communications Society",
}