RIS-Assisted Cell-Free Massive MIMO: RIS-MS Selection in FR1 and FR3

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: de la Fuente, Alejandro, Galindo, Fernando, García-Bárbulo, Uriel, Arana-Alegre, Sandra-Noemy, García-Morales, Jan
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866911605852209152
author de la Fuente, Alejandro
Galindo, Fernando
García-Bárbulo, Uriel
Arana-Alegre, Sandra-Noemy
García-Morales, Jan
author_facet de la Fuente, Alejandro
Galindo, Fernando
García-Bárbulo, Uriel
Arana-Alegre, Sandra-Noemy
García-Morales, Jan
contents This paper explores the integration of reconfigurable intelligent surfaces (RISs) into cell-free massive multiple-input-multiple-output (CF-mMIMO) networks operating in FR1 and FR3 frequency bands. We present a comprehensive framework for analyzing RIS-assisted CF-mMIMO systems under realistic propagation conditions, accounting for frequency-dependent characteristics and RIS configurations. A novel RIS-user association algorithm is proposed to optimize phase-shift settings by assigning each RIS to a single user based on line of sight (LoS) connectivity. The system model incorporates spatially correlated Ricean fading channels and employs scalable partial-minimum mean square error (P-MMSE) combining. The numerical results demonstrate that the proposed RIS-user selection strategy significantly improves the spectral efficiency compared to random or exhaustive RIS configurations, particularly when the number of RISs is moderate. We also analyze the trade-off between training overhead and performance gains, showing that excessive pilot requirements can offset benefits when RIS density or element count increases. The results highlight the potential of the FR3 bands for RIS-assisted CF-mMIMO, provided advanced channel estimation techniques are adopted to mitigate overhead. These findings emphasize the importance of intelligent RIS-user pairing and scalable estimation methods for future 6G deployments.
format Preprint
id arxiv_https___arxiv_org_abs_2604_17634
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle RIS-Assisted Cell-Free Massive MIMO: RIS-MS Selection in FR1 and FR3
de la Fuente, Alejandro
Galindo, Fernando
García-Bárbulo, Uriel
Arana-Alegre, Sandra-Noemy
García-Morales, Jan
Signal Processing
This paper explores the integration of reconfigurable intelligent surfaces (RISs) into cell-free massive multiple-input-multiple-output (CF-mMIMO) networks operating in FR1 and FR3 frequency bands. We present a comprehensive framework for analyzing RIS-assisted CF-mMIMO systems under realistic propagation conditions, accounting for frequency-dependent characteristics and RIS configurations. A novel RIS-user association algorithm is proposed to optimize phase-shift settings by assigning each RIS to a single user based on line of sight (LoS) connectivity. The system model incorporates spatially correlated Ricean fading channels and employs scalable partial-minimum mean square error (P-MMSE) combining. The numerical results demonstrate that the proposed RIS-user selection strategy significantly improves the spectral efficiency compared to random or exhaustive RIS configurations, particularly when the number of RISs is moderate. We also analyze the trade-off between training overhead and performance gains, showing that excessive pilot requirements can offset benefits when RIS density or element count increases. The results highlight the potential of the FR3 bands for RIS-assisted CF-mMIMO, provided advanced channel estimation techniques are adopted to mitigate overhead. These findings emphasize the importance of intelligent RIS-user pairing and scalable estimation methods for future 6G deployments.
title RIS-Assisted Cell-Free Massive MIMO: RIS-MS Selection in FR1 and FR3
topic Signal Processing
url https://arxiv.org/abs/2604.17634