Saved in:
Bibliographic Details
Main Authors: Liu, Jinyuan, Guan, Yong Liang, Wu, Tuo, Wong, Kai-Kit, Clerckx, Bruno
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2512.00302
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917405513482240
author Liu, Jinyuan
Guan, Yong Liang
Wu, Tuo
Wong, Kai-Kit
Clerckx, Bruno
author_facet Liu, Jinyuan
Guan, Yong Liang
Wu, Tuo
Wong, Kai-Kit
Clerckx, Bruno
contents As 6G networks demand massive connectivity and stronger interference control, rate-splitting multiple access (RSMA) is attractive because it superposes a common stream and user-private streams and remains effective under imperfect CSIT and heterogeneous traffic. In practical multiuser deployments, two considerations arise: the common stream decoding constraint imposed by the weakest user, and residual inter-user interference can remain non-negligible, particularly in single-input single-output (SISO) broadcast settings and under an imperfect CSIT scenario. Motivated by prior advances of RSMA research, we investigate a complementary mechanism-fluid antenna systems (FAS), with dynamic port reconfiguration supplies adaptive spatial selectivity without altering the RSMA signaling structure. Can FAS help alleviate these considerations and enhance RSMA performance? We develop a tractable correlation-aware analytical framework based on block-correlation models, including constant block correlation (CBC) and variable block correlation (VBC), to capture realistic spatial dependence among ports. Closed-form expressions are derived for outage probability (OP) and average capacity (AC), revealing how port reconfiguration strengthens the weakest effective channel and improves SINR through higher channel gains and lower relative noise impact. Monte Carlo simulations verify the analysis and show that VBC matches simulations more tightly than CBC across all port configurations. Finally, FAS-RSMA provides clear gains over conventional antenna systems and NOMA, achieving lower OP and higher AC by combining RSMA interference management with FAS spatial diversity.
format Preprint
id arxiv_https___arxiv_org_abs_2512_00302
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle FAS-RSMA: Can Fluid Antennas Elevate RSMA Performance?
Liu, Jinyuan
Guan, Yong Liang
Wu, Tuo
Wong, Kai-Kit
Clerckx, Bruno
Signal Processing
As 6G networks demand massive connectivity and stronger interference control, rate-splitting multiple access (RSMA) is attractive because it superposes a common stream and user-private streams and remains effective under imperfect CSIT and heterogeneous traffic. In practical multiuser deployments, two considerations arise: the common stream decoding constraint imposed by the weakest user, and residual inter-user interference can remain non-negligible, particularly in single-input single-output (SISO) broadcast settings and under an imperfect CSIT scenario. Motivated by prior advances of RSMA research, we investigate a complementary mechanism-fluid antenna systems (FAS), with dynamic port reconfiguration supplies adaptive spatial selectivity without altering the RSMA signaling structure. Can FAS help alleviate these considerations and enhance RSMA performance? We develop a tractable correlation-aware analytical framework based on block-correlation models, including constant block correlation (CBC) and variable block correlation (VBC), to capture realistic spatial dependence among ports. Closed-form expressions are derived for outage probability (OP) and average capacity (AC), revealing how port reconfiguration strengthens the weakest effective channel and improves SINR through higher channel gains and lower relative noise impact. Monte Carlo simulations verify the analysis and show that VBC matches simulations more tightly than CBC across all port configurations. Finally, FAS-RSMA provides clear gains over conventional antenna systems and NOMA, achieving lower OP and higher AC by combining RSMA interference management with FAS spatial diversity.
title FAS-RSMA: Can Fluid Antennas Elevate RSMA Performance?
topic Signal Processing
url https://arxiv.org/abs/2512.00302