A copula-based attention time-series model reconstructs unobserved port signals in FAMA systems from random partial observations, reaching NMSE of order 10^{-4} when observed ports exceed spatial DoF under rich and finite-scattering channels.
Fluid antenna systems: A geometric approach to error probability and fundamental limits
6 Pith papers cite this work. Polarity classification is still indexing.
6
Pith papers citing it
abstract
The fluid antenna system (FAS) concept is an emerging paradigm that promotes the utilization of the feature of shape and position reconfigurability in antennas to broaden the design of wireless communication systems. This also means that spatial diversity can be exploited in an unconventional way. However, a rigorous framework for error probability analysis of FAS under realistic spatially correlated channels has been lacking. In this paper, we fill this gap by deriving a tight, closed-form asymptotic expression for the symbol error rate (SER) that establishes the fundamental scaling law linking the system's SER to the channel's spatial correlation structure. A key insight of our analysis is that the achievable diversity gain is governed not by the number of antenna ports, but by the channel's effective rank. To find this critical parameter, we propose a novel dual-pronged approach. First of all, we develop a geometry-based algorithm that extracts distinct performance thresholds from the channel's eigenvalue spectrum. Second, we theoretically prove that the effective rank converges to a fundamental limit dictated solely by the antenna's normalized aperture width. We further establish the equivalence between the threshold identified by the geometric algorithm and the derived theoretical limit, providing rigorous validation for the proposed method. Our effective rank model achieves higher accuracy than existing approaches in the literature. Building on this framework, we offer a complete characterization of diversity and coding gains. The analysis leads to a definitive design insight: FAS performance improvements are fundamentally driven by enlarging the antenna's explorable aperture, which increases the effective channel rank, whereas increasing port density within a fixed aperture yields diminishing returns.
years
2026 6representative citing papers
Derives exact closed-form BLER and rate for FAS-enabled HRLLC with switching delay, proves strict unimodality in port dimension for reliability/rate/energy efficiency, and characterizes a switching-delay threshold for gains over fixed-position antennas.
PUMA integrates phased arrays with fluid antennas at UEs for analog-domain interference mitigation and high gain using minimal RF chains, claiming superior data rates over FAMA and CUMA in theoretical analysis and simulations for 6G.
The paper introduces a response-aware codebook selection method for FRIS-assisted index modulation to improve spatial index reliability in 6G wireless communications.
A dimensional scaling law for continuous fluid-antenna high-SNR probability remains accurate for a two-user MMSE setup, and per-user high-SINR probability can exceed the single-user HSP despite interference.
Derives closed-form outage probability for a SIM-assisted FAS model using BDMA and optimizes phase shifts to minimize outage with numerical validation.
citing papers explorer
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Fast Fluid Antenna Multiple Access
A copula-based attention time-series model reconstructs unobserved port signals in FAMA systems from random partial observations, reaching NMSE of order 10^{-4} when observed ports exceed spatial DoF under rich and finite-scattering channels.
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Fluid Antenna Systems Enabling 6G HRLLC With Port Switching Delay
Derives exact closed-form BLER and rate for FAS-enabled HRLLC with switching delay, proves strict unimodality in port dimension for reliability/rate/energy efficiency, and characterizes a switching-delay threshold for gains over fixed-position antennas.
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Phased Ultra Massive Array (PUMA)
PUMA integrates phased arrays with fluid antennas at UEs for analog-domain interference mitigation and high gain using minimal RF chains, claiming superior data rates over FAMA and CUMA in theoretical analysis and simulations for 6G.
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Fluid RIS (FRIS)-Assisted Index Modulation for 6G Wireless Communications
The paper introduces a response-aware codebook selection method for FRIS-assisted index modulation to improve spatial index reliability in 6G wireless communications.
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Spatial Limits of Fluid Antenna Systems
A dimensional scaling law for continuous fluid-antenna high-SNR probability remains accurate for a two-user MMSE setup, and per-user high-SINR probability can exceed the single-user HSP despite interference.
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Stacked Intelligent Metasurface-Assisted Fluid Antenna Systems: Outage Probability
Derives closed-form outage probability for a SIM-assisted FAS model using BDMA and optimizes phase shifts to minimize outage with numerical validation.