arXiv subjects

Hugerles S. Silva

Publications and source records attributed to Hugerles S. Silva.

11 recordsLinked to original sources

arXiv2026

Receive Diversity for Differential Binary Noise Modulation

Differential binary noise (DBN) modulation encodes information in the polarity transition of a reused noise realization, dispensing channel state information and carrier-phase recovery. This letter proposes single-input multiple-output (SIMO) reception for DBN via post-correlation decision-statistic combining, followed by one zero-threshold decision. The combined statistic is a Hermitian quadratic form in complex Gaussian vectors, yielding an exact conditional bit error probability (BEP) with no Gaussian approximation. Averaging it over $\kappa$-$\mu$ fading and the reused energy gives the exact BEP for arbitrary weights. Because that energy is shared, its deep fades are common to every branch, and the observation length caps the diversity order at $\min(M\mu,N)$. The deflection-optimal weights follow in closed form and interpolate soft combining and power weighting. Measured 65 GHz indoor non-line-of-sight (NLoS) results quantify the trade-off between spatial resources and observation length.

eess.SP↗

arXiv2026

On-Off Digital Noise Modulation with Fluid Antenna Systems over $\kappa$-$\mu$ Fading Channels

This letter proposes the integration of on-off digital noise (OODN) modulation with fluid antenna systems (FASs). A unified analytical framework is developed to evaluate the performance of FAS- assisted OODN receivers over additive white Gaussian noise and generalized \k{appa}-{\mu} fading channels. The analysis incorporates fluid antenna port selection, the number of available ports, and spatial correlation. Analytical expressions for the average bit error probability are derived and the achievable diversity order is characterized. All expressions are validated through Monte Carlo simulations. Results demonstrate that the spatial diversity provided by the FAS significantly enhances the reliability of OODN transmissions while preserving their inherent low-complexity, non-coherent operation without carrier-phase recovery. The proposed framework establishes a new research direction for energy-efficient Internet of Things (IoT) and machine-type communication systems.

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arXiv2026

On--Off Digital Noise Modulation under Multi-User Co-Channel Interference

This letter analyzes the performance of on-off digital noise (OODN) modulation under multi-user scenarios. While prior works have addressed single-link operation, the impact of co-channel interference remains unexplored. We consider $K$ synchronous OODN interferers over AWGN and fading channels and derive a unified analytical framework for the bit error probability (BEP). The optimal likelihood-ratio detection threshold is obtained, along with a closed-form expression for the resulting irreducible error floor, which climbs geometrically with the number of co-channel interferers and yields a simple admission-control rule on network density. The analysis is extended to $\kappa$-$\mu$ fading, covering practical millimeter-wave channels with dominant line-of-sight components. Results, corroborated by Monte Carlo simulation, show that the floor is governed by the on-off interference and the non-coherent detector rather than by the noise waveform.

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arXiv2025

Optimal Bit Detection in Thermal Noise Communication Systems Under Rician Fading

Thermal noise communication (TNC) enables ultra-low-power wireless links for Internet of Things (IoT) devices by modulating the variance of thermal noise, rather than using active carriers. Existing analyses often rely on Gaussian approximations and overlook fading effects, which limits their accuracy. This paper presents an accurate analytical framework for optimal bit detection in TNC systems under Rician fading. Using chi-squared statistics, we derive the optimal maximum-likelihood detection threshold and an expression for the bit error probability (BEP) via Gauss-Laguerre quadrature. The proposed model eliminates approximation errors and accurately characterizes performance for finite sample sizes. Monte Carlo simulations confirm the analytical results and demonstrate significant improvements in BEP compared with suboptimal Gaussian-based detection. Furthermore, the influence of key parameters, sample size, resistance ratio, and Rician K-factor, is quantified. The proposed framework provides a solid foundation for designing energy-efficient TNC receivers in future B5G/6G and large-scale IoT systems.

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arXiv2025

A Survey on Noise-Based Communication

The proliferation of sixth-generation (6G) networks and the massive Internet of Things (IoT) demand wireless communication technologies that are ultra-low-power, secure, and covert. Noise-based communication has emerged as a transformative paradigm that meets these demands by encoding information directly into the statistical properties of noise, rather than using traditional deterministic carriers. This survey provides a comprehensive synthesis of this field, systematically exploring its fundamental principles and key methodologies, including thermal noise modulation (TherMod), noise modulation (NoiseMod) and its variants, and the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange. We address critical practical challenges such as channel estimation and hardware implementation, and highlight emerging applications in simultaneous wireless information and power transfer (SWIPT) and non-orthogonal multiple access (NOMA). Our analysis confirms that noise-based systems offer unparalleled advantages in energy efficiency and covertness, and we conclude by outlining future research directions to realize their potential for enabling the next generation of autonomous and secure wireless networks.

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arXiv2025

Slow, Fast and Opportunistic FAMA: A Spatial Block-Correlation Analysis under Nakagami-m Fading Channels

This paper studies slow, fast and opportunistic fluid antenna multiple access (FAMA) under the effect of Nakagami-m fading channels, considering the new and realistic spatial blockcorrelation model. Expressions for the outage probability (OP), based on the signal-to-interference ratio (SIR), are derived for slow FAMA. Interestingly, we provide mathematical relationships that allow the expressions of fast FAMA to be obtained from slow FAMA. Multiplexing gains for an opportunistic FAMA (OFAMA) network are presented for both slow and fast FAMA scenarios. Our analytical results are validated through Monte Carlo simulations, under various channel and system parameters. All expressions derived in this work are original.

math.ST↗

arXiv2025

On the Performance of THz Wireless Systems over $\alpha$-$\mathcal{F}$ Channels with Beam Misalignment, Mobility and Hardware Impairments

This paper investigates the performance of terahertz (THz) wireless systems over the $\alpha$-$\mathcal{F}$ fading channels with beam misalignment, mobility and hardware impairments. New expressions are derived for the probability density, cumulative distribution, and higher-order moments of the instantaneous signal-to-noise ratio (SNR). Building upon the aforementioned expressions, we extract novel formulas for the outage probability (OP), average symbol error probability, and average channel capacity. Asymptotic expressions are also derived, providing useful insights into system performance in the high-SNR regime. Furthermore, an upper bound on the capacity metric is obtained. Monte Carlo simulation results are presented to validate the developed analytical framework.

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arXiv2025

LNN-powered Fluid Antenna Multiple Access

Fluid antenna systems represent an innovative approach in wireless communication, recently applied in multiple access to optimize the signal-to-interference-plus-noise ratio through port selection. This letter frames the port selection problem as a multi-label classification task for the first time, improving best-port selection with limited port observations. We address this challenge by leveraging liquid neural networks (LNNs) to predict the optimal port under emerging fluid antenna multiple access scenarios alongside a more general $α$-$μ$ fading model. We also apply hyperparameter optimization to refine LNN architectures for different observation scenarios. Our approach yields lower outage probability values than existing methods.

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arXiv2025

Cascaded Multiwire-PLC/Multiple-VLC System: Characterization and Performance

This paper proposes a cascaded multiwire-power line communication (PLC)/multiple-visible light communication (VLC) system. This hybrid architecture offers low installation cost, enhanced performance, practical feasibility, and a wide range of applications. Novel analytical expressions are derived for key statistics and outage probability, bit error probability, and ergodic channel capacity metrics. Furthermore, the analytical results are validated through Monte Carlo simulations, with several performance curves presented under various channel and PLC/VLC system parameters. All expressions derived in this work are original and have not been previously published. Our proposed system proves feasible for smart environments, green communication systems, internet of things networks, industrial environments, and next-generation networks.

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arXiv2025

Physical-Layer Security of Pinching-Antenna Systems

In this paper, we investigate the performance of physical-layer security of a pinching-antenna system on a lossless dielectric waveguide. In particular, the system uses a single pinching-antenna to convey confidential information from a base station to a legitimate destination equipped with a single antenna, while an eavesdropper, also equipped with a single antenna, attempts to decode the transmitted information. As such, the performance of the pinching-antenna system is evaluated in terms of average secrecy capacity, strictly positive secrecy capacity, and secrecy outage probability. To this end, accurate mathematical expressions for the aforementioned performance metrics are provided. To validate the analysis, the analytical results are numerically evaluated and further validated through Monte-Carlo simulations. The results demonstrate that secrecy capacity between the base station and the legitimate destination improves when the height of the pinching-antenna placed closer to the destination. Additionally, the performance can be improved when the eavesdropper's location over a rectangular area increases.

cs.IT↗

arXiv2025

On the Secrecy Performance of $α$-$\mathcal{F}$ Channels with Pointing Errors

This paper investigates the physical layer security (PLS) performance of $α$-$\mathcal{F}$ fading channels with pointing errors under passive and active eavesdropping scenarios. Novel analytical expressions are derived for key PLS metrics, including the probability of strictly positive secrecy capacity, the average secrecy capacity, and the secure outage probability. An asymptotic analysis is also investigated to provide further insights into the system behavior under high signal-to-noise ratio conditions. The analytical results are validated through Monte Carlo simulations, with several performance curves presented for a range of channel and system parameters. All expressions derived in this work are original and have not been previously published.

cs.IT↗