XLIV Simpósio Brasileiro de Telecomunicações e Processamento de Sinais

Adaptive Networks (ANs) are groups of agents that collaborate to perform data-driven tasks such as optimization and inference. This work evaluates distributed filter estimation for unsupervised equalization over ANs using adaptive signal processing algorithms: the Constant Modulus Algorithm and Single Channel Independent Component Analysis (SCICA)....

Este trabalho investiga a detecção de falhas em rolamentos de um motor elétrico, utilizando modelos de aprendizado de máquina de baixo custo computacional. Expandindo um estudo anterior, são incorporados descritores extraídos da banda completa e de sub-bandas de sinais de aceleração, velocidade e deslocamento, baseados na expertise técnica de analistas...

O uso de múltiplos rádios definidos por software (SDRs - Software Defined Radios) de baixo custo em arranjos de antenas com mais de dois elementos impõe desafios significativos de sincronização entre dispositivos SDRs, essenciais para garantir a coerência de fase. Quando múltiplos dispositivos são operados de forma independente, diferenças de...

Visible light communication (VLC) provides a unified framework for wireless data transmission and illumination, but its practical deployment requires transmission schemes that jointly satisfy communication and lighting constraints. In color-shift keying (CSK) systems, dimming remains a challenging and underexplored problem because the average optical...

This work presents experimental results for a 20.3 km fiber-optic link operating at 3.5 GHz for potential Radio-over-Fiber (RoF) applications. The system employs OFDM together with denoising-assisted channel estimation and digital polynomial linearization based on a Least Squares (LS) training algorithm. To evaluate the minimum input power required to...

This paper presents an IoT smart parking system that, through microcontrollers, orchestrates communication between a management gateway and mobile robots via the CoAP protocol. The architecture implements automatic parking space allocation and proposes a zone-based anti-collision algorithm. The use of the CoAP protocol ensures low latency for real-time...

This work analyzes the secrecy performance of a RIS-assisted wiretap system over κ-μ fading channels, accounting for the statistical behavior of the channel phase. The RIS is configured to provide perfect phase alignment at the legitimate receiver, whereas the eavesdropping link experiences imperfect phase alignment. Closed-form approximate expressions...

We demonstrate a 20 GHz single mode fiber integrated broadband resonant electro-optic frequency comb generated from an acetylene-stabilized continuous-wave laser at 1542.384 nm. The optical spectrum spans the S, C, and L optical communication bands through nonlinear spectral broadening in highly nonlinear fibers. Measurements in the optical and...

Self-supervised speech models such as wav2vec 2.0 produce high-dimensional embeddings that encode multiple aspects of vocal production, although the internal organization of these representations remains difficult to interpret. This work investigates the geometric structure of speaker-level speech embeddings extracted from a fine-tuned wav2vec 2.0 model...

This work analyzes signal propagation in Long Range (LoRa) wireless links for precision agriculture by comparing classical propagation models and models that account for vegetation attenuation against experimental measurements in three scenarios: short grass, maize crop, and palm plantation. Classical models include Log-distance, Close-In (CI), and...