XLI Simpósio Brasileiro de Telecomunicações e Processamento de Sinais

Plane-wave Imaging (PWI) is used in ultrasound to insonify the region of interest to visualize it as an image. In PWI a diversity of angles and a much higher wavefield is used than in the common synthetic aperture approach. For good imaging, many plane wave emissions are required. To reduce the emission time, the concept of simultaneous emission of plane...

O trabalho a seguir foi desenvolvido com o intuito de descrever o desenvolvimento de materiais absorvedores porosos baseados em compósitos magnéticos para a banda de frequências X. A espuma proposta se baseia em um compósito magnético baseado na dispersão de um aditivo magnético em uma matriz dielétrica de borracha de silicone. Foi induzida a inserção de...

This paper analyzes the performance of a cell-averaging constant false alarm rate (CA-CFAR) algorithm designed for K-distributed clutter in High-Frequency Surface Wave Radar applications (HFSWR). Due to complex scattering mechanisms, the clutter returns in the range-Doppler spectrum are highly non-homogeneous. This study compares a closed-form...

Distributed massive multiple-input multiple-output (MIMO) networks, also known as cell-free, are promising solution to increase efficiency in beyond 5G systems. Pilot-based uplink (UL) channel estimation directly influences transmission efficiency, as it is used to mitigate interference and noise from user equipment (UEs). In this context, this work uses...

This article presents an investigation of the effect of applying Penrose symmetry on microstrip antenas, evaluating the influence on the radiation parameters from changes in the dimensional values of this type of structure. This quasi-periodic model will be applied to the antena ground plane for an operating frequency of 2.45GHz. The variation of the...

Neste trabalho, avaliamos experimentalmente uma arquitetura híbrida FiWi (fiber/wireless) que combina fibra óptica, (FSO, free space optical), ondas milimétricas e (VLC, visible light communication) em uma mesma topologia de rede. Para o fronthaul, um enlace de 20 km de fibra óptica seguido por um enlace FSO de 1,5 m foi implementado. Para o acesso, um...

Barkhausen Magnetic Noise analysis has been carried out to monitor constituents harmful to the properties of ferromagnetic materials. Empirical mode decomposition has been applied to decompose complex signals into simpler components. In the present work this is applied to detect the harmful constituent sigma in a stainless steel. Samples both without and...

Cattle theft is a national and growing problem in Brazil. It is known that, during theft, animals move atypically, changing the conditions of propagation in the environment, impacting the amplitude of the radiofrequency signals received at the location. In this paper, we investigate the feasibility of using the observation of radiofrequency signals...

Precision farming has become essential for increasing food production in the previously used cultivation area. Therefore, animal health monitoring and estrus detection are essential to increase dairy farming production. Wireless Sensor Networks play an important role in replacing manual methods impractical for large herds, and they can be used to collect...

Dos 5570 municípios brasileiros, ainda há 1309 municípios sem conexão à Internet por fibra óptica, o que levanta a seguinte questão: qual a melhor forma de investir nessa cobertura para os municípios? Este estudo buscou, através do cálculo da Árvore Geradora Mínima com algoritmos exato e heurístico, trazer alguma luz à questão. Foi realizado o cálculo do...