XXXI Simpósio Brasileiro de Telecomunicações

Nesse artigo é apresentada uma análise do algoritmo LMS por difusão no contexto especı́fico em que cada nó na rede possui uma SNR diferente. Através de uma análise de autovalores, é mostrada qual condição os passos de adaptação de cada nó da rede deve obedecer, a fim de garantir que o algoritmo apresente uma taxa de convergência fixada. Sob essa...

Neste artigo apresenta-se uma representação para wavelets usando sinais em banda básica, explorando resultados de Kotel’nikov. Detalhes de como obter os processos de envoltória e de fase em baixa frequência são apresentados. A interpretação clássica de wavelets como uma análise com banco de filtros de fator de qualidade constante é revisitada nestas...

Currently, there is a growing interest from the scientific and/or industrial community in respect to methods that offer solutions to the problem of fiducial points detection of human faces. Some methods use the SVM for classification, but we observed that some formulations of optimization problems were not discussed. In this article, we propose to...

A crucial performance measure in the context of the problem of deconvolution is the level of residual intersymbol interference (ISI), a metric that is classically understood and formulated in terms of an L 2 -norm perspective. In order to enhance the scope of ISI quantification, we propose a novel entropy-based performance measure, which is called...

Discriminative filtering is a pattern recognition technique which aim maximize the energy of output signal when a pattern is found. Looking improve the perfomance of filter response, was incorporated the principal component analysis in discriminative filters project. In this work we looking investigate the influence of the amount of principal components in...

Inthispaper,westudyandanalysetheperformance oftheIterativeCorrectionHardDetectiontechniqueforcancellation of nonlinear distortions in OFDMA communication systems. This technique was developed and widely tested for OFDM systems.However,tothebestofourknowledge,theapplicationof this technique in OFDMA systems is unexplored in the literature. The application...

Este artigo apresenta o estudo e projeto de antenas de microfita com geometria em fenda anelar para aplicações em sistemas de navegação via satélite. Duas estruturas são propostas contendo uma fenda anelar construída sobre um laminado de micro-ondas e alimentação em série ou através de um acoplador híbrido de 90° na parte inferior. Através dos...

In this work, we propose a facial recognition system that exploits the multilinear nature of images. The feature extraction occurs in two stages. First, Gabor wavelets are used for feature selection. Then, the higher order singular value decomposition (HOSVD) is applied to separate the multimodal factors of the images. Two approaches based on Euclidean...

In this paper, we analyze the impedance matching characteristic of an optical nanocircuit fed by Gaussian beam. The circuit is composed by a receiving and an emitting dipole connected by a two-wire optical transmission line. The receiving dipole is illuminated by a focused Gaussian beam with λ =830nm and beam waist of 340nm. The numerical analysis of...

This paper presents new results on the objective evaluation of stereoscopic video quality. A balance between the scores provided by classical objective algorithms and the disparity information of the reference video is presented, along with a comparison between the approximations used to compute the local spatial information. The performance of the...