XXXI Simpósio Brasileiro de Telecomunicações

This paper presents a maximum likelihood detector to distributed targets in radars with circular geometry denominated ArcSar. This detector presents the lowest estimation error among all the methods known in the literature. Its efficiency was proven by means of simulation.

This paper compares two speech recognition systems that can be used to develop applications for Android: Julius on server mode and Google. Part of the support to Brazilian Portuguese for Julius was developed by the authors in the context of the FalaBrasil project. Julius also used the FalaBrasil server to provide distributed recognition via Internet,...

This article describes a system for blind sound source localization, which uses two pairs of omnidirectional microphones. The localization method is based on algorithms developed for blind source separation and estimation of the angle of arrival. The inaccuracy in the source localization is analyzed in terms of the distance between the microphones...

Currently, the MPEG-2 Transport Stream (TS) is widely used in many transmission systems, like digital terrestrial television and internet protocol television networks. It is capable of carrying interleaved audio, video, system information, timing and generic data, in an unified transport framework. Regarding receiver synchronization, it employs the...

Este trabalho investiga o desempenho de uma rede de rádios cognitivos (rede secundária) que acessa de forma oportunista o canal licenciado aos usuários de uma rede primária. Emprega-se na análise a métrica power, definida como a razão entre a vazão de um enlace e o atraso observado pelos pacotes transmitidos nesse enlace. Os usuários das redes primária e...

This paper presents the results and analysis of semiconductor optical amplifiers (SOA) as applied in optical nodes for Photonic switching in OPS/OBS future networks. By the same token detailed characterization is provided to investigate physical constraints of optical power, gain and noise figure of SOAs. By using external cavity tunable laser and DFB...

Video Quality Assessment (VQA) is an important factor to establish the quality of video communication and processing systems, such as broadcasting and mobile television. Video quality measurements affect directly video on demand and video services providers, since they need to monitor the broadcasting quality to compute optimal parameters that ensure a...

In the digital signal processing area, one of the most important tasks is the digital filter design. Currently, this procedure is performed with the aid of computational tools, which generally assume filter coefficients represented with floating-point arithmetic. However, during the implementation phase, which is often done in digital signal processors...

O presente trabalho introduz uma nova aproxi- mação ortogonal para a transformada discreta do cosseno de comprimento 8 baseada no trabalho de Brahimi-Bouguezel. O algoritmo rápido para a matriz de transformação proposta re- quer apenas 16 adições. No contexto de compressão de imagens, a transformação proposta supera várias aproximações...

Several traditional models exist to describe the multipath phenomenon in wireless communications, such as Rice, Nakagami-m, Hoyt, and Rayleigh. There are other new ones that propose a generalization in order to better fit fading environments, such as α-µ, κ-µ and η-µ. In this work, the κ-µ extreme distribution, a special case of the κ-µ fading channel,...