XXXI Simpósio Brasileiro de Telecomunicações

Silver code was originally discovered in [1-4] for 2×2 multiple-input multiple-output (MIMO) channels. This code can be constructed algebraically from a particular cyclic division algebra, Silver algebra. Space-Time Block Codes (STBC) based on an order of a cyclic division algebra of index 2 such that the volume of the Dirichlet’s polyhedron of the group...

In this paper, we analyze the impact of single frequency networks on the design of an ISDB-T receiver. We focus on challenges faced during the phases of symbol timing synchronization and equalization. Results in literature show that the challenges stem from the length of the channel impulse response and that opportunities to improve performance...

This paper discusses the dimensioning strategies and the action of regulatory agents in a market that consists of operators has the intention to provide channels for users in the same business environment. It is assumed that users compete for the best service, requests met with lower blocking probability, while operators want to maximize their profits....

Neste trabalho é apresentado o desenvolvimento de antenas com bom desempenho em relação à perda de retorno e ganho na faixa de frequência da TV Digital, que vai de 470 MHz a 806 MHz. É discutido o projeto de uma antena log-periódica de Koch fractal, com dipolos que apresentam três iterações de Koch, e os resultados são comparados com aqueles de uma...

This paper presents the Diga-Energia, a platform of services provided by electric companies for their end-users. The Diga-Energia makes use of Smart Grid technology and the Ginga, a middleware developed for the Brazilian Digital TV. The paper also describes the Smart-Quadro, a prototype that enables sector management through eletrical circuits in...

This paper shown a analysis of concentration of aqueous substances through of variation of eletric permissivity. In order to investigate this variation of relative permittivity of a medium, we used a pair of microstrip antenna positioned at a distance of 120 mm and a spectrum analyzer. The first substance analysed was Vinegar (Acetic acid -...

Este artigo trata da discriminação entre vozes saudáveis e vozes afetadas por patologias na laringe a partir da análise de quantificação de recorrência e redes neurais Multilayer Perceptron (MLP). São empregadas quinze caracterı́sticas obtidas dos gráficos de recorrência. As patologias ları́ngeas consideradas são: paralisia, edema e nódulos nas...

Passive optical networks are becoming more popular as wideband access networks tecnologies. Due to their importance, such networks demands continue supervision scheme. Different techniques could be employed for Optical Network Supervision, among them those using reflectometry have highlighted, because they offer low cost when compared with other...

Este artigo apresenta o uso da álgebra dos Quatérnios, com suas vantagens computacionais em função da redução da quantidade de operações algébricas envolvendo produtos reais usuais indo de encontro com o modelo matricial. Nós propomos um novo esquema de modulação, denominado QuatMod, em sistemas de comunicação digital com uma nova formulação...

This paper presents a new strategy for implementing artificial band width extension (ABWE) systems of speech signals applied to telephony over packet networks. In the open literature, several approaches are presented for theses systems, however, there is still no procedure that can satisfactorily represent speech segments with concentrated energy at...