XIX Simpósio Brasileiro de Telecomunicações

"We present an analytical method for evaluating the performance of a communication system that employs a convolutional code, a block interleaving with finite interleaving depth, a binary channel that exhibits statistical dependence in the occurrence of errors, and a decoder that implements the Viterbi algorithm with Hamming metric. The main idea is to...

"Performance bounds for convolutional codes over memoryless channels are commonly measured using the distance weight enumerator T(x,y), also referred to as the generating series or the transfer function, of the code. In particular, bounds to the bit error probability are computed using the first few terms of the series expansion of {dT(x,y)/dy}_{x=1}. In...

"Este artigo propõe, através de uma busca computacional sistemática, novos códigos espácio-temporais que transmitem múltiplos sı́mbolos por antena em cada transição de estados. Neste caso, o espalhamento da redundância de codificação não limita-se apenas às transmissões paralelas por múltiplas antenas, mas também ao longo das transmissões seriais em cada...

"Results that can be considerate as classicals from self-similar model paradigm are showed in this work. All measurements and results presented here were based on data traffic traces gathered in our network gateway using a simple yet reliable and efficient method. Several statistical methods, to infer an unbiased and well defined Hurst parameter, are...

"This article presents a purpose of QoS for IP networks. It shows how Internet Service Providers can guaranty QoS, according with the type of flow being controlled. We have described how a high speed network would be implemented without a significant change in the actual internet architecture. Finally, we discussed the internet need to have to provide...

"The following discussion provides some background on why wavelength division multiplexing (WDM) is an important innovation in optical networks and what benefits it can provide. We begin with a high-level view of the segments of the network and forces that are driving the revolution in fiber optical networks. We then examine the differences between...

"comportamento de sólitons em sistemas de transmissão de longa distância. Um dos principais fatores limitantes do desempenho destes sistemas é o ruído de emissão espontânea amplificada – ASE, introduzido pelos amplificadores presentes na transmissão. Os efeitos do ruído ASE e sua interação com os sólitons são analisados graficamente em curvas de 2 e 3D."

"For the microstrip patch resonator, as a planar antenna of a microstrip, a set of equations that represents the electromagnetic fields in the x and z direction as function of the electric field in the y direction are obtained applying the transverse transmission line method. This method is very suitable at microwave and antenna applications, and gives...

"The direct and efficient Transverse Transmission Line (TTL) method is used to analyze the unilateral fin-line resonator. In this method the Maxwell's equations in Fourier transformed domain, are firstly used to obtain the electromagnetic fields in terms of the transversal electromagnetic fields. An inhomogeneous equation system is obtained, in which the...

"The triangular microstrip resonator with steps in the width is a way to simulate the triangular form by the triangular discrete, its analyze is made using the full wave and concise Transverse Transmission Line (TTL) method in the Fourier Transformed Domain (FTD), in conjunction with the Moment Method. Numerical results of the resonance frequency are...