XXXIII Simpósio Brasileiro de Telecomunicações

The l0-LMS is an adaptive algorithms recently proposed for the identification of sparse systems. Its strategy consists in modifying the cost function of the standard LMS algorithm by adding a term that penalizes non-sparse solutions. Compared to its precursors, this algorithm has proven very competitive. However, the advantages of the l0-LMS...

This article presents a Quality of Experience (QoE)- aware resource allocation framework aiming at maximizing the minimum Mean Opinion Score (MOS) of the users in a wireless network. The subscribers of a network are divided into service plans, where each one has a satisfaction factor to achieve, i.e., a minimum number of users to satisfy. This is an...

This article presents results of the application of adaptative filters, using algorithms NLMS (Normalized Least Mean Square) and RLS (Recursive Least Square), for the reduc- tion of deviations in weather forecasts. The climatic parameter that me consider is the meridional wind in the region covered by the atmospheric forecast model Eta/CPTEC with...

This paper presents a new beamforming algorithm for mobile communication systems. Such an algorithm is developed by modifying the optimization problem used for developing the adaptive-projection constrained stochastic gradient (AP-CSG) algorithm. This modification consists of replacing an affine constraint by a quadratic one. As a result, the...

Higher-order statistics for the phase process of a general η-µ fading model is obtained. In particular, such statistics is derived for the case in which imbalance of multipath clusters between in-phase and quadrature signals in the η-µ fading model exists. Exact, closed-form expressions for (i) the joint probability density function of the envelope,...

Um modelo de desvanecimento para o sinal Nakagami-m complexo é proposto. Uma expressão exata e fechada para a função densidade de probabilidade conjunta envolvendo duas envoltórias e as duas fases correspondentes é obtida. Consideram-se os sinais com o mesmo fator de desvane- cimento mas com potências arbitrárias. O modelo proposto aqui abre uma...

This paper presents a new algorithm for beamforming in mobile communication systems. This algorithm is based on the linearly-constrained minimum-variance (LCMV) approach and also on a rank-reducing strategy. In contrast to another reduced-rank algorithm from the literature, the proposed one satisfies the unit-gain constraint of the LCMV...

This paper is the result of a study on security and privacy on the Internet. An analysis will be done by addressing the technical aspects of communication in IP networks pointing at which layers of the network is possible to obtain information that compromise user privacy causing failure in network security. Some network security breaches that...

In this article, we apply non-linear modulation techniques to continuous variables quantum key distribution protocols. More specifically, we try to relate the interference of spying the quantum channel to the probability of anomaly defined in non-linear modulation schemes. In this way, the probability of anomaly can be used to quantify the spy’s...

In recent papers, we have proposed and analyzed an innovative low-cost framework for the construction of me- teorological radars, based on two fixed wide-beam antennas. In those papers, it has been found that a very large amount of signal samples would be required to ensure an adequate performance for the proposed radar. On the other hand, it has...