XXXIII Simpósio Brasileiro de Telecomunicações

We propose a relay selection scheme based on fuzzy logic for a cognitive cooperative network. Our goal is to maximize the throughput of the secondary network while minimizing the interference of the selected relay on the primary network. The instantaneous channel state information (CSI) between the relays and the primary destination, and between the...

This article describes the development of a wireless charging system using the inductive resonant coupling technique. The main aim of this system is the creation of a smart wireless power transmitter that could be inserted into various kinds of surfaces as to enable them to transmit energy wirelessly. Complementarily, the idealized system...

This work aims to investigate the suitability of finite impulse response and infinite impulse response digital filters for separating the clusters in a clustered Orthogonal Frequency Division Multiplexing schemes for power line communication systems. In this regards, we formulate the mathematical problem associated with issue. In the following, we...

The fractional Fourier transform over finite fields (GFrFT) based on the matrix function approach is used to design an image encryption scheme. The approach is simpler than the approach based on the construction of an eigenvector set, therefore allowing lower-cost computation systems. The scheme is a secret-key block cipher, that uses a...

Sampling Clock Offset (SCO) estimation is an important issue in Orthogonal Frequency-Division Multiplexing (OFDM) systems because sampling frequency mismatch between the transmitter and the receiver may severely degrade the system performance due to the loss of orthogonality between the subcarriers. SCO estimation in mobile environment is...

Today, the coexistence of Long Term Evolution (LTE) systems operating in adjacent channel with Digital Television (DTV) in the 700 MHz band is under investigation. Many countries are using both technologies to provide respectively high capacity broadband connection and terrestrial television broadcasting. However, the interference between the...

This paper deals with the narrowband and wideband characterization of the urban channel in the 2.48 GHz band starting from signal measurements carried in Rio de Janeiro. Fading statistics, coverage and adjusted prediction models are determined and temporal dispersion is studied through the delay spread and coherence band calculated from the power...

Neste trabalho é realizado um estudo de antenas ressoadoras dielétricas (DRA) da matriz cerâmica FeNbTiO6 (FNTO). Para tal, as amostras são adicionadas com ZnO nas seguintes proporções 0%, 8%, 16% e 25%. As propriedades dielétricas de micro-ondas apresentaram permissividade entre 47,23 e 63,77, além de um aumento das perdas dielétricas. Observou-se...

Neste artigo, introduz-se um método para reconhecimento automático de regiões de interesse em imagens radiográficas de cães. O objetivo é estimar o ângulo de Norberg, parâmetro que apoia o diagnóstico de uma anomalia denominada displasia coxofemoral. A técnica é baseada no pré-processamento da imagem sob análise, no uso da transformada de Hough para...

This contribution aims to improve the data transmission performance of a power line communication (PLC) scheme with quantized feedback channel. It is considered a 2 × 2 PLC time-varying channel. A quantized channel state information is fed back to update the transmitter aiming at maximizing the instantaneous signal-to-noise ratio. In order...