XXX Simpósio Brasileiro de Telecomunicações

Block transmission system, allows transmissions of N symbols simultaneously, with single carrier or multi-carrier modulation. Maximum likelihood optimal reception in multipath channels have a high computational cost of AN, where A is the constellation order (A = 2 for BPSK). To avoid this cost is usual to make symbol by symbol detection after...

O presente trabalho de inicação científica apresenta uma proposta de sistema em tempo real para detecção e a estimação da diração de chegada de sinais de áudio impulsivos. Utiliza-se um hardware específico para processamento em tempo real e um arranjo espacial de 7 microfones. Após detectado, o sinal é processado por um algortmo de estimação de direção...

A televisão transmitida através do protocolo IP(IPTV) está entre as mais promissoras tecnologias para entrega multimídia, permitindo um alto nível de interatividade com o usuario e integração com a internet. A transmissão de fluxos multimídia em tempo real requer garantia de recursos, como limitada perda de pacotes, largura de banda e baixo atraso e...

Cognitive Radio is an innovative technology that allows unlicensed (secondary users) users to opportunistically access channels licensed to other users (primary users). A key procedure in the context of opportunistic access is the spectrum sensing, performed by secondary user to determine whether the channel is idle or busy. However, decisions...

In this paper we propose a solution of hardware and software for a VoIP phone. The processor ADSP-BF518 makes up the core hardware. All software developed and used is free.

In this paper, the authors present a protocol inspired by the natural behaviour of desert ants, to allocate resources in accordance with the emergency degree of patients, in healthcare networks. Simulation results show the decrease of the average delay as the probability of opportunistic access increases, which privileges the emergency reporting of...

This paper presents a discussion on radio over fiber systems (RoF). Some applications and architectures and numerical results for the physical layer performance of a 8- channel OFDM over fiber system are included

Source Separation, Nonlinear Mixtures, Iterative Methods for Equation Solving, Recurrent Networks

An Application Layer - Forward Error Correction (AL-FEC) scheme for mobile reception for the Brazilian Digital Television System (SBTVD) is proposed. The mobile reception in the SBTVD is not as effective due to the Doppler effect that occurs when the user is moving. In order not to modify standards already established, it is proposed to implement an...

Cooperative communications have emerged as a promising solution for wireless networks. In particular, currently there is a growing interest in amplify-and-forward (AF) cooperative systems with relay selection. On the other hand, orthogonal frequency division multiplexing (OFDM) has shown to be a key technology for future wireless communication...