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Sociedade Brasileira de Telecomunicações


A Comparative Analysis of Vocoders for Communications in Portuguese

This paper analyzes the performance of voice encoders used for digital communications, especially in VoIP calls, for Brazilian Portuguese phonemes. The foc...

SBrT 2010


Performance Analysis of HARQ in WiMAX Networks Considering Imperfect Channel Estimation

Hybrid Automatic Repeat Query (HARQ) is an error correction technique that has become an integral part of most current broadband wireless standards such a...

SBrT 2010


Control in Trellis Codes produced by Finite State Machines with Information Group Zp

A trellis code is the image of a signal mapper from a time invariant group code produced by a Finite State Machine, FSM. Group codes can be described as dy...

SBrT 2010


Electromagnetic Interference Simulation of a Cell Phone in an Aircraft System Using Domain Decomposition Method

Laboratorial experiments to investigate the behavior of numerous embedded avionics installations to onboard electromagnetic interference (EMI) are extremel...

SBrT 2010


An Application Server Approach for Number Portability in IMS networks

Number portability (NP) is an important requirement present in most telephony networks. Typically, NP is regulated by local legislation and is inherently a...

SBrT 2010