The reflection of an acoustic signal on walls or objects in an enclosed environment is perceived as reverbera- tion. It is present daily in conference room...

• F. de S. Farias
• R. Coelho

• The reflection of an acoustic signal on walls or objects in an enclosed environment is perceived as reverbera- tion. It is present daily in conference rooms
• tunnels and any closed spaces. The presence of reverberation can degrade speech intelligibility and the performance of tasks that depend on it
• such as speech or speaker recognition. Many methods were proposed to attenuate this degradation. A family of such methods acts on clean speech
• applying gains on parts of the signal in order to improve intelligible when reverberated. These methods are called adaptive gain methods. This study aims to evaluate the effect of two adaptive gain methods
• Adaptive Gain Control (AGC) and Steady-State Suppression (SSS)
• in speech intelligibility. The evaluation uses four objective measures: Coherence Signal Intelligibility Index (CSII)
• Short Time Objective Intelligibility (STOI)
• Speech Reverberation to Modulation Ratio (SRMR) and Weighted Short Time Objective Intelligibility (WSTOI). Results show that AGC improves speech intelligibility in studied conditions
• while SSS degrades it
• a result in line with subjective measures found in the literature.

SBrT 2018

This work outlines important characteristics of hybrid PLC-wireless systems for smart grid applications. Moreover, it discusses the hybrid wireless-PLC sys...

• Leonardo de M. B. A. Dib
• Victor Fernandes
• Moisés V. Ribeiro

• Power line communication
• wireless
• hybrid
• smart grid.

SBrT 2016

The increasing demand for rich multimedia services and the scarcity of radio resources has motivated the research of technologies able to increase wireless...

• Henrique de H. M. Barros
• Márzio G. S. Rêgo
• Evilásio O. Lucena
• Tarcisio F. Maciel
• Walter C. Freitas Jr.
• F. Rodrigo P. Cavalcanti

SBrT 2012

it is necessary to perform a proper planning for an efficient deployment of new infrastructure for transmission of digital television in countries that hav...

• J. R. Fernández
• M. Quispe
• G. Kemper
• J. Samaniego
• D. Díaz

• Log-distance path loss model
• field measurements
• digital television
• coverage estimation
• propagation exponent

SBrT 2012

In this paper, we present an admission control scheme for an OFDM (Orthogonal Frequency-Division Multiplexing)/TDMA(Time Division Multiplexing Access) based ...

• Flávio Geraldo Coelho Rocha*
• Flávio Henrique Teles Vieira
• Josemar Alves dos Santos Junior

• Loss probability
• Multifractal Analysis
• Admission Control Scheme

SBrT 2012