Sensoriamento Espectral Baseado em Testes de Normalidade

Jerônimo Silva Rocha, Marcelo Sampaio de Alencar e José, Ewerton P. de Farias

DOI: 10.14209/sbrt.2013.232

Keywords: Spectrum Sensing Normality Tests Cognitive Radios

Abstract

Spectrum Sensing is studied to determine if a signal, measured by a cognitive user in an AWGN channel, results from the primary user or if is composed by noise one. The proposed method for spectrum sensing is based on normality tests. The results of Monte-Carlo simulations indicate that it is possible to identify transmission opportunities through spectrum sensing tests, with probability of detection of 0.9 for a signal to noise ratio around -17 dB and a probability of false alarm of 0.01

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Transcoding Analysis of a Digital Video Archive

Itapajé Takeguma, Bruno Wanderley

DOI: 10.14209/sbrt.2013.227

Keywords: Transcoding video archive H.264/AVC

Abstract

Digital video presents a great challenge for any entity responsible for its archival: huge amount of data to be stored. This paper presents an empirical research that was conducted aiming to evaluate the introduction of the transcoding technique and the H.264/AVC encoding to the video archival system maintained at Brazilian Senate. Image quality issues were considered, besides storage reduction, but there was no study of audio degradation or CPU cost

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Energy Efficiency Optimization in MPG DS/CDMA

Mateus de Paula Marques, Lucas D. H. Sampaio, Fernando Ciriaco, Fábio R. Durand, Taufik Abrão

DOI: 10.14209/sbrt.2013.233

Keywords: Resource allocation energy-efficient design ant colony optimization CDMA particle swarm optimization

Abstract

In this contribution, the heuristic continuous ant colony optimization (ACO) algorithm is deployed to solve the energy-efficiency (EE) optimization problem in multirate multiprocessing gain (MPG) DS/CDMA network. The EE design deal with quasi-concave energy efficiency function, allowing the system to operate in the maximal energy efficiency point. Numerical results considering realistic wireless mobile channels and system operation conditions have been shown the applicability of the ACO heuristic approach in order to solve hard problems (in many cases non-convex optimization problems) with practical interest in obtaining energy-efficient design, which is of great interest to establish the next wireless generation green communication networks. The performance and complexity of the proposed ACOheuristic approach are compared with other two procedures, a heuristic approach based on particle swarm optimization (PSO) and the disciplined convex optimization approach (CvX) tools.

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Real-time Aircraft Telemetry using Wireless Sensor Network

Rodolfo Rodrigues de Sousa, Cintia Borges Margi

DOI: 10.14209/sbrt.2013.228

Keywords: Telemetry aircraft wireless sensor networks

Abstract

This paper descirbres the design of a real time monitoring system based on wireless sensor networks aiming to measure accelerations, airspeed, spacial orientation and geographical position of a radio-controlled aircraft in order to allow their designers (university students) to measure how their planes performed. We use a Microsoft .NET Gadgeteer board connected to sensor, a SD card and XBee radio module, and a visualization software on ground to decipt the airplane characteristics while on flight. After specification and implementation, individual tests were realized with sensors , as well as and in-flight test.

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Reuso da Portadora Óptica em Altas Taxas com Amplificador Óptico a Semicondutor Ultra Longo

Napoleão S. Ribeiro, Cristiano M. Gallep, Evandro Conforti

DOI: 10.14209/sbrt.2013.234

Keywords: amplificadores ópticos a semicondutor redes ópticas de acesso reuso da portadora óptica.

Abstract

Apresentam-se resultados experimentais de reuso de portadora óptica para possíveis aplicações em redes de acesso ópticas. A portadora, inicialmente modulada em altas taxas (sinal downstream, < 50 Gb/s) foi remodulada em 3,8 Gb/s (sinal upstream ). A técnica de reuso é baseada na saturação do ganho de um amplificador óptico a semicondutor ultra-longo (ULSOA). A influência da taxa de modulação e da razão de extinção do sinal downstream na qualidade do sinal upstream é investigada. As penalidades apresentadas são inferiores a 1 dB, excetuando-se os casos de elevada razão de extinção do sinal downstream.

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Time-of-Flight Selection for Improved Acoustic Sensor Localization Using Multiple Loudspeakers

Wallace A. Martins, Leonardo O. Nunes, Diego B. Haddad, Luiz W. P. Biscainho, Bowon Lee., Markus V. S. Lima, Maur´ıcio do V. M. da Costa

DOI: 10.14209/sbrt.2013.229

Keywords: Acoustic sensor localization time-of-flight leastsquares reverberation noise estimation

Abstract

Wallace A. Martins, Leonardo O. Nunes, Diego B. Haddad, Luiz W. P. Biscainho, Markus V. S. Lima, Maur´ıcio do V. M. da Costa, Bowon Lee.

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Sensoriamento Espectral com Fusão de Autovalores para Sinais sob Desvanecimento Rápido

Carlos R. N. da Silva, Dayan A. Guimarães, Rausley A. A. de Souza

DOI: 10.14209/sbrt.2013.235

Keywords: Cognitive Radio cooperative sensing spectrum sensing mobile communication systems

Abstract

Cognitive Radio, cooperative sensing, spectrum sensing, mobile communication systems

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Protótipo para Sensoriamento Espectral Cooperativo Centralizado com Transceptor WaveRunner

Dayan Adionel Guimarães, Danielle de Carvalho Marchetti, Rausley Adriano Amaral de Souza

DOI: 10.14209/sbrt.2013.230

Keywords: Cognitive radio energy detection spectrum sensing VisSim/Comm WaveRunner transceiver.

Abstract

This paper describes a testbed prototype implemented with the WaveRunner transceiver card and the VisSim/Comm software for the purpose of spectrum sensing, as an alternative to the commonly-adopted solutions based on the USRP & GNU Radio. The testbed applies the energy detection in a data fusion, centralized cooperative spectrum sensing with up to eight cognitive radios. The prototype demonstrates the feasibility of the cooperative spectrum sensing for cognitive radio applications in a Rayleigh fading channel with the WaveRunner card. It is also demonstrated that the prototype can be modified to consider other techniques besides the energy detection.

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Solução de Plataforma LTE para eNodeB

Rafael M. Vilela, José A. Bianco, Felipe Figueiredo, Fabrício Lira, Romeu P. de Gouvêa, Fabbryccio Cardoso

DOI: 10.14209/sbrt.2013.236

Keywords: LTE LTE-A LTE Baseband Plataform Radio Protocol Stack FPGA

Abstract

This article presents a Baseband implementation proposal for LTE eNodeB. The hardware solution is based on a chipset with one FPGA Xilinx Virtex6 XC6VLX240T and one general purpose processor Intel i7. This work is focused on the firmware development for the physical layer using the FPGA device. Implementation aspects, validation strategy and architecture are also shared in this article.

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BGP Traffic Engineering: Understanding South America Traffic Patterns to improve decision-making

Márcio A. de Deus, Paulo H. P. Carvalho, João Paulo Leite

DOI: 10.14209/sbrt.2013.214

Keywords: Internet Traffic BGP policies BGP Traffic Engineering Characterization Forecasting Decision Maker

Abstract

The importance of the traffic control is a huge paradigm on the Internet. The AS by definition assumes no external control, this could be an enourmous problem when the traffic is asymmetric and the inbound is the higher portion. The problem is very often in networks hosted in South America countries because their high level dependence to North American ASes. Some real South America networks will be analyzed, characterized to help in Decision-Making.

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