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Sistema de Semáforos Inteligentes (SSI) para Controle de Fluxo de Veículos Automotivos 用于车辆流量控制的智能交通灯系统(SSI)
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42232
G. Ferreira, T. Pereira
– In order to minimize some problems related to car traffic chaos, mainly those concerned to vehicles flux, this paper presents an Intelligent Semaphore System, used to generate better time sequences. The system is based on three main aspects: detection of vehicles, communication between semaphores
为了最大限度地减少与汽车交通混乱有关的一些问题,主要是与车辆流量有关的问题,本文提出了一种智能信号系统,用于生成更好的时间序列。该系统主要基于三个方面:车辆检测、信号之间的通信
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引用次数: 0
Banco de Filtros e Wavelets Cíclicos sobre Corpos de Característica Dois 两个特征域上的滤波器组和循环小波
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42738
G. D. Silva Jr., R. Souza
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引用次数: 0
Performance Analysis of IEEE 802.11n MAC Enhancements over Block Fading Channels 分组衰落信道下IEEE 802.11n MAC增强的性能分析
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.40134
Roger Pierre, Fabris Hoefel
Assuming a Nakagami-m block fading channel, we derive a theoretical medium access control (MAC) and physical (PHY) cross-layer model to estimate the saturation net throughput of IEEE 802.11 wireless local area networks (WLANs) with MAC enhancements. It is analytically shown that these MAC improvements, that consist of modifications of the plain IEEE 802.11 distribution coordination function (DCF) MAC protocol in order to support concatenation and multiframe transmission techniques, allow a substantial improvement of the net throughput.
假设一个Nakagami-m块衰落信道,我们推导了一个理论介质访问控制(MAC)和物理(PHY)跨层模型来估计具有MAC增强的IEEE 802.11无线局域网(wlan)的饱和净吞吐量。分析表明,这些MAC改进,包括修改普通IEEE 802.11分发协调函数(DCF) MAC协议,以支持串联和多帧传输技术,允许大幅提高净吞吐量。
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引用次数: 0
Implementação dos Principais Algoritmos de um Sistema OFDM em Plataforma de Desenvolvimento DSP-FPGA 在DSP-FPGA开发平台上实现OFDM系统的主要算法
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42554
Marcos O. Prates, M. Ribeiro
—This paper aims at to discuss the implementation of the main algorithm of an OFDM system in an Altera‘s DSP-FPGA development platform. First, a brief review about OFDM system is provided, giving an special attention on its basic principles. A introduction on the development board used by the authors is made after that. After that, the implemented OFDM system is detailed. Some results and discussions highlight the potential of DSP-FPGA development platform for multicarrier system implementation.
本文旨在讨论OFDM系统的主要算法在Altera的DSP-FPGA开发平台上的实现。本文首先对OFDM系统进行了简要的综述,重点介绍了OFDM系统的基本原理。然后介绍了作者使用的开发板。然后详细介绍了OFDM系统的实现。一些结果和讨论强调了DSP-FPGA开发平台在多载波系统实现中的潜力。
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引用次数: 0
Avaliação de Desempenho do TCP em Sistemas VBLAST Codificados 编码VBLAST系统中的TCP性能评估
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42487
M. Pellenz, A. Oliveira, R. D. Souza, Manoel Camillo de Oliveira Penna Neto
—The next generation of wireless communications systems will likely incorporate MIMO techniques in order to provide higher data rate multimedia services. Moreover, the transmission control protocol (TCP) is generally employed at the transport layer for reliable data communication. Thus, the optimization of TCP performance over MIMO systems is currently an important research area. In this paper
——下一代无线通信系统可能会采用MIMO技术,以提供更高的数据速率多媒体服务。此外,在传输层通常采用传输控制协议(TCP)来实现可靠的数据通信。因此,MIMO系统中TCP性能的优化是当前一个重要的研究领域。在本文中
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引用次数: 0
Estudo de estimadores de Impulsividade em Amostras de Sinais de Comunicações 通信信号样本中脉冲估计量的研究
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42897
E. Ferraz, R. Coelho
Resumo— Nota-se cada vez mais a presenca de fenomenos impulsivos ou de cauda-pesada em diferentes areas, o que sugere que estes nao possam ser mais modelados como se fossem Gaussianos. Ao mesmo tempo, a modelagem destes processos como nao-Gaussianos motiva a necessidade de uma melhor caracterizacao dos parâmetros que os definem. Neste trabalh o, foram estudados e avaliados os metodos de McCulloch e o QQ plot que estimam impulsividade e indice de cauda. Alem disso, foi proposto um metodo que transpoe as restricoes dos dois primeiros. Os estimadores foram aplicados em sequencias amostrais obtidas de comunicacoes moveis e tambem de geracao de amostras com distribuicoes Pareto e �-estaveis. Palavras-Chave— Processos de cauda-pesada, processos �estaveis, impulsividade, metodo de McCulloch, QQ plot.
摘要:越来越多的冲动或重尾现象出现在不同的区域,这表明它们不能再被建模为高斯现象。同时,将这些过程建模为非高斯过程,需要更好地描述定义它们的参数。本文研究和评价了McCulloch方法和QQ图估计冲动性和尾指数。此外,还提出了一种克服前两种限制的方法。这些估计器被应用于从移动通信中获得的样本序列,以及具有帕累托和稳定分布的样本生成。关键词:重尾过程,稳定过程,冲动性,麦卡洛克方法,QQ图。
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引用次数: 0
Rádio Cognitivo como um Meio de Aumentar a Capacidade de Redes em Malha sem Fio 认知无线电作为一种增加无线网状网络容量的手段
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42362
R. C. Pereira, R. D. Souza, M. Pellenz
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引用次数: 0
Probabilidade de Erro de Bit em Receptor MRC com Modulação QAM sob Desvanecimento Generalizado: Parte II 广义衰落下QAM调制MRC接收机的位错概率:第二部分
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42825
W. Queiroz, Francisco Madeiro Bernardino Junior, M. Alencar
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引用次数: 0
Projeto e Otimização de Redes TCP/IP com o Dimensionamento de Enlaces e Buffers com Garantia de Qualidade de Serviço TCP/IP网络的设计和优化,链路和缓冲区的大小,保证服务质量
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42783
C. R. C. Bento, E. Wille
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引用次数: 0
Uma Arquitetura em Dois Niveis para o Suporte de Comunicação de Tempo-Real em Redes CSMA 支持CSMA网络实时通信的两级架构
Pub Date : 1900-01-01 DOI: 10.14209/sbrt.2008.42527
R. Moraes, F. Vasques, Paulo Portugal
In this paper, a new approach to support real-time (RT) communication in IEEE 802.11 networks is proposed. It is based on a 2-tier architecture. In the lower layer (MAC layer), a forcing collision resolution mechanism enforces a higher priority level to the RT stations. In the upper layer, a coordination mechanism ensures a collision-free access among the set of RT stations. The proposed architecture prioritizes the RT traffic over non-RT traffic, without the need to strictly control the timing behavior of every communication device.
本文提出了一种在IEEE 802.11网络中支持实时通信的新方法。它基于两层架构。在较低的层(MAC层),强制冲突解决机制强制RT站具有更高的优先级。在上层,协调机制确保RT站集之间的无冲突访问。提出的体系结构优先考虑RT流量而不是非RT流量,而不需要严格控制每个通信设备的定时行为。
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引用次数: 0
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Anais do XXVI Simpósio Brasileiro de Telecomunicações
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