Pub Date : 1900-01-01DOI: 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
{"title":"Sistema de Semáforos Inteligentes (SSI) para Controle de Fluxo de Veículos Automotivos","authors":"G. Ferreira, T. Pereira","doi":"10.14209/sbrt.2008.42232","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42232","url":null,"abstract":"– 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","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121466416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.14209/sbrt.2008.42738
G. D. Silva Jr., R. Souza
{"title":"Banco de Filtros e Wavelets Cíclicos sobre Corpos de Característica Dois","authors":"G. D. Silva Jr., R. Souza","doi":"10.14209/sbrt.2008.42738","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42738","url":null,"abstract":"","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127538944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 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.
{"title":"Performance Analysis of IEEE 802.11n MAC Enhancements over Block Fading Channels","authors":"Roger Pierre, Fabris Hoefel","doi":"10.14209/sbrt.2008.40134","DOIUrl":"https://doi.org/10.14209/sbrt.2008.40134","url":null,"abstract":"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.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133729597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 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.
{"title":"Implementação dos Principais Algoritmos de um Sistema OFDM em Plataforma de Desenvolvimento DSP-FPGA","authors":"Marcos O. Prates, M. Ribeiro","doi":"10.14209/sbrt.2008.42554","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42554","url":null,"abstract":"—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.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"324 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133139330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 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
{"title":"Avaliação de Desempenho do TCP em Sistemas VBLAST Codificados","authors":"M. Pellenz, A. Oliveira, R. D. Souza, Manoel Camillo de Oliveira Penna Neto","doi":"10.14209/sbrt.2008.42487","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42487","url":null,"abstract":"—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","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133997134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 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.
{"title":"Estudo de estimadores de Impulsividade em Amostras de Sinais de Comunicações","authors":"E. Ferraz, R. Coelho","doi":"10.14209/sbrt.2008.42897","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42897","url":null,"abstract":"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.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122432043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.14209/sbrt.2008.42362
R. C. Pereira, R. D. Souza, M. Pellenz
{"title":"Rádio Cognitivo como um Meio de Aumentar a Capacidade de Redes em Malha sem Fio","authors":"R. C. Pereira, R. D. Souza, M. Pellenz","doi":"10.14209/sbrt.2008.42362","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42362","url":null,"abstract":"","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128821506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.14209/sbrt.2008.42825
W. Queiroz, Francisco Madeiro Bernardino Junior, M. Alencar
{"title":"Probabilidade de Erro de Bit em Receptor MRC com Modulação QAM sob Desvanecimento Generalizado: Parte II","authors":"W. Queiroz, Francisco Madeiro Bernardino Junior, M. Alencar","doi":"10.14209/sbrt.2008.42825","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42825","url":null,"abstract":"","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128757826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.14209/sbrt.2008.42783
C. R. C. Bento, E. Wille
{"title":"Projeto e Otimização de Redes TCP/IP com o Dimensionamento de Enlaces e Buffers com Garantia de Qualidade de Serviço","authors":"C. R. C. Bento, E. Wille","doi":"10.14209/sbrt.2008.42783","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42783","url":null,"abstract":"","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114591897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 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.
{"title":"Uma Arquitetura em Dois Niveis para o Suporte de Comunicação de Tempo-Real em Redes CSMA","authors":"R. Moraes, F. Vasques, Paulo Portugal","doi":"10.14209/sbrt.2008.42527","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42527","url":null,"abstract":"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.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116237197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}