M. J. D. Sousa, L. V. D. Souza, C. Sales, R. D. Silva, J. C. Chamma, C. Francês, J. W. A. Costa
{"title":"Otimização de Grades de Bragg em Fibra Usando Processamento Paralelo e Algoritmo Genético","authors":"M. J. D. Sousa, L. V. D. Souza, C. Sales, R. D. Silva, J. C. Chamma, C. Francês, J. W. A. Costa","doi":"10.14209/sbrt.2003.348","DOIUrl":"https://doi.org/10.14209/sbrt.2003.348","url":null,"abstract":"","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"73 1 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":"123599299","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}
F. Barbosa, M. C. Rosa, C. A. Gonçalves, F. G. V. Resende Jr.
{"title":"Algoritmo para Leitura de Siglas em um Sintetizador de Voz","authors":"F. Barbosa, M. C. Rosa, C. A. Gonçalves, F. G. V. Resende Jr.","doi":"10.14209/sbrt.2003.671","DOIUrl":"https://doi.org/10.14209/sbrt.2003.671","url":null,"abstract":"","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"5 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":"121946504","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}
— Two different iterative receivers for space-time cod- ed data transmitted through frequency selective fading channels are analyzed. We compare the two schemes in terms of bit error rate and computational effort. Our results show that, in many cases, the supertrellis approach for combined detection and decoding can be a better compromise solution than the separate approach
{"title":"Receptores Iterativos Semi-Cegos para Modulação Codificada Espácio-Temporal e Canais Seletivos Quasi-Estáticos","authors":"R. D. Souza, J. Garcia-Frias","doi":"10.14209/sbrt.2003.322","DOIUrl":"https://doi.org/10.14209/sbrt.2003.322","url":null,"abstract":"— Two different iterative receivers for space-time cod- ed data transmitted through frequency selective fading channels are analyzed. We compare the two schemes in terms of bit error rate and computational effort. Our results show that, in many cases, the supertrellis approach for combined detection and decoding can be a better compromise solution than the separate approach","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"20 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":"124874692","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}
{"title":"Códigos Convolucionais Espácio-Temporais sobre GF(p) Atingindo Ganho de Diversidade Máximo para Qualquer Número de Antenas Transmissoras","authors":"M. Noronha-Neto, B. Uchôa-Filho","doi":"10.14209/sbrt.2003.267","DOIUrl":"https://doi.org/10.14209/sbrt.2003.267","url":null,"abstract":"","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"114 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":"124067564","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}
{"title":"Receptores Multiusuário MMSE com Posto Reduzido para DS-CDMA usando Filtros FIR Interpolados","authors":"R. D. Lamare, R. Sampaio Neto","doi":"10.14209/sbrt.2003.454","DOIUrl":"https://doi.org/10.14209/sbrt.2003.454","url":null,"abstract":"","PeriodicalId":325953,"journal":{"name":"Anais do XX 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":"120963867","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}
| In this paper we show a procedure for coding geodesics on modular surfaces by use of the Elias type of code for source coding. This procedure implies that the arithmetic codes associated with each primitive hyperbolic matrix can be viewed as a generalization of the Elias codes. The main result of this paper establishes the procedures to be followed in order to identify the arithmetic code and the axis of the geodesic when only the probability associated with the geodesic is given. Several examples are also considered.
{"title":"Coding Closed Geodesics on Modular Surfaces by Use of the Elias Type of Codes","authors":"R. Palazzo Jr., M. F. D. Silva, H. Lazari","doi":"10.14209/sbrt.2003.310","DOIUrl":"https://doi.org/10.14209/sbrt.2003.310","url":null,"abstract":"| In this paper we show a procedure for coding geodesics on modular surfaces by use of the Elias type of code for source coding. This procedure implies that the arithmetic codes associated with each primitive hyperbolic matrix can be viewed as a generalization of the Elias codes. The main result of this paper establishes the procedures to be followed in order to identify the arithmetic code and the axis of the geodesic when only the probability associated with the geodesic is given. Several examples are also considered.","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"323 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":"124565909","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}
C. Bastos Filho, S. C. Oliveira, E. Arantes, J. F. Martins Filho
- We propose and demonstrate a novel dynamic routing algorithm (RWA) for transparent optical networks based on physical layer impairments such as switch loss, amplifier noise accumulation, amplifier gain saturation, amplifier bandwidth, wavelength dependent gain and device losses along lightpaths. Also, we study the influence of each impairment related to the amplifiers and switch elements, on the network performance. The metrics of our algorithm is based on the calculation of the noise figure using the well known formulation for cascade of elements in lightpaths. We assume no wavelength conversion capabilities in our network and we assign wavelengths using a first fit algorithm. For a given call our algorithm assigns the first available wavelength and calculates the best route (minimum noise figure). Upon the calculation of the noise figure of the lightpath we obtain the bit error rate (BER). Our algorithm blocks a call if there is no wavelength available or if the BER for the available wavelength is above a given level, which guarantees a pre-defined quality-of-service for the network operation. We present simulation results of dynamic traffic in a hypothetical meshed network in terms of blocking probabilities as a function of the available wavelengths number, switch loss, network load and amplifier characteristics. We demonstrate that our algorithm outperforms the traditional shortest path routing algorithm.
{"title":"Impact of Optical Switch and Amplifier Characteristics on Physical Impairment-based Wavelength -Routed Optical Networks","authors":"C. Bastos Filho, S. C. Oliveira, E. Arantes, J. F. Martins Filho","doi":"10.14209/sbrt.2003.126","DOIUrl":"https://doi.org/10.14209/sbrt.2003.126","url":null,"abstract":"- We propose and demonstrate a novel dynamic routing algorithm (RWA) for transparent optical networks based on physical layer impairments such as switch loss, amplifier noise accumulation, amplifier gain saturation, amplifier bandwidth, wavelength dependent gain and device losses along lightpaths. Also, we study the influence of each impairment related to the amplifiers and switch elements, on the network performance. The metrics of our algorithm is based on the calculation of the noise figure using the well known formulation for cascade of elements in lightpaths. We assume no wavelength conversion capabilities in our network and we assign wavelengths using a first fit algorithm. For a given call our algorithm assigns the first available wavelength and calculates the best route (minimum noise figure). Upon the calculation of the noise figure of the lightpath we obtain the bit error rate (BER). Our algorithm blocks a call if there is no wavelength available or if the BER for the available wavelength is above a given level, which guarantees a pre-defined quality-of-service for the network operation. We present simulation results of dynamic traffic in a hypothetical meshed network in terms of blocking probabilities as a function of the available wavelengths number, switch loss, network load and amplifier characteristics. We demonstrate that our algorithm outperforms the traditional shortest path routing algorithm.","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"280 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":"121367206","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}
{"title":"Desempenho de Algoritmos de Sincronização para Sistemas OFDM em Canais de HF","authors":"C. P. D. Albuquerque, E. Pinto","doi":"10.14209/sbrt.2003.659","DOIUrl":"https://doi.org/10.14209/sbrt.2003.659","url":null,"abstract":"","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"8 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":"122716905","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}
{"title":"The Semidirect Product Z2 by a Finite Group S is Bad for Non Abelian Codes","authors":"J. Arpasi","doi":"10.14209/sbrt.2003.338","DOIUrl":"https://doi.org/10.14209/sbrt.2003.338","url":null,"abstract":"","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"23 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":"124009472","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}
L. G. D. Sousa, M. R. Albuquerque, S. G. D. Silva, A. d'Assunção
{"title":"Antenas de Microfita Suspensas com Dielétricos em Rampa","authors":"L. G. D. Sousa, M. R. Albuquerque, S. G. D. Silva, A. d'Assunção","doi":"10.14209/sbrt.2003.538","DOIUrl":"https://doi.org/10.14209/sbrt.2003.538","url":null,"abstract":"","PeriodicalId":325953,"journal":{"name":"Anais do XX Simpósio Brasileiro de Telecomunicações","volume":"24 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":"127235477","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}
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