Navegando por Assunto "ADSL - Asymetric digital subscriber line"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Hermes: um software-modem ADSL baseado no framework Ptolemy II
(Universidade Federal do Pará, 2011-04-20) GUEDES, Gustavo Cunha; KLAUTAU JÚNIOR, Aldebaro Barreto da Rocha; http://lattes.cnpq.br/1596629769697284
This dissertation has as main objective to present the implementation of an ADSL software-modem totally written in Java, using the Ptolemy II framework, named Hermes (from \A Handy Experimental softwaRe ModEm System"). A software-modem is useful in cases where one needs to perform tests and simulations of communication systems with a large number of modems and when systems' parameters must be changed with high degree of freedom. Besides, a software-modem has features that make it easy to add, eliminate, validate and evaluate signal processing and telecommunications functions and algorithms. Tests and simulations were performed to evaluate the Hermes functionality, including the use of Tracespan, a non-intrusive analisys equipment for DSL networks. From obtained results together with Tracespan, it was possible to successfully validate the Hermes functions.
Acesso aberto (Open Access)
Implementação em software da codificação de canal em ADSL: um estudo de caso sobre os efeitos do ruído impulsivo na transmissão de vídeo
(Universidade Federal do Pará, 2011-03-25) CORRÊA, Fernanda Regina Smith Neves; KLAUTAU JÚNIOR, Aldebaro Barreto da Rocha; http://lattes.cnpq.br/1596629769697284; PELAES, Evaldo Gonçalves; http://lattes.cnpq.br/0255430734381362
This work describes the implementation in software of the channel coding used in the ADSL standard. The theory of channel coding is described, as well as the channel coding implemented in the Software Modem ADSL using the development environment Ptolemy II. The implementation of a impulsive noise model is also presented. To ensure that the implementation meets the ADSL standard, tests using the DSL systems analyzer TraceSpan are described. This work also presents an application example of the Software Modem ADSL, characterized by a study case on the e ects of impulsive noise in the video transmission, analyzing the impact of some parameters of channel coding in the correction of errors.