An?lise da propaga??o de ondas eletromagn?ticas em canais com desvanecimento

Detalhes bibliográficos
Ano de defesa: 2002
Autor(a) principal: Mendon?a, Lara de Almeida lattes
Orientador(a): Ribeiro, Jos? Ant?nio Justino lattes
Banca de defesa: Ribeiro, Jos? Ant?nio Justino lattes, Cortez, Jose Antonio lattes, Silveira, Mauricio lattes
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Instituto Nacional de Telecomunica??es
Programa de Pós-Graduação: Mestrado em Engenharia de Telecomunica??es
Departamento: Instituto Nacional de Telecomunica??es
País: Brasil
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: http://tede.inatel.br:8080/tede/handle/tede/102
Resumo: A very important problem in radio communication systems is the fluctuation in received signal level, caused by several factors that affect the electromagnetic waves propagation. The phenomenon is called fading and among it?s most important causes one can mention the received signal combination from multipath between the transmitter and the receiver, changes at the environment propagation characteristics, and so on. Frequently, the compound signal at the reception antenna results in combinations that does not obey a predictable law, once the responsible factors over the link depend on propagation conditions, associated to meteorological and environmental effects. To create a reliable system project and installation it is necessary the exact knowledge of several mechanisms which degrade the signal, aiming to provide some ways to compensate them. In this study, it will be analyzed the signal behavior in an environment that helps this effect to appear. It will be discussed the statistical distributions that can estimate the random signal fluctuation. Laboratory simulations will be realized to certify the link behavior under fading presence. The detrimental effects of the system quality with digital modulation are emphasized.