Análise do desempenho do sistema brasileiro de TV digital sob condições adversas de recepção

• Autor(a) principal: Ono, Danillo
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: http://dspace.mackenzie.br/handle/10899/24406
• topic: recepção com antena interna; TV digital; multipercursos; efeito Doppler; testes de campo, SBTVD (Sistema Brasileiro de Televisão Digital); indoor reception; digital TV; multipaths; Doppler effect; field tests; SBTVD (Sistema Brasileiro de Televisão Digital); CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA

The main objective of this work is to study and evaluate the reception s conditions of a Digital TV signal, modulated in Brazilian standard and received with the use of an internal and external antenna, to analyze and to study the interferences that affect it. Comparing the conditions for receipt of the theoretical model of Okumura Hata with real data collected in field tests. Field tests are carried out at several points of Sao Paulo city, to collect data that will be analyzed later. It will use a process of RF capturing, where digital signals are stored on a hard-disk and through the use of laboratory equipments, and through the help of softwares such as Matlab and EDX, data are analyzed taking up account of their impulsive response, the amount of multipaths present in the signal and sensibility to the doppler effect. It was chosen Sao Paulo city because it presents very adverse conditions of reception when compared to other cities in the world, due to its large amount of buildings and antennas, which generate many multipaths. The presence of a large amount of old cars and old appliances, generate impulsive noise. Brazil has the second largest fleet of helicopters in the world and also the large amount of aircrafts flying over the skies of the city, affecting the signals with doppler effect. About 90% of the population that attends TV, use some kind of antenna, which does them receive signals affected by these kind of interference.