Radiodifusão Local na Faixa de 26 MHz Usando DRM: Resultados de Testes em Brasília

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The digitalization of the sound broadcasting systems is currently underway throughout the world. One of the systems available for such a process is Digital Radio Mondiale (DRM), which is currently designed to operate in frequencies below 30 MHz. Through the use of the DRM system, a much higher audio quality can be achieved than that of AM radio with the use of 10 or 20 kHz wide channels. One interesting application of this system is local broadcasting in the 26 MHz band (25.67 to 26.1 MHz), using line-of-sight propagation in a way similar to that used in VHF, with frequency modulated signals. The 26 MHz band is traditionally used for long range transmission through ionospheric reflection. However, this propagation method is not effective in most of the time of the 11 year sunspot cycle. Therefore it is nowadays scarcely used. A test campaign was carried out in Brasilia in the attempt to better evaluate the performance of the DRM system for local broadcasting in the 26 MHz band and consequently the viability of such an application. This dissertation describes those tests and the results obtained. There was a clear indication that the 26 MHz DRM signal can achieve a reception area similar to that of a FM/VHF signal using a much lower radiated power. Nevertheless, audio dropouts can occur in the mobile reception performed in the boundaries of the reception area or in locations where the signal received experiences strong variations caused by multipath propagation. Some complementary tests, as well as some long-term tests, should be made in order to better endorse this broadcasting strategy.

ASSUNTO(S)

telecomunicacoes radiodifusão - 26 mhz testes de campo radiodifusão sonora digital sistema drm

ACESSO AO ARTIGO

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