DRM DIGITAL BROADCASTING SYSTEM AUDIO PATH QUALITATIVE CHARACTERISTICS

Abstract

The Digital Radio Mondiale (DRM) digital broadcasting system is the only ITU-approved digital broadcasting system for the LF, MF and HF bands. Numerous theoretical and field studies, as well as operating experience over the past 20 years, have allowed a good study of digital broadcasting networks organization according to this standard. However, some of the issues related to the audio path formal characteristics were not considered. The article discusses the audio coders used in the DRM system and the available data rates in various immunity modes. A set of test signals for instrumental measurements and listening has been developed. The results of experimental measurements for various data rates are presented. It is shown that the range of modulating frequencies in 7 modes of immunity is not narrower than for FM transmitters. In another 5 modes of noise immunity, the range of modulating frequencies is narrower than for FM transmitters, but wider than for AM transmitters. It is confirmed that at data rates of more than 16.5 kbps, the DRM transmitter signal quality becomes no worse than AM signal transmitter quality. Above 24 kbps, the DRM transmitter signal quality becomes comparable to that of an FM transmitter.