{"id":1557,"date":"2010-09-23T08:47:31","date_gmt":"2010-09-23T12:47:31","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=3928"},"modified":"2023-07-26T17:16:21","modified_gmt":"2023-07-26T21:16:21","slug":"digital-radio-mondiale-an-alternative-to-hd-radio","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2010\/09\/digital-radio-mondiale-an-alternative-to-hd-radio\/","title":{"rendered":"Digital Radio Mondiale, an alternative to HD radio?"},"content":{"rendered":"
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\"DRM<\/a><\/figure>\n<\/div>\n\n\n

Could be. \u00a0\u00a0Digital Radio Mondiale<\/a>, or DRM<\/a>, is a modulation scheme that a group of broadcasters and transmitter manufacturers have been working on since about 1997 or so. \u00a0There are numerous shortwave broadcasters; the BBC<\/a>, the CBC<\/a>, Deutsche Welle<\/a>, Radio France Internationale<\/a>, the VOA<\/a>, and others have been using DRM on shortwave for several years now. \u00a0I can state that the shortwave DRM system works well, I have a software decoder and use the sound card input on my computer to decode and listen to DRM shortwave broadcasts.<\/p>\n\n\n\n

The goal of DRM is to establish a worldwide open standard for digital broadcasting in the LF, MF, HF, and VHF bands. \u00a0In the early years of development, \u00a0DRM was designed for digital broadcasting on bands below 30 MHz. \u00a0This system is now known as DRM30. \u00a0Since then, the DRM consortium has expanded that to the VHF band (up to 174 MHz) \u00a0as well (meaning where the current FM band is located) and has called that system DRM+.<\/p>\n\n\n\n

DRM uses\u00a0COFDM<\/a> (Coded Orthogonal Frequency Division Multiplex) modulation, which is the same as IBOC HD radioTM<\/sup>. \u00a0This is a robust modulation system that employs multiple carriers at lower power (than an analog carrier) spread across the entire allotted bandwidth.<\/p>\n\n\n\n

One of the claims is \u00a0DRM transmits less power and is more energy efficient. \u00a0In general, digital radio modulation does transmit less power, that is true. \u00a0However, transmitters have to be run more linearly for digital due to the increased bandwidth. \u00a0This may not translate to greatly increased efficiency from the AC mains to RF standpoint. \u00a0Because of that, there is more waste heat, and thus more air conditioning is needed to cool the transmitter room.<\/p>\n\n\n\n

Some of the advantages of DRM over Ibiquity’s HD radioTM<\/sup> are:<\/p>\n\n\n\n