Digital Audio Radio - An Application of Audio Compression Technology

Signal compression is a key element in emerging technology for digital audio. Recent AT&T Bell Laboratories algorithms for perceptual audio coding have provided the capability of compressing compact disc (CD) stereo audio at 1,406 kbitskec into rates approximating 128 kbitshec. This capability has enabled the development of new applications in digital audio transmission and broadcasting. In the past few years, Digital Audio Broadcasting - having transmission formats ranging from terrestrial to cable, to satellite - has proven to be a powerful and timely technology through various tests. Many people view that Digital Audio Broadcasting is the logical progression in sound transmission for the next century. Digital Broadcasting's fundamental promises include CD-qualit d and superior immunity to interference. A Digital Audio Broadcasting system also offers the potential of many new broadcast services, including both infor@ation transfer and messaging which can easily be impletnented into digital technology. In this paper, we describe an In-Band Adjacent Chaanel (IBAC) Digital Audio Broadcasting System which was developed at AT&T Bell Laboratories, an ongoing process for creating a Digital Audio Broadcasting standard in United States, and some preliminary laboratory test results of the AT&T IBAC system.