Digital Audio Broadcasting

Kuh, S. and Wang, J. Communications systems engineering for digital audio broadcast. In Proceedings of the 45th Anniud Broadcast Engineering Conference, National Association of Broadcasters, 1991, pp. 267-272. 

First Report and Order to Mass Media Docket No. 99-325, Digital Audio Broadcasting Systems and Their Impact on the Terrestrial Radio Broadcast Service, Federal Communications Commission, Washington, D.C., 2002. 

Smyth, S. 1992. Digital audio data compression. Broadcast Engineering (Feb.) 52-60. 

Smyth, S. Digital audio data compression. Broadcast Engineering Magazine, pp. 52-60, Feb. 1992. Springer, K.D. Interference between EM and Digital M-PSK Signals in the EM Band, National Association of Broadcasters, 1992. 

So, we get 2 1 compression by lowering the sample rate (44 kHz > 22 kHz) and another 11 1 compression from the MP3 codec. Where does this major 11 1 compression come from This is the heart of any compression format and is where the differences between the various formats will emerge. It is also where audible artifacts creep into the signal. Claiming that the audio is equivalent to FM radio is a bit disingenuous, since a broadcast FM radio signal is not digitally compressed. This is not to pick on the MP3 format—all compressed formats claim compression that is equivalent to CD-quality or FM-quality and so on, but these references refer only to the sample rate, bit depth, and the arithmetic—not to the actual what-you-hear quality. 

Convert each of the following quantities into energies, in kcal mol . (a) A bond rotation of 750 wavenumbers (cm ) (b) a bond vibration of 2900 wavenumbers (cm ) (c) an electronic transition of 350 nm (ultraviolet light, capable of sunburn) (d) the broadcast frequency of the audio signal of TV channel 6 (87.25 MHz before the advent of digital TV in 2009) (e) a hard X-ray with a 0.07-nm wavelength. 

High-frequency (HF) radio broadcasts occupy the radio spectmm from 3 to 30 MHz. These signals are commonly used for time and frequency transfer at moderate performance levels. Some HF broadcasts provide audio time announcements and digital time codes. Other broadcasts simply provide a carrier frequency for use as a reference. 

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