Date of Award
Master of Science in Electrical Engineering - (M.S.)
Electrical and Computer Engineering
Ali N. Akansu
This thesis examines the in-band on-channel transmission of digital audio data for application in Digital Audio Broadcasting (DAB). The premise is to use the existing FM channels for transmission of DAB. For the FM channel used for analog audio transmission, two different scenarios are suggested and investigated.
In the first scenario, to enable overlay of the new DAB and current FM transmissions, the digital data is modulated by a direct sequence spread spectrum signal to bring the average transmitted power below that of the FM signal using the same channel. The FM signal interferes with the digital transmission and it needs to be excised before the digital signal can be decoded. Different excision techniques, such as a fixed subband-based exciser, an adaptive subband-based exciser, and a Binomial-Gaussian window-based exciser, are suggested and their performances evaluated.
The second FM scenario involves transmitting the digital audio data as an AM modulation on the FM signal. Since the FM receiver evaluates the phase information only, the additional envelope modulation does not interfere with the analog FM service.
In addition to the FM channel investigation, a preliminary analysis of the use of the AM channel for digital overlay transmission is presented.
Meyer, Michael, "AM/FM digital audio broadcasting in-band on-channel transmission" (1994). Theses. 1564.