Transmitting digital data stream

摘要

The method provides transmission of a digital data signal in an analog television channel. The data signal preferably includes digitally encoded radio programmes and additional serves. the locations of the transmitters for the same channel analog television signal and the digital data signal are identical. The carrier frequency (f1*) of the digital signal is between the image carrier frequency and the colour carrier frequency of the same channel analog television signal. The same channel analog television signal and the digital data signal are transmitted with orthogonal polarisation. The transmitted power of the data signal in all directions is substantially less than that of the same channel analog television signal. As well as terrestrial applications digital signals within the television frequency spectrum can be added to satellite television channels.