Introduction to HD Radio: Notes

This audio system is able to receive standard analog FM/AM radio broadcasting as well as digital HD Radio FM/AM broadcasting.

HD Radio technology provides digital and analog reception using existing FM and AM broadcasting frequencies. Currently, radio stations broadcasting an HD Radio signal are operating in a hybrid mode of both, analog and digital, in order to reach both receivers. In both modes, analog and digital, the broadcasted program contents is the same (except of multicasting, see below).

Eventually, as analog receivers are replaced by digital ones, radio stations may be able to turn off their analog broadcasting and use only the digital one.