HD Radio

HD Radio is a trademarked term for iBiquity's in-band on-channel (IBOC) digital radio technology used by AM and FM radio stations to transmit audio and databy using a digital signal embedded “on-frequency” immediately above and below a station's standard analog signal, providing the means to listen to the same program in either HD (digital radio with less noise) or as a standard broadcast (analog radio with standard sound quality). The HD format also provides the means for a single radio station to simultaneously broadcast one or more different programs in addition to the program being transmitted on the radio station's analog channel.Digital information is transmitted using OFDM with an audio compression algorithm called HDC (High-Definition Coding). (HDC is a proprietary codec based upon, but incompatible with, the MPEG-4 standard HE-AAC).