How is the IBOC signal different from the FM signal?
The IBOC signal includes an amplitude component in the RF waveform that requires linear amplification. This means that during the transmission process, the IBOC transmitter must preserve the original signal’s amplitude and phase adding nothing to it (i.e., distortions) and subtracting nothing from it, from input through amplification through output. Signal linearity is essential for two reasons: first, to maintain coverage, and second, to ensure compliance with the FCC’s RF spectral mask to prevent interference.
