Patent ID: 10069659

Abstract:
Embodiments of a noise-shaping crest factor reduction method for a carrier signal (and a device that performs the method) include (a) clipping the carrier signal by selecting at least one carrier signal peak that has a magnitude exceeding a predetermined crest factor reduction threshold, (b) subtracting the resulting clipped signal from the carrier signal, (c) confining, by a noise shaping filter, the resulting clipping noise signal in a frequency band corresponding to that of the carrier signal, and (d) subtracting the resulting spectrally shaped clipping noise signal from a delayed version of the carrier signal. The confining process includes selecting first sub-areas of the noise shaping filter response at one or more guard bands, selecting at least one second sub-area of the noise shaping filter response elsewhere in the frequency band, and setting the first sub-areas to a first predetermined magnitude higher than the magnitude of the second sub-area.