A technique for Crest Factor reduction and amplitude pre-distortion of
multi-carrier signals is described. The input to the multi-carrier
amplifier is modified by a Crest Factor reduction and amplitude
pre-distortion circuit, prior to being applied to the amplifier. The
Crest Factor reduction and amplitude pre-distortion circuit first clips
the amplitude of the signal, converts the clipped signal to baseband to
produce the baseband representative of each carrier, filters each
baseband representative to remove the unwanted signals, up converts each
baseband representative to its multi-carrier baseband frequency and
finally the up converted signals are combined to produce the
multi-carrier baseband signal. The Crest Factor reduction and amplitude
pre-distortion circuit next pre-distort the amplitude of the signal using
a look up table before applying the signal to the amplifier. The main
signal input to the Crest Factor reduction and amplitude pre-distortion
circuit could be a baseband, an intermediate frequency (IF) or radio
frequency (RF) signal. The feedback signal to Crest Factor reduction and
amplitude pre-distortion circuit is the envelop of the amplifier output.
The Crest Factor reduction and amplitude pre-distortion could be
performed in digital or analog domain.