An example apparatus includes: crest factor reduction circuitry having a signal input and a peak cancellation waveform input; and peak cancellation waveform generator circuitry including: carrier profile analyzer circuitry having a signal input coupled to the signal input of the crest factor reduction circuitry, and having a carrier profile output; waveform construction circuitry having a carrier profile input coupled to the carrier profile output of the carrier profile analyzer circuitry, having a second input, and having a peak cancellation waveform output coupled to the peak cancellation waveform input of the crest factor reduction circuitry; and profile change detector circuitry having a carrier profile input coupled to the carrier profile output of the carrier profile analyzer circuitry, and having an output coupled to the second input of the waveform construction circuitry.