A multi-channel transmission system and method provide peak power smoothing without additional in-band interference. The system includes a multi-carrier waveform generator for reducing peak amplifier power required to transmit a digital multi-carrier waveform based on a plurality of digital carrier waveforms. A signal conversion system generates an analog multi-carrier waveform based on the digital multi-carrier waveform. The analog multi-carrier waveform has a center frequency and a desired gain over the original signal. A bandpass filter is coupled to the signal conversion system for restriction of the analog multi-carrier output waveform to a desired transmission bandwidth. The multi-carrier waveform generator has a nulling waveform generator coupled to a plurality of single carrier waveform modules for generating a digital nulling waveform based on the retrieved data. The nulling waveform reduces a peak power of the multi-carrier waveform and results in a reduced signal envelope.