A system and method for waveform modulation includes encoding input digital data at selected phase angles of an unmodulated sinusoidal waveform. The encoding includes selectively reducing a power of the unmodulated sinusoidal waveform at the selected phase angles in accordance with bit values of the input digital data so as to respectively define first, second, third and fourth data notches in the modulated sinusoidal waveform. An encoded analog waveform is then generated from a digital representation of the modulated sinusoidal waveform. The encoding is performed so that energies associated with the first and third data notches are balanced and energies associated with second and fourth data notches are also balanced. Each of the energies corresponds to a cumulative power difference between a power of the unmodulated sinusoidal waveform and a power of the modulated sinusoidal waveform over a phase angle range subtended by one of the data notches.