Representation of PWM signals through time warping

In this work a novel approach for representing pulse width modulated (PWM) signals is introduced. PWM signals are usually represented according to the way they are generated, that is, by manipulating the sign of the comparison between the input signal and a reference wave. On the contrary, the new representation consists of a warped Fourier series, that is, a series of properly phase-modulated sinusoids, such that the zero-crossings of each warped harmonic comprehends the zero-crossing of the PWM signal. Yet, in contrast with the original signal, the spectrum of the resulting components decays exponentially, so they can be sampled at reasonable low rate while maintaining aliasing negligible. Being band-limited and keeping zero-crossings unaltered, this representation is suitable for computationally efficient PWM signal generation. © 2012 IEEE.