Method and apparatus for pulse position modulation

Abstract

A method for reducing the transition rate of a pulse width modulated signal representing an original signal, and thus reducing energy losses of devices such as class D amplifiers stimulated by the signal, while decreasing the jitter and thus the SNR of the output low passed signal. Within the method every R pulses of a signal having a frame duration of M, are summed to receive frames of R*M duration having a single pulse. Then, the odd pulses are mirrored within their respective time frames, so that each odd pulse is attached to the following even pulse. The combined pulse, which occurs in a window having a duration of 2*R*M is then optionally re-positioned within its time frame. The repositioning can be designed so as to position the pulse within the 2*R*M window, having the same moment as the original signal, or to receive a signal having the same phase of the Fourier transform as the original signal, at least for the frequency range of interest of the original signal, such as the low frequencies. Other aspects, features, and embodiments are also claimed and described.

Dependencies are inferred from the claim text.