Pulse width modulator
AssigneeHarman Becker Automotive Systems GmbH
InventorGerhard Pfaffinger
Life of this patent
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Abstract
A pulse width modulator for modulating a rectangular carrier signal in accordance with an input signal includes a modulating unit that receives the input signal and provides a digital output word. The output word has a pre-defined number of digits comprising a first contiguous set of binary ones (“1”) and a second contiguous set of binary zeroes (“0”) and in which the fraction of the binary ones (“1”) represents the digital input signal. The modulator also includes a random number generator that generates a pseudo-random sequence, and a flipping unit configured to flip, or not, the output word provided by the modulating unit in accordance with the pseudo-random sequence thus providing a randomly modified digital pulse width modulated output signal.
Claims10
A pulse width modulator for modulating a rectangular carrier signal in accordance with an input signal s[n], the modulator comprises:
- a modulating unit that receives the input signal s[n] and generates a digital output word, the output word having a pre-defined number of digits (2b) comprising a first contiguous set of “1” and a second contiguous set of “0” digits in which the fraction of “1” digits represents the digital input signal s[n];
- a random number generator that generates a random sequence a[n];
- and
- a flipping unit that receives the random sequence a[n] and the output word and selectively flips, or not, the output word provided by in accordance with the pseudo-random sequence a[n] to provide a randomly modified digital pulse width modulated output signal.
Dependencies are inferred from the claim text.