Patent 7251301 was granted and assigned to Industrial Technology Research Institute on July, 2007 by the United States Patent and Trademark Office.
Providing a noise signal comprises providing a first signal corresponding to a first band of a frequency spectrum of the noise signal and providing a first signal low corresponding to the first band of the freguency spectrum of the noise signal. Next, providing a noise signal comprises providing a second signal corresponding to a second band of the frequency spectrum of the noise signal, the second signal based on the first signal low. And finally, the first signal and the second signal are summed to provide the noise signal.