Digital filter having a substantially equal number of negative and positive weighting factors
AssigneeU.S. Philips Corporation
InventorsMarcellinus J. M. Pelgrom, Stefan E. J. Menten
Life of this patent
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Abstract
In a digital filter in which coefficients are realised using power of two weighting factors, it can occur that due to rounding errors the output signal shows some inaccuracies. By decomposing the filter coefficients into powers of two in such a way that most powers of two have a counterpart with an opposite sign, the rounding errors tend to cancel, resulting in a more accurate filter.
Claims9
Digital filter comprising means for determining a combination of delayed sample values weighted with filter coefficients, said filter coefficients being decomposed into weighting factors being proportional to a power of two, characterized in that the number of weighting factors with a predetermined power of two and having opposite signs is substantially equal.
Digital filter comprising means for determining a combination of sample values weighted with filter coefficients, said filter coefficients being decomposed into weighting factors being proportional to a power of two, characterized in that the number of weighting factors with a predetermined power of two and having opposite signs is substantially equal.
Dependencies are inferred from the claim text.