Method for the adaptive filtering of a transformed signal in sub-bands and corresponding filtering method
US5327366A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 2, 1992 |
| Grant date | Jul 5, 1994 |
| Priority date | — |
| Expiry date | Sep 2, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/0266
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method of filtering in sub-bands that eliminates or greatly restricts aliasing effects is disclosed. First, a source digital signal is transformed into at least two distinct frequency sub-bands. Next, each of the frequency sub-bands is filter processed. The filter processing includes the steps of defining an overall filtering profile, determining a set of partial filtering profiles each associated with one of the sub-bands, and filtering each of the sub-bands according to the associated partial filtering profile. Finally, the filtered sub-bands are reverse transformed to deliver a reconstructed filtered signal. The determined partial filtering profiles are applied so that the reconstructed filtered signal corresponds substantially to a forward filtering of the source digital signal according to the overall filtering profile. In particular, the partial filtering profiles are applied such that the aliasing terms still present after filtering are substantially compensated for.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.