Low delay modulated filter bank
US8880572B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 2010 |
| Grant date | Nov 4, 2014 |
| Priority date | — |
| Expiry date | Apr 23, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2017/0297
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The document relates to modulated sub-sampled digital filter banks, as well as to methods and systems for the design of such filter banks. In particular, the present document proposes a method and apparatus for the improvement of low delay modulated digital filter banks. The method employs modulation of an asymmetric low-pass prototype filter and a new method for optimizing the coefficients of this filter. Further, a specific design for a (64) channel filter bank using a prototype filter length of (640) coefficients and a system delay of (319) samples is given. The method substantially reduces artifacts due to aliasing emerging from independent modifications of subband signals, for example when using a filter bank as a spectral equalizer. The method is preferably implemented in software, running on a standard PC or a digital signal processor (DSP), but can also be hardcoded on a custom chip. The method offers improvements for various types of digital equalizers, adaptive filters, multiband companders and spectral envelope adjusting filterbanks used in high frequency reconstruction (HFR) or parametric stereo systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.