Adaptive transform coder having long term predictor
US5012517A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1989 |
| Grant date | Apr 30, 1991 |
| Priority date | — |
| Expiry date | Apr 18, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/90
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for removing the periodicity from a speech signal in a transform coder prior to the quantization of the speech signal, which speech signal is a sampled time domain speech signal composed of information samples, the transform coder sequenctially segregating the speech signal into blocks of information samples, is shown to include apparatus and method for determining the pitch in each of the sample blocks, determininig a long term predetermined parameter (LTP) for each of the blocks based on the pitch determined for each block, calculating a periodicity value for each sample in the block wherein the calculation of the periodicity value is based upon the pitch and the long term predictor parameter, generating a revised block of difference samples by subtracting the periodically value from the corresponding sample, and performing adaptive transform coding on each of the difference blocks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.