Speech coding and decoding methods using adaptive and random code books
US5396576A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1992 |
| Grant date | Mar 7, 1995 |
| Priority date | — |
| Expiry date | May 20, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L2019/0011
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An excitation vector of the previous frame stored in an adaptive codebook is cut out with a selected pitch period. The excitation vector thus cut out is repeated until one frame is formed, by which a periodic component codevector is generated. An optimum pitch period is searched for so that distortion of a reconstructed speech obtained by exciting a linear predictive synthesis filter with the periodic component codevector is minimized. Thereafter, a random codevector selected from a random codebook is cut out with the optimum pitch period and is repeated until one frame is formed, by which a repetitious random codevector is generated. The random codebook is searched for a random codevector which minimizes the distortion of the reconstructed speech which is provided by exciting the synthesis filter with the repetitious random codevector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.