Code-excited linear predictive coder and decoder with conversion filter for converting stochastic and impulsive excitation signals
US5752223A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1995 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Nov 14, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L2019/0005
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A code-excited linear predictive coder or decoder for a speech signal has an adaptive codebook, a stochastic codebook, and a pulse codebook. A constant excitation signal is obtained by choosing between a stochastic excitation signal selected from the stochastic codebook and an impulsive excitation signal selected from the pulse codebook. The constant excitation signal is filtered to produce a varied excitation signal more closely resembling the original speech signal. The varied excitation signal is combined with an adaptive excitation signal selected from the adaptive codebook to produce a final excitation signal, which is filtered to generate a synthesized speech signal. The final excitation signal is also used to update the adaptive codebook.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.