Multi-rate digital voice coder apparatus
US4890327A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1987 |
| Grant date | Dec 26, 1989 |
| Priority date | — |
| Expiry date | Jun 3, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An analog to digital converter for a speech signal is implemented in modules to allow for changes in bit rate and changes in bit stream length according to requirements of the digital transmission system. A pre-emphasis circuit provides an array of pre-emphasized speech samples which are stored in memory. A linear predictive coder provides an array of reflection coefficients and an array of filter coefficients. A pulse processor receives the speech samples and filter coefficients and generates speech amplitude and location signals. These signals are multiplied to generate quantized speech samples. The quantized speech samples and reflection coefficients are provided to a buffer which provides an output signal of a proper bit stream length and bit rate for the digital transmission system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.