Speech coding system and method including spectral quantizer
US6094629A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1998 |
| Grant date | Jul 25, 2000 |
| Priority date | — |
| Expiry date | Jul 13, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/07
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A speech coding system and associated method relies on a speech encoder and a speech decoder. The encoder includes a spectral quantizer for computing line spectral frequencies (LSFs) for respective frames of speech and for quantizing the LSFs to obtain a minimum bit representation of a spectral envelope of each respective frame of speech. For even numbered frames of speech the LSFs are quantized using a vector quantization technique. For odd numbered frames of speech samples the LSFs are quantized using a dynamic bit allocation (DBA) method. The dynamic bit allocation method determines an interpolation factor for interpolating between the LSFs of the previous and next frames. According to the dynamic bit allocation method the most perceptually important LSFs are represented by relatively more bits, while the least perceptually important LSFs are represented by relatively fewer bits. The system and associated method thereby reduces an overall bit rate required to represent, transmit or store the speech samples.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.