Speech bandwidth extension method and apparatus
US5455888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1992 |
| Grant date | Oct 3, 1995 |
| Priority date | — |
| Expiry date | Dec 4, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L2019/0012
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A speech bandwidth extension method and apparatus analyzes narrowband speech sampled at 8 kHz using LPC analysis to determine its spectral shape and inverse filtering to extract its excitation signal. The excitation signal is interpolated to a sampling rate of 16 kHz and analyzed for pitch control and power level. A white noise generated wideband signal is then filtered to provide a synthesized wideband excitation signal. The narrowband shape is determined and compared to templates in respective vector quantizer codebooks, to select respective highband shape and gain. The synthesized wideband excitation signal is then filtered to provide a highband signal which is, in turn, added to the narrowband signal, interpolated to the 16 kHz sample rate, to produce an artificial wideband signal. The apparatus may be implemented on a digital signal processor chip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.