Fast pitch tracking process for LTP-based speech coders
US5093863A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1990 |
| Grant date | Mar 3, 1992 |
| Priority date | — |
| Expiry date | Apr 6, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/09
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A process for deriving voice pitch related delay values M to tune a Long-Term Prediction (LTP) filter to be used in an LTP based speech coder converting a speech derived digital signal r(n) into a lower bit rate signal, said filter being provided with a variable length delay line y(n) fed with a reconstructed signal r'(n). The process includes splitting r(n) into segments and each segment into sub-segments; then cross-correlating the first current r(n) sub-segment with a previously reconstructed segment and sorting the cross-correlation values for peak location, whereby a first delay value M1 is derived and used to tune the filter. Then, said M1 is used to compute sample indexes n for a predefined number of samples located about M1/p, . . . , M1, 2M1, . . . , pM1 and repeating cross-correlation and sorting operations to derive M2 and so on up to a full segment length (e.g. 160 samples). Then the process is started all over again.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.