Speech specific adaptive transform coder
US4991213A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1988 |
| Grant date | Feb 5, 1991 |
| Priority date | — |
| Expiry date | May 26, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/90
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A transform coder operates on a sampled speech signal transformed from the time domain to a frequency domain to develop pitch information in relation to a given speech signal. The coder segregates groups of information samples into blocks, transforms each block of samples, and generates an auto-correlation function of the transformed signal for each block. Next, the coder determines the pitch period and pitch gain from the auto-correlation function, and determines the striation magnitude and energy from the pitch period and pitch gain. Then a reference pitch model including a number of data points is retrieved from data memory. A striation scaling factor is generated in response to the striation magnitude and energy, and is multiplied by each of the retrieved data points to adaptively generate a pitch model. Finally, the adaptively determined model is sampled to establish the pitch information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.