Methods and apparatus for distinguishing stationary signals from non-stationary signals
US5774847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1997 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Sep 18, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In methods and apparatus for distinguishing stationary signals from non-stationary signals, a set of Linear Predictive Coding (LPC) coefficients characterizing spectral properties of the signal for each of a plurality of successive time intervals, including a current time interval, is determined. The LPC coefficients are averaged over a plurality of successive time intervals preceding the current time interval, and a cross-correlation of the LPC coefficients for the current time interval with the averaged LPC coefficients is determined. The signal is declared to be stationary in the current time interval when the cross-correlation exceeds a threshold value, and is declared to be non-stationary in the current time interval when the cross-correlation is less than the threshold value. The methods and apparatus are particularly applicable to detection of transitions between an absence of speech state, characterized by a stationary signal, and a presence-of-speech state characterized by a non-stationary signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.