Method of capturing constant echo path information in a full duplex speakerphone
US7221755B2 · kind B2 · utility
0Cited by
6References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2002 |
| Grant date | May 22, 2007 |
| Priority date | — |
| Expiry date | Dec 18, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method of improving convergence of an echo canceller in a full duplex speakerphone, wherein the echo canceller includes LEC (Line Echo Canceller) and AEC (Acoustic Echo Canceller) portions, comprising the steps of capturing coefficients during operation, storing the coefficients, and utilizing the stored coefficients as default values during start-up of a subsequent call. According to the method of the present invention, the amount of echo cancellation necessary to provoke a save of the coefficients decreases with time when it is not achieved by the system despite the presence of a reference signal (i.e. speakerphone signal).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.