Method of capturing constant echo path information in a full duplex speakerphone using default coefficients
US7187765B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2003 |
| Grant date | Mar 6, 2007 |
| Priority date | — |
| Expiry date | Apr 28, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method of determining when to save default coefficients in an echo canceller so as to ensure that the capture of coefficients that correspond to the best possible echo cancellation in a current condition. Coefficients are saved at varying times depending on the amount of echo removed by the echo canceller. More particularly, the present method involves constantly monitoring the error signal to the echo canceller and comparing it with the error signal that would be obtained if default coefficients were to be used instead of the current coefficients. This ensures that the default coefficients are upgraded each time the current set of coefficients is better than the saved default coefficients.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.