Method for detecting echo path changes in echo cancellers
US7508931B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 2005 |
| Grant date | Mar 24, 2009 |
| Priority date | — |
| Expiry date | May 15, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/234
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method for detecting echo path changes in an echo canceller using the statistics of the echo canceling behavior (i.e. signal and performance information), to distinguish between new line and double talk conditions. A moving counter is incremented or decremented based on monitored levels of ERL (Echo Return Loss), ERLE (Echo Return Loss Enhancement), noise and signal energies. When the counter reaches a predetermined threshold value indicative of sustained poor echo cancellation performance, a determination is made that there is a probable new line condition (i.e. echo path change). This echo path change information is then passed to the echo canceller to enable re-convergence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.