Multistage echo canceler including time variation compensation
US5610909A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 31, 1995 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | May 31, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Acoustic echos are canceled by employing a first echo canceler having a comparatively long first impulse response synthesis capability which is connected between a transmit path and receive path for generating a first error signal and for canceling echo signals in the transmit path, and at least a second echo canceler having a comparatively short second impulse response synthesis capability connected in parallel with the first echo canceler between the transmit and the receive path. The second echo canceler is supplied with the first error signal from the first echo canceler and is adaptively operating simultaneously with but independent of the first echo canceler to further cancel echos in the transmit path. Specifically, the first echo canceler is intended to capture the substantially stationary and any slowly varying components of the echo path impulse response, and the second echo canceler is intended to capture the more time varying, i.e., dynamically varying, component of the echo path impulse response.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.