Method and apparatus for canceling echo accounting for delay variations
US5675644A · kind A · utility
21Cited by
44References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 26, 1995 |
| Grant date | Oct 7, 1997 |
| Priority date | — |
| Expiry date | Sep 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/23
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting and correcting for variations in the flat delay, which permits smooth echo canceller operation even under dynamic delay conditions. In a delay monitor, the received signal is compared against delayed versions of the echo estimate to determine whether a shift in the echo delay has occurred. If such a shift in delay has occurred then a signal indicating the amount of the shift is to the adaptive filter of the echo canceller and the filter taps are updated in accordance with the delay shift value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.