Digital voice transmission having improved echo suppression
US4652703A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 1983 |
| Grant date | Mar 24, 1987 |
| Priority date | — |
| Expiry date | Mar 1, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/20
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A digital voice communication apparatus having improved echo suppression includes a transmission gain detection circuit for detecting a near talker signal and a receiver gain detection circuit for detecting a far talker signal. An echo detecting circuit detects which of the near talker and far talker signals has a lesser value and suppresses the gain of the one detected to have the lesser value. A far talker suppressing circuit detects whether the most recent peak gain in this near talker signal is greater than a threshold and is greater than the gain of the far talker signal. If this condition exists the far talker signal is suppressed. A near talker signal suppressing circuit detects whether the most recent gain of the far talker signal is greater than a threshold and is greater than the gain of the near talker signal. If so, the gain of the near talker signal is suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.