Common control digital echo suppressor
US4029912A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1975 |
| Grant date | Jun 14, 1977 |
| Priority date | — |
| Expiry date | Dec 10, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/20
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A common control digital echo suppressor is disclosed which is configurable as full or split selectively on a channel-by-channel basis. Improved break-in and reduced hangover are provided by an arrangement for approximating the anticipated echo signals more accurately and by a wait-window technique to better distinguish between impulse noise and speech for break-in. The echo signal arrangement accurately approximates anticipated echo during both the rising and falling portions of speech signals. The wait-window technique provides for substantially instantaneous break-in, then a short wait period for impulse noise to subside, followed by a speech sampling window. If outgoing signals are detected during the window, suppression removal goes into a full break-in state. Otherwise, suppression is reinserted at the end of the window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.