Method and device for protecting modems against echoes
US4823339A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1987 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | May 29, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The device for providing protection against echoes includes a level memory (33) for storing a value Gs and a comparator (34) for comparing the level Gx provided by an AGC device (31) upon receipt of a message with a value Gs stored in the level memory (33) and for supplying a resetting signal to the equalizer (35) for resetting the coefficients thereof to zero together with a signal for storing the level Gx as a new value Gs in the level memory (33) where Gx exceeds Gs by a predetermined value, or for supplying a signal for inhibiting the decoding of the data signals where Gx falls short of Gs by a predetermined value, thereby indicating that the received message is an echo.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.