Multi-channel echo canceler and method using convolution of two training signals
US5896452A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1996 |
| Grant date | Apr 20, 1999 |
| Priority date | — |
| Expiry date | May 24, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/238
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A two-wire line and a four-wire line telephone system interface with each other through a hybrid (12). After a connection between the two and four-wire line systems is made, an echo canceler (10) provides training signals to the hybrid on the transmit path an generates echo cancellation signals on the receive path. An adaptive filter (16) is employed to provide the proper echo cancellation signals, while a controller (22) provides filter coefficients based on an error signal. The training signals include the convolution of an impulse function with a sin(x)/x function. Once the filter coefficients are determined for the particular call, the transmit path of the four-wire line system is switched in and voice data between the two systems my commence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.