Method for testing echo cancellers
US8295501B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2008 |
| Grant date | Oct 23, 2012 |
| Priority date | — |
| Expiry date | Apr 30, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/493
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The performance of an echo canceller is assessed using a) a test signal launched from originating test equipment and b) a simulated echo of the test signal launched from terminating test equipment. The launch of the simulated echo signal is timed in such a way that it arrives at the tandem echo canceller(s) at a particular point in time relative to the arrival of the test signal, at the tandem echo canceller(s), when the tandem echo canceller(s) is (are) not able to cancel the simulated echo signal. The latter thus arrives uncanceled at the target echo canceller. The launch of the simulated echo signal is further timed in such a way that it arrives at the target echo canceller at a point in time relative to the arrival of the test signal, at the target echo canceller, when the target echo canceller is able to cancel the simulated echo signal. As a result, any residual echo received at the originating test equipment is a measure of the performance of the target echo canceller exclusive of the performance of the tandem echo canceller(s).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.