Path change detector for echo cancellation
US7555117B2 · kind B2 · utility
4Cited by
16References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2005 |
| Grant date | Jun 30, 2009 |
| Priority date | — |
| Expiry date | Jul 31, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A path change is detected by multiplying the energy of a signal on the output of a summation circuit in one channel of a telephone by a constant to produce a product. The product is compared with the energy of a signal on the input of the summation circuit. A path change is indicated when the energy of the product exceeds the energy of a signal on the input of the summation circuit. The comparison is made in successive frames of an audio signal and a path change is indicated when the energy of a signal on the input of the summation circuit is exceeded in two or more successive frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.