Automatic gain control for an adaptive finite impulse response and method therefore
US7142665B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 2004 |
| Grant date | Nov 28, 2006 |
| Priority date | — |
| Expiry date | Oct 26, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus are provided for an echo cancellation system. The echo cancellation system comprises an automatic gain control (AGC), a first scalar, a second scalar, a signal summing stage, and an adaptive filter. The AGC is responsive to a first signal in a reference path and a second signal in a near end path. The signal summing stage is between the first and second scalar in the near end path and the first and second scalars are responsive to the AGC. The adaptive filter is responsive to the first signal and provides a third signal to the signal summing stage that corresponds to an echo signal and is subtracted from a signal in the near end path. The second scalar has a scale rate that is the inverse of the scale rate of the first scalar such that unity scaling occurs on the near end path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.