Channel control and post filter for acoustic echo cancellation
US7177416B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 2002 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Oct 27, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An acoustic echo canceller comprising an adaptive filter, a post filter, and an adjustable filter. The adaptive filter receives a reference signal and a near-end signal, cancels a portion of the echo in the near-end signal using the reference signal, and provides an intermediate signal having remaining echo not canceled by the adaptive filter. The post filter calculates the cross-correlation between the near-end signal and intermediate signal, and provides a set of coefficients based on a variable suppression parameter. The adjustable filter processes the intermediate signal based on the coefficients and provides an output signal having at least a portion of the remaining echo removed. The acoustic echo canceller may further comprise a channel control unit that provides control signals, an adjustable amplifier, a noise estimator that estimates the noise in the intermediate signal, and a noise reinsertion unit that reinserts a version of the estimated noise back into the output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.