Echo cancellation system and method with reduced residual echo
US9947337B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 2017 |
| Grant date | Apr 17, 2018 |
| Priority date | — |
| Expiry date | Mar 21, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2430/03
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An echo canceller includes a fast Fourier transform (FFT) unit to provide frequency domain representation (FD) of an input. A multiband adaptive filter receives the FD of the input and provides an FD filter output, the adaptive filter is a finite input response (FIR) digital filter. Another FFT unit provides an FD of a microphone signal, and a summer adds the FD filter output to the FD of the microphone signal to provide echo-canceller FD output. A feedback subsystem uses the echo-canceller FD output to adjust filter coefficients of at least a first, a second, and a third frequency band of the multiband adaptive filter to minimize uncancelled output in the echo-canceller FD output. The feedback subsystem adjusts the filter coefficients of the second frequency band of the adaptive filter according to uncancelled output in the first, second, and third frequency bands of the echo-canceller FD output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.