Acoustical echo canceller with sub-band filtering
US5889857A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1996 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Aug 28, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The echo canceller is designed to be placed between a hands-free acoustical interface and a communications network. It comprises a plurality of processing paths connected in parallel and each allocated to one of a plurality of adjacent sub-bands taken from the spectrum band of the output signal. Each path comprises an analysis filter receiving the echo-containing signal for transmission after correction, a second analysis filter receiving the incoming signal coming from the network, and feeding an adaptive filter that supplies an estimated echo in the respective sub-band to the subtractive input of the subtracter and a synthesis filter. The adaptive filters in at least some of the sub-bands implement a QR decomposition RLS algorithm on the incoming signal, using the fast version thereof, with or without recursive order.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.