Transceiver system with analog and digital signal echo cancellation having adaptably adjustable filter characteristics
US7756228B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 2006 |
| Grant date | Jul 13, 2010 |
| Priority date | — |
| Expiry date | Feb 18, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03254
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Analog echo-cancelling circuitry (611 and 627) operates on an input analog signal that includes an echo of an output signal, or on an analog signal generated from the input signal, to produce an analog signal with reduced echo. An analog-to-digital converter (210) converts the echo-reduced analog signal, or an analog signal generated therefrom, into a digital signal. Digital echo-cancelling circuitry (615 and 621) operates on the digital signal, or on a digital signal generated therefrom, to produce a digital signal with further reduced echo. An output decoder (605) decodes the echo-reduced digital signal, or a digital signal generated therefrom, into a stream of symbols. The echo-filtering characteristics of both echo-cancelling circuitries are typically adaptively adjusted during generation of the symbol stream. The analog echo-filtering characteristics may be adapted in response to information provided by operating on the echo-reduced digital signal or on a digital signal generated therefrom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.