Apparatus and method for adapting an echo canceller in a communication system
CA 2279360 C · Owner: Motorola, Inc. · Inventors: Liu, Hanyu; Tan, Lijun
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An apparatus and method for adapting an echo canceller in a communication system reduces the number of taps in the echo canceller filter in order to reduce the amount of processing resources consumed by the echo canceller. A near-end echo canceller (406) is disabled if the modem (402) operates on the digital side of a digital-to-analog connection. A far-end echo canceller (408) is disabled if the modem (402) operates on the analog side of a digital-toanalog connection or if the round-trip delay is below a predetermined threshold. The far-end echo canceller (408) is truncated if the span of the far-end echo canceller overlaps the span of the near-end echo canceller (406).
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed November 13, 1998 and granted October 22, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 13, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 13, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.