A variable block size adaptation algorithm for noise-robust acoustic echo cancellation
CA 2174342 C · Owner: Sih, Gilbert C. · Inventors: Sih, Gilbert C.; Antonio, Franklin P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An apparatus that automatically adjusts the adaptation block size for a least-mean square (LMS) adaptive filter depending on the input signal-to-noise ratio (SNR) is disclosed. The apparatus monitors the instantaneous SNR (22) and continually adjusts the block size (20,26) to provide high noise immunity thereby increasing the convergence speed of the filter and decreasing the asymptomatic mean-square error. An exemplary embodiment of the present invention is presented in the context of acoustic echo cancellation though it is noted that the adaptive filter of the present invention is useful in any environment in which the noise characteristics are subject to change.
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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 October 27, 1994 and granted December 14, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 27, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 27, 2016.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.