Noise cancelling method and noise cancelling unit
CA 2273552 C · Owner: Nec Corporation · Inventors: Ikeda, Shigeji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A signal-to-noise power ratio estimation circuit 22 detects an error signal power of an error signal output from a subtracter 13 and a pseudo noise signal power of a pseudo signal output from an adaptive filter 12 and based on the detected signal powers, outputs an estimated value SNR1 of a signal-to-noise power ratio. An SNR average circuit 20 calculates an average value SNR4 of the SNR1. A step size output circuit 21 controls the step size of she adaptive filter 12 according to the SNR4 value.
Read the whole patent
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 June 2, 1999 and granted March 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 2, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 2, 2021.
- 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.