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Expired Canadian patentCanada

Error tracking loop

CA 2131998 C · Owner: Lee, Ronald B. · Inventors: Krishnamurthy, Gopalan; Lee, Ronald B.; Horwitz, Thomas P.

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Abstract From the Canadian patent

A circuit for correcting errors in a received complex data signal including a synchronous detector for recovering an in-phase data component from the received signal and a Hilbert transform filter for estimating the related quadrature component from the recovered in-phase data component, the recovered in-phase data component including a periodically recurring reference signal. A decision feedback loop is periodically operable in response to the reference signal for initially error correcting a selected characteristic of the received signal at a first relatively rapid rate and for subsequently error correcting the selected characteristic at a rate which is less than the first rate and which …

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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 January 11, 1994 and granted March 14, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 11, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 11, 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.
FiledJanuary 11, 1994
GrantedMarch 14, 2000
Term endedJanuary 11, 2014
Patent numberCA 2131998 C
Classification (IPC)H04L1/00 +1 more

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedJan 11, 1994Patent grantedMarch 14, 2000Term endedJan 11, 2014

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.