Speech coding method using linear prediction and algebraic code excitation
CA 2182386 C · Owner: France Telecom · Inventors: Lamblin, Claude
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method using the algebraic index CELP coding technique. The search for CELP excitation comprises calculating certain components of covariance matrix U = H<T>.H where H is a lower triangular Toeplitz matrix formed from the impulse response of a filter consisting of synthesis filters and a perceptual weighting filter. The stored covariance matrix components are only those of pattern U(posi,p,posi,p) and those of pattern U(posi,p,posj,q) where posi,p and posj,q are the i position and the j position respectively for pulses p and q in the algebraic index codes.
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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 4, 1996 and granted September 9, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 4, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 4, 2018.
- 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.