Dynamic codebook for efficient speech coding based on algebraic codes
CA 2010830 C · Owner: Universite De Sherbrooke · Inventors: Laflamme, Claude; Adoul, Jean-Pierre
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of encoding a speech signal is disclosed. This method improves the excitation codebook and search procedure of the conventional Code Excited Linear Prediction (CELP) speech encoders. Use is made of a dynamic codebook based on a combination of two modules: a sparse algebraic code generator associated to a filter having a transfer function varying in time. The generator is a structured codebook with codewords having very few non zero components. The filter shapes the spectral characteristics whereby the resulting excitation codebook exhibits favorable perceptual properties. The search complexity in finding the best codeword is greatly reduced by bringing the search back to the …
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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 February 23, 1990 and granted June 25, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 23, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 23, 2012.
- 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
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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.