Adaptive differential pcm coding
CA 1215177 A · Owner: Western Electric Company, Incorporated · Inventors: Petr, David W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, An ADPCM coder converts a linear PCM input signal representative of PCM encoded speech or voice band data into a quantized n-bit differential PCM output signal. Samples of the PCM input signal are delivered to a difference circuit along with a signal estimate of the same derived from an adaptive predictor. The resultant difference signal is coupled to the input of a dynamic locking quantizer. A quantized version of the difference signal is delivered from the output of said quantizer to an algebraic adder where it is algebraically added with the signal estimate. The result of this addition is coupled to the input of the adaptive predictor, which in response thereto serves to …
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
- Granted December 9, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 9, 2003.
- 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.