The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 23, 1992
Filed:
Feb. 08, 1991
Alain Charbonnier, Versailles, FR;
Jean P Petit, Minihy-Treguier, FR;
France Telecom, Paris, FR;
Abstract
A quantization device with variable digital coding rate for coding and decoding sound and speech in telecommunications and frequency transform coding. For a signal of amplitude .vertline.x.vertline. whose probability density is of the Laplace law type p(x)=.alpha./2e.sup.-.vertline.x.vertline., this device comprises a quantizer operator and a reverse quantizer operator. The quantizer operator includes an operator for calculating the ampltiude signal and a sign signal, an operator for combining the amplitude signal .vertline.x.vertline. and the number N of digital codes by subtracting a term KN=3/.alpha. Log (N+1) and a quantizer with fixed quantization thresholds in which the value of the thresholds Li is determined by the relation Li=-3/.alpha. Log (i+1). The reverse quantizer operator includes a reverse quantizer with fixed reverse quantization levels i with i=3/.alpha. Log (2i+2), an operator for combining a normed decoded amplitude signal and the number N of digital codes by addition of said term KN for delivering a decoded ampltiude signal .vertline.y.vertline. and an operator for combining the decoded amplitude signal .vertline.y.vertline. and the sign signal IS for delivering a reconstituted digital signal corresponding to the digital signal x.