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. 03, 1980
Filed:
Apr. 09, 1979
Yau-Chau Ching, Morganville, NJ (US);
Ben-Zion Gotz, Holmdel, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Known adaptive differential pulse code modulation (ADPCM) coders typically convert a nonuniform input signal to a linearized representation thereof prior to processing the signal. Usually the linearized signal requires more bits than the nonuniform signal. To mitigate the expense of apparatus for manipulating signals having many bits as well as to dissipate a scale size mistrack between the coder and a decoder, the instant ADPCM coder, responsive to an improved adaptive control signal, converts (300, 600) the nonuniform input signal to special semiuniform representation thereof which representation is processed (400, 500, 600) by the ADPCM coder. The semiuniform signal permits use of fewer bits than the prior art linearized representation. Also, the adaptive control signal is provided by a scale index generator including rounding-up and rounding-down means, for dissipating scale size mistrack. Further, the semiuniform signal permits much of the ADPCM process to be confined to relatively inexpensive read only memory (ROM) devices (300, 400, 500, 800).