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:
Oct. 12, 1982
Filed:
Jun. 09, 1980
Applicant:
Inventors:
Takashi Araseki, Tokyo, JP;
Kazunori Ozawa, Tokyo, JP;
Assignee:
Nippon Electric Company, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
375 27 ; 329107 ; 332 / ; 375 60 ;
Abstract
In an adaptive differential pulse code modulation (ADPCM) system for frequency band compression of speech or like signals, the coefficient of the synthesis filter in both the transmitter and receiver is varied in accordance with the normalized error e.sub.j /.DELTA. rather than the error itself, thus providing greater frequency band compression and preventing transmission errors from rendering the synthesis filter unstable.