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:
Jul. 28, 1992
Filed:
Dec. 11, 1990
James D Johnston, Warren, NJ (US);
Scott C Knauer, Mountainside, NJ (US);
Kim N Matthews, Watchung, NJ (US);
Arun N Netravali, Westfield, NJ (US);
Eric D Petajan, Watchung, NJ (US);
Robert J Safranek, New Providence, NJ (US);
Peter H Westerink, Newark, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
In a differential PCM encoder, the problem of error perpetuation is solved by leaking a changing, rather than a fixed, fraction of the input signal to the differential PCM. The fraction leaked is sensitive to the characteristics of the signal. In one embodiment the fraction leaked is fixed for a frame in accordance with a chosen characteristic of the frame signal. In another embodiment, the fraction leaked is set in accordance with one function when a chosen characteristic of the frame signal exceeds a given level, and follows another function when the chosen characteristic does not exceed the chosen level. In a still another embodiment, the fraction leaked is set to one of two levels, based on a chosen characteristic of the frame signal.