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:
Apr. 08, 1986
Filed:
Mar. 05, 1984
Dimitrios P Prezas, Park Ridge, IL (US);
Nancy M Saraf, Lisle, IL (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
Disclosed is a digital arrangement utilizing linear predictive coding for equalizing over a desired frequency spectrum the variable attenuation of a voice-frequency message signal transmitted on a communication line. The arrangement comprises a digital signal processor, program memories for storing program instruction sets, and a data memory for storing samples of a spectrally white test signal that has been variably attenuated by the line. Under control of one instruction set that incorporates linear predictive coding, the processor uses the stored test samples to calculate the reflection coefficients of the line that characterize the variable attenuation of a signal on the line. Under the control of the other instruction set, the processor functions as a digital inverse filter employing the calculated reflection coefficients for equalizing over the desired frequency spectrum the variable attenuation of a voice-frequency message signal transmitted on the line.