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:
Aug. 22, 1989
Filed:
Sep. 21, 1987
Zeev Shpiro, Tel Aviv, IL;
ECI Telecom Ltd., Tel Aviv, IL;
Abstract
Apparatus and technique for ADPCM transmission of voiceband data at rates up to and including 9600 bits/s via an ADPCM system comprising an ADPCM transmitter receiving PCM encoded signals at an 8 KHz sampling rate and being operative to transmit data at a sampling rate of 6.4 KHz and a transmission rate of 5 bits per sample and an ADPCM receiver having apparatus for receiving the transmitted data from the ADPCM transmitter and being operative for providing PCM encoded signals at an 8 KHz sampling rate. The ADPCM transmitter includes an adaptive quantizer which is operative to provide an output signal I(n), employing a scale factor adapted according to a discrete function difference signal W(I) having a relationship to I(n) which typically is substantially different from that given in recommendation G.721 of the CCITT. The ADPCM transmitter also includes an adaptive predictor having predictor coefficients which are updated using a leak factor lower than that shown in recommendation G.721 of the CCITT.