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. 07, 1984
Filed:
Feb. 08, 1982
Jean-Paul Beraud, Saint Laurent du Var, FR;
Claude Galand, Cagnes sur Mer, FR;
International Business Machines Corporation, Armonk, NY (US);
Abstract
An improved split-band coder reduces signal-processing time, thereby reducing echo delay time and listener confusion. The voice-originated signal to be transmitted over a transmission line is sampled and digitally coded at a relatively high bit rate; the spectrum of said signal is then partitioned into p sub-bands. The sample stream of the signal so-filtered and partitioned into p sub-bands is split into blocks of samples, or portions, of a given time duration. A requantizing device proceeds for each block to the requantizing of the samples in each sub-band by means of requantizing parameters derived from the samples of the preceding sample block, whereas new requantizing parameters are determined and stored with a view to requantizing the following sample block. The requantized samples in the different sub-bands are multiplexed, and transmitted over the transmission line, together with the values of the highest amplitude samples in each sub-band.