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. 22, 1986
Filed:
Jul. 23, 1982
John F O'Neill, Boulder, CO (US);
GTE Lenkurt Incorporated, San Carlos, CA (US);
Abstract
An improved adaptive echo cancelling system and method is disclosed. The system and method utilizes linear code spacing and is particularly well suited for echo cancellation of full scale signals. Echo cancellation is effected by use of digital-to-analog converters functioning as a multiplier receiving first digital signals representative of a received speech waveform signal and second digital signals representative of the termination network on the line, which termination network causes and defines an echo reflection of the received signal. The output of the multiplier is summed and the sum is then subtracted from the echo components of the received signal to thus achieve echo cancellation and to produce an error signal that is utilized to continuously reduce error between the actual and estimated echo waveforms. Provision is made to inhibit error indications due to circuit generated coding noise and/or predetermined small detected errors to thereby enhance system operation.