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:
Nov. 23, 1982
Filed:
Sep. 05, 1979
Otakar A Horna, Bethesda, MD (US);
Communications Satellite Corporation, Washington, DC (US);
Abstract
Three double talk detectors (DTD) are used in combination with an echo canceller having an adaptive filter and a center clipper. First and second double talk detectors are used in the presence of double talk to selectively freeze the adaptive filter correction loop and to disable the center clipper. The third double talk detector is used to detect the initial adaptive period of the echo canceller. Control of the adaptive filter and clipper is effectively transferred from the first to the second double talk detector upon termination of the initial adaptive period as determined by the third double talk detector. The third double talk detector also detects a false double talk condition (where the distant talker pauses in speech) and overrides the second double talk detector in order to maintain the clipper in an active state.