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:
Dec. 12, 1995
Filed:
Jan. 07, 1994
Jim A Rasmusson, Brosarp, SE;
Ericsson Inc., Research Triangle Park, NC (US);
Abstract
An echo-canceling system and method uses an echo estimate to modify the error signal which is obtained by the difference between an echo signal and the echo estimate. The modified error signal, rather than the error signal itself, is transmitted. By using the echo estimate as a parameter for modifying the error signal, improved hands-free performance may be obtained in a vehicular radiotelephone, such as a cellular telephone. Preferably, modification of the electrical error signal is performed by a center clipper which removes a portion of the electrical error signal which is below a variable threshold, wherein the variable threshold is determined by the echo estimate electrical signal. The variable threshold may be produced from the echo estimate electrical signal using an envelope detector.