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:
Feb. 24, 1987
Filed:
May. 09, 1984
Applicant:
Inventors:
Otakar A Horna, Bethesda, MD (US);
Edwin A Stennett, Gaithersburg, MD (US);
Ferial T El-Mokadem, Great Falls, VA (US);
Assignee:
Communications Satellite Corporation, Washington, DC (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
379406 ;
Abstract
An echo canceller comprising an adaptive finite impulse response filter receiving a receive signal and having its output subtracted from a send signal, a non-linear device for attenuating low level signals of the send signal and a noise injector for injecting noise into the send signal proportional to a dynamically measured background noise in the subtracted output. The non-linear device and the noise injector are disabled when the receive signal is below expected noise level or the send signal is at a high level relative to the receive signal.