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:
Jun. 17, 2003
Filed:
Aug. 31, 1999
James Patrick Dunn, Township of Northville, LaSalle County, IL (US);
Peng Zhang, Buffalo Grove, IL (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
An echo canceling system with self deactivation includes an echo canceller based on an adaptive filter, and an echo detector. The adaptive filter determines an estimate of an echo signal present in an untreated signal received from a “near” end of a communications channel. In order to produce an echo-canceled received signal, the echo canceller subtracts the estimated echo from the untreated received signal. The echo detector compares the energy of the untreated received signal and the energy of the echo-canceled received signal. The difference represents the energy in the estimated echo signal generated by the adaptive filter. If this energy is large, significant echo is present. The echo canceller remains activated, and the echo detector selects the echo-canceled received signal for output. If the estimated echo energy is small, little or no cancelable echo is present. The echo canceller is deactivated, and the echo detector selects the untreated received signal for output. Where plural channels of echo cancellation are provided, the deactivated echo canceller may be reallocated to service another communications channel.