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. 12, 2012
Filed:
Aug. 06, 2009
Masashi Takada, Yokohama, JP;
Masashi Takada, Yokohama, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
An echo canceler uses an adaptive filter to remove an echo of a far-end input signal from a near-end input signal. Filter coefficients are calculated and updated while the far-end signal is active. While the far-end signal is silent, substitute filter coefficients are similarly calculated to be swapped in as initial values for the filter coefficients when the far-end signal changes from silent to active. The substitute filter coefficients are generated from a simulated far-end signal and a simulated near-end signal obtained by combining corresponding samples in different intervals of the far-end and near-end input signals. To facilitate convergence of the substitute filter coefficients, use of the simulated far-end and near-end signals is disabled when the corresponding samples cancel out.