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:
May. 02, 2006
Filed:
May. 28, 1999
Alexandre L. Leonidov, Skokie, IL (US);
Vladimir G. Parizhsky, New York, NY (US);
Alexandre L. Leonidov, Skokie, IL (US);
Vladimir G. Parizhsky, New York, NY (US);
3Com Corporation, Marlborough, MA (US);
Abstract
Methods and systems pertaining to preventing the corruption of filter coefficients due to near end speech in an echo canceller that uses an adaptive filter to create a local replica of an echo signal are provided. In accordance with a preferred method, a far end signal is received and the presence of near end speech is indicated. A filter coefficient vector is updated, and copies of the filter coefficient vector are periodically stored. A stored copy of the filter coefficient vector is recovered for use in the echo canceller. Further, an improved echo canceller that prevents the corruption of filter coefficients due to near end speech, having a near end speech indicator, a first buffer, a filter, and a second buffer connected to the filter, is provided. The first buffer receives a far end signal. The filter is responsive to the first buffer and the near end speech indicator. The filter includes a filter coefficient vector generator, wherein the generator generates, updates, and provides copies of filter coefficient vectors. The second buffer is connected to the filter and stores the copies of the filter coefficient vectors for restoration to the filter.