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:
Jan. 27, 2004
Filed:
Nov. 12, 1999
Peter R. Molnar, Austin, TX (US);
Takao Inoue, Austin, TX (US);
Matthew A. Pendleton, Cedar Park, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
An echo canceler ( ) includes a summing device ( ) that subtracts a correction signal from a received signal, the difference of which represents the far-end signal with an error component. Instead of adapting its coefficients using the output of the summing device ( ), the echo canceler ( ) uses the difference between the input and output of a decision device ( ) as an estimate of the error component alone. The estimate of the error component is then used to adapt the coefficients according to the adaptive least mean squares (LMS) algorithm. In one embodiment, the decision device ( ) forms discrete multi-tone symbols based on the equalized output of the summing device. In this embodiment, the echo canceler ( ) performs an inverse of the equalization step efficiently by replacing a division operation with a multiply operation and a corresponding power-of-two shift operation.