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:
Apr. 01, 2014
Filed:
Jun. 30, 2009
Nicholas P. Sands, Menlo Park, CA (US);
Kevin D. Fisher, Palo Alto, CA (US);
Nicholas P. Sands, Menlo Park, CA (US);
Kevin D. Fisher, Palo Alto, CA (US);
Ikanos Communications, Inc., Fremont, CA (US);
Abstract
A reduced-memory vectored DSL system includes methods and apparatus for reducing the bandwidth and memory storage demands on a vectored DSL system in which FEXT data is transmitted and stored. An upstream-end device such as a DSLAM communicates with a plurality of downstream-end devices such as CPE modems. When test signal data, such as training and/or tracking data, is sent to determine FEXT characteristics of the DSL system, error signals are available for all or substantially all of the upstream and/or downstream frequency band DSL tones used in the system. Dividing a frequency band into sub-bands, only a subset of tones in each sub-band is used for deriving FEXT data, such as a FEXT channel response, FEXT channel coefficients and/or FEXT cancellation coefficients. For tones in the sub-band subsets, full-precision FEXT data values can be derived. For other tones, approximations of the FEXT data can be derived.