DSL transmission system with means for ensuring local echo orthogonality
US7103015B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 2, 2000 |
| Grant date | Sep 5, 2006 |
| Priority date | — |
| Expiry date | Mar 2, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2647
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A digital subscriber line transmission system comprising an IFFT circuit generating successive outgoing time domain symbols on a subscriber line from respective groups of digital frequency domain coefficients; an FFT circuit generating groups of digital frequency domain coefficients from respective incoming time domain symbols received on the subscriber line, a current incoming symbol being delayed with respect to a current outgoing symbol by a predetermined time interval; and circuitry for, during an end portion of a current incoming symbol, subtracting from the signal received on the subscriber line an estimated echo obtained by a filter from a signal portion following the end of the current outgoing symbol, and adding thereto, through said filter, a beginning portion of the current outgoing symbol, wherein said portions have a duration at least equal to said predetermined time interval.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.