Method and apparatus for channel estimation for X-DSL communications
US6985521B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2001 |
| Grant date | Jan 10, 2006 |
| Priority date | — |
| Expiry date | Mar 18, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/487
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus and method is disclosed for channel estimation in an X-DSL communication device. The communication device may include physical or logical modems. The modems may implement one or more of a group of X-DSL protocols including: G.Lite, ADSL, VDSL, and HDSL. The apparatus may be used for determining the location and magnitude of discontinuities or faults within the communication medium to which the X-DSL communication device is coupled. The information provided by the device may be used for line qualification or repair. No additional equipment is required for channel estimation. Instead the apparatus may be located within a single modem or shared between a group of modems. An N bit pseudo random codeword injected into the transmit path is used to generate both a leakage signal and a plurality of reflected signals on the receive path. No timing information is needed from the transmit path. Instead a unique correlator is utilized on the receive path to extract timing information for the reflected signals relative to the leakage signal. The broad bandwidth of the codeword and its relatively long duration allow channel estimation at significantly higher signal-to-noise ratios a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.