Method and apparatus for time domain equalization in an XDSL modem
US7076010B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2001 |
| Grant date | Jul 11, 2006 |
| Priority date | — |
| Expiry date | Apr 3, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03585
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The current invention provides a method and apparatus for time domain equalization in an XDSL modem. A received communication channel is analyzed to determine the highest frequency component thereof. Typically, there is an inverse relationship between the length of a subscriber line and the highest frequency component over which communications can be supported. In response to the frequency determination, the sampling rate for the channel is reduced to the lowest sample rate consistent with maintaining signal integrity on the highest frequency component of the channel. The sampling rate reduction may accomplished in the analog portion of the receive path, e.g. the analog-to-digital converter (ADC) or in a digital decimator coupled thereto. Concurrently the demodulator complexity is also scaled back. Where the XDSL protocol is digital multi-tone (DMT) the input sample size to the discrete Fourier transform (DFT) engine is reduced accordingly. With these adjustments in place TEQ resources may be scaled inversely. Thus as line length increases and the available bandwidth on the subscriber line is reduced more TEQ resources are made available to deal with the increased delay interval ov…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.