Method and apparatus for performing frame synchronization in an asymmetrical digital subscriber line (ADSL) system
US5995568A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1996 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Oct 28, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2656
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for performing DMT frame synchronization in an ADSL system begins by providing a training signal (82) to a receiver of the ADSL system (34). The training signal (82) is processed to result in a desired impulse response. The impulse response is used to reduce inter-symbol interference between time-adjacent DMT frames (100-108). The desired impulse response is used to calculate a frame misalignment value (.DELTA.T). The frame misalignment value (.DELTA.T) of the desired impulse response (84) is then utilized to adjust an internal counter of the receiver to perform frame alignment. The use of the training signal (82) and impulse response (84) to provide for both intersymbol interference reduction (FIG. 5) and frame synchronization (FIG. 8) provides for fast ADSL initialization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.