Equalizer training in the presence of network impairment
US6570917B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1999 |
| Grant date | May 27, 2003 |
| Priority date | — |
| Expiry date | Jun 22, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03783
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Analog modems are enabled to better learn the slicing levels employed at the interface to a digital transmission network by reducing the effects of the various noise sources. Initially a training sequence is received to preliminarily adjust the analog modem's equalizer. Thereafter, a special training sequence, protected against intersymbol interference, is employed to collect samples of each slicing level, to ascertain the least mean squared value of each slicing level from the received samples and to obtain the channel's impulse response at each slicing level. To mitigate the effects of robbed bit signaling that may be employed in the digital transmission network, an array of slicers is provided to determine which bit position is being robbed and to base level learning on samples obtained from the non-robbed positions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.