Digital transmission systems
US4484336A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 1982 |
| Grant date | Nov 20, 1984 |
| Priority date | — |
| Expiry date | May 21, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03019
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Feedback equalization is employed for digital repeaters of transmission systems having twisted-wire pairs, in order to reduce intersymbol interference while minimizing near-end crosstalk gain. Previously the incoming signal was selectively amplified at the higher frequencies in order to negate intersymbol interference, with subsequent near-end crosstalk gain. According to the present invention the intersymbol interference element of an incoming signal is cancelled, prior to amplification in an adder by a compensation signal derived from the output signal of a regenerator and a retimer. An output stage serves to amplify and shape the resultant signal to a form suitable for transmission. The compensation signal comprises the inverted output of a filtering and scaling network.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.