Digital receiver with noise filter which also serves as a feedback filter providing intersymbol interference reduction
US5761243A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | May 3, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03146
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A receiver for transmitted signals which represent digital symbol values includes a low-pass filter to minimize transmission noise by reducing the receiver bandwidth. However, this creates pulse distortion which can cause intersymbol interference when the filtered signal is supplied to a symbol detector. Such interference is minimized by the inclusion of a feedback loop between the output of the symbol detector and the input to the filter, in which a detected symbol is multiplied by correction factor and supplied to a subtractor where it is subtracted from the signal to be filtered. The result of the subtraction is supplied to the filter. The noise reduction filter is thus also used for matching the intersymbol distortion characteristic of a filtered detected symbol to the intersymbol distortion characteristic of a filtered received signal pulse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.