Systems and methods for non-casual channel equalization in an asymmetrical noise environment
US6961390B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 2002 |
| Grant date | Nov 1, 2005 |
| Priority date | — |
| Expiry date | Nov 19, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/061
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method are provided for non-causal channel equalization in a communications system. The method comprises: receiving a non-return to zero (NRZ) data stream input; establishing thresholds to distinguish a first bit estimate; comparing the first bit estimate in the NRZ data stream to a second bit value received prior to the first bit, and a third bit received subsequent to the first bit; in response to the comparisons, determining the value of the first bit; tracking the NRZ data stream inputs in response to sequential bit value combinations; maintaining long-term averages of the tracked NRZ data stream inputs; adjusting the thresholds in response to the long-term averages; and, offsetting the threshold adjustments to account for the asymmetric noise distribution. Two methods are used to offset the threshold adjustments to account for the asymmetric noise distribution: forward error correction (FEC) decoding and tracking the ratio of bit values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.