Sequential blind convergence process in an adaptive decision feedback equalizer
US6188722A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1998 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Apr 29, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03732
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A blind convergence process for an adaptive decision feedback equalizer having an quadrature amplitude modulation (QAM) slicer, a forward filter defined by a plurality of forward tap coefficients and a feedback filter defined by a plurality of feedback tap coefficients. The blind convergence process includes the step of initializing the forward tap coefficients of the forward filter and the feedback tap coefficients of the feedback filters with predetermined values. The QAM slicer operates in two modes: a clustering mode and a decision directed mode. The clustering mode includes the step of updating only the forward tap coefficients of the forward filter for a prescribed start-up QAM index (such a 4 QAM). The decision directed mode is predefined for set of QAM indexes having values n.sub.1, n.sub.2, . . . n.sub.m, and includes: updating the forward tap coefficients of the forward filter for a QAM index n.sub.i selected from the predefined set of QAM indexes, and updating the feedback tap coefficients of the feedback filter for the QAM index n.sub.i selected from the predefined set of QAM indexes. The decision directed processing steps are repeating the next QAM index n.sub.i+1 of t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.