Patent ID: 6188722
Filing Date: 2001-02-13
Classification: H04L

Abstract:
A blind convergence process for an adaptive decision feedback equalizer having a 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, said blind convergence process comprising the steps of:(a) performing a clustering process comprising:(a1) updating the forward tap coefficients of the forward filter;(b) performing a decision directed process for a predefined set of QAM indexes having values n.sub.1, n.sub.2, . . . , n.sub.m, comprising:(b1) 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(b2) updating the feedback tap coefficients of the feedback filter for the QAM index n.sub.i selected from the predefined set of QAM indexes;(c) determining if the equalizer has converged, and(d) repeating steps (b1), (b2) and (c) for a next QAM index n.sub.i+1 of the predefined set of QAM indexes until the equalizer has converged to the highest operable QAM index.