Equalization adaptation using timing detector

摘要

An equalization adaptation circuit comprises an equalizer, a transition determination circuit, a phase error circuit, a sequence recovery circuit, a phase error accumulator circuit, a transition accumulator circuit, and a controller circuit. The equalizer has adjustable parameters. The transition determination circuit determines observed transitions in an equalized signal output from the equalizer. A phase error circuit determines phase errors of the observed transitions. A sequence recovery circuit generates recovered digital data sequences. A phase error accumulator circuit accumulates the phase errors in respective association with pre-defined patterns matching the recovered digital data sequences containing observed transitions corresponding to the phase errors. A transition accumulator circuit accumulates a number of the observed transitions. A controller circuit controls the adjustable parameters of the equalizer based upon the accumulated phase errors and number of observed transitions.

主权项

1. A method of adjusting an equalizer in a digital communications circuit, the method comprising:
a) selecting at least one reference sequence for which equalization is to be optimized, each reference sequence containing a corresponding target bit transition; b) generating phase error signals corresponding to observed transitions in an equalized signal, the phase error signals indicating phase errors of the observed transitions relative to average transition timings; c) generating transition signals indicating the presence or absence of the observed transitions in unit intervals of the equalized signal; d) generating recovered data sequences from the equalized signal; e) for each reference sequence, accumulating the phase error signals corresponding to observed transitions contained in the recovered data sequences matching the reference sequence when the observed transitions match the target bit transition corresponding to the reference sequence; f) for each reference sequence, accumulating the transition signals indicating a total number of the observed transitions in the equalized signal; and g) adjusting the equalizer according to a predefined metric function based on the accumulated phase error signals and the total number of the observed transitions for each selected reference sequence.