IIR DFE updating gain and time constants using LMS equations

摘要

A method for adapting a mixed signal Infinite Impulse Response (IIR) Decision Feedback Equalizer (DFE) using pivot taps and monitor taps is disclosed. The method includes, for a given IIR path for a received signal, updating gain of the given IIR path using a respective pivot tap error-data correlation with a first Least Mean Square (LMS) update equation; and updating a time constant of the given IIR path using a respective monitor tap error-data correlation with a second LMS update equation.

主权项

1. A Decision Feedback Equalizer (DFE) comprising:
a set of data slicers connected to provide a signal to a data delay line having a plurality of digital delay blocks, the set of data slicers further connected to receive an input signal that has been provided through an adder; and a first Infinite Impulse Response (IIR) tap for a first IIR path, the first IIR tap comprising a first digital-to-analog converter (DAC) and a first filter, the first IIR tap being connected to receive a signal output from a respective digital delay block that has been selected for a pivot tap for the first IIR path and further being connected to provide a correction signal to the adder; in which coefficients for the first DAC are connected to be updated using a respective pivot tap error-data correlation with a first Least Mean Square (LMS) update equation and coefficients for the first filter are connected to be updated using a respective error-data correlation for a monitor tap for the first IIR path with a second LMS update equation; and at least one additional IIR tap for a respective IIR path, each additional IIR tap including: a respective DAC and a respective filter; each additional IIR tap being connected to receive the signal from a respective digital delay block that has been selected for a pivot tap for the additional IIR path and to provide a respective correction signal to the adder; in which coefficients for the respective DAC are connected to be updated using another respective pivot tap error-data correlation with the first Least Mean Square (LMS) update equation; and coefficients for the respective filter are updated using another respective error-data correlation for a monitor tap for the additional IIR path with the second LMS update equation.