Decision feedback equalizer

摘要

In a decision feedback equalizer, at least one of weighting devices that has a tap coefficient an absolute value of which is relatively larger than absolute values of tap coefficients of other weighting devices is referred to as a main weighting device, and delay elements are disposed asymmetrically on signal processing paths or updating paths of the tap coefficients of the weighting devices in such a manner that an updating interval of the tap coefficient of the main weighting device is shorter than updating intervals of the tap coefficients of the other weighting devices.

主权项

1. A decision feedback equalizer comprising:
a plurality of weighting devices on a feed forward side each of which weights an input signal by multiplying the input signal by a tap coefficient directly or through one or more delay elements; a plurality of weighting devices on a feedback side each of which weights an output signal by multiplying the output signal by a tap coefficient through one or more delay elements; an adder adding all signals passing through the weighting devices; a detector detecting a data symbol based on an addition result of the adder and outputting the output signal; a subtractor calculating a difference between an input signal and the output signal of the detector; and a tap coefficient updating portion updating the tap coefficient by multiplying a subtraction result of the subtractor by an updating coefficient and outputting an updated tap coefficient to each of the weighing devices, wherein at least one of the weighting devices that has the tap coefficient an absolute value of which is relatively larger than absolute values of the tap coefficients of the other weighting devices is referred to as a main weighting device, and the delay elements are disposed asymmetrically on signal processing paths or updating paths of the tap coefficients of the weighting devices in such a manner that an updating interval of the tap coefficient of the main weighting device is shorter than updating intervals of the tap coefficients of the other weighting devices.