A method and apparatus are provided for performing electronic equalization
in optical communication systems. Coefficient values in equalizers, such
as feed forward equalizers or decision feedback equalizers, are updated
using higher-order algorithms in the Least-Mean-2Nth-Order family. An
optical receiver includes a photo-detector for converting a received
optical signal to an electrical signal; and an equalizer for removing
intersymbol interference from the electrical signal, wherein coefficients
of the equalizer are updated based upon a least-mean 2N.sup.th-order
(LMN) algorithm (N is greater than one). Feed forward equalizer and
decision feedback equalizer implementations are disclosed. The
non-symmetric nature of optical noise is addressed by varying A slicer
threshold based on an incoming signal distribution to reduce bit errors.