Method and controller for equalizing a received serial data stream

Abstract

A controller and methods for adaptively adjusting a dispersion compensation circuit in a receiver of a communication link are disclosed. The controller receives a signal from an error detector coupled to the receiver. The controller includes a logic engine that provides configuration information to the dispersion compensation circuit. The configuration information defines a digital filter in response to at least one tap constraint and at least one coefficient constraint. In an example embodiment, the logic engine generates a measure of residual inter-symbol interference and a measure of a noise enhancement penalty and iteratively provides a set of adjusted coefficient values that when applied in the digital filter will result in an equalized receiver output signal that minimizes a mathematical combination of the measure of the residual inter-symbol interference and the measure of the noise enhancement penalty. Alternatively, for bandwidth limited channels, the controller provides a predetermined set of coefficient values.