Patent ID: 8774322

Claim:
A method, comprising: receiving a data signal including a plurality of symbols; filtering the plurality of symbols with a digital filter, the digital filter having a filter length; processing a portion of the plurality of symbols to define a geometric shape on a complex plane, the geometric shape including a centroid and a circumference; generating a correction signal from a difference between a first value and a second value, the first value being a first variance value associated with the portion of the plurality of symbols extending from the centroid of the geometric shape to the circumference of the geometric shape along a first axis, and the second value being a second variance value extending from the centroid of the geometric shape to the circumference of the geometric shape along a second axis, the first axis being orthogonal to the second axis, the first variance value corresponding to a square of a first standard deviation with respect to a first distribution of data along the first axis and the second variance value corresponding to a square of a second standard deviation with respect to a second data distribution along the second axis, the first and second distributions of data corresponding to the portion of the plurality of symbols; and adjusting the filter length of the digital filter based upon the correction signal.