1. A method of controlling crosstalk between channels of a communication system, comprising: estimating crosstalk between channels of the system; generating a compressed representation of the crosstalk estimates; and generating compensated signals based on the compressed representation of the crosstalk estimates; wherein the compressed representation comprises a value array and an index array, the value array comprising selected values from each of a plurality of rows of a matrix representation of the crosstalk estimates and the index array identifying locations of the selected values in the matrix representation of the crosstalk estimates.