1. A method for processing a composite communication signal comprising two or more simultaneously received signals of interest, the method comprising: detecting first symbols, corresponding to a first signal of interest, from the composite communication signal, using first processing weights calculated from a square-root covariance matrix and a net channel response for the first signal of interest, wherein the square-root covariance matrix represents impairment covariance or data covariance for the composite communication signal; calculating a reconstructed version of the first signal of interest, based on the detected first symbols; generating an updated communication signal by subtracting the reconstructed version of the first signal of interest from the composite communication signal; and updating the square-root covariance matrix to obtain an updated square-root covariance matrix corresponding to the updated communication signal.