A method of signal processing for use in reading data includes determining first and second waveforms, determining a cross-correlation of the first waveform with the second waveform, and determining a specific time delay corresponding to a maximum peak in the cross-correlation function. A filter is then applied based on the specific time value. The filter combines the first waveform and the second waveform so as to generate a filter output waveform including coherent information representing the data and including reduced incoherent noise.