A method includes modeling a design of a memory channel to provide a plurality of transfer functions associated with the design and multiplying an input spectrum with each of the transfer functions to provide a plurality of results. The method further includes summing the results to provide an output spectrum for the design, performing an inverse Fast Fourier Transform (FFT) on the output spectrum to provide an output signal for the design, and determining a bit error rate (BER) for the design based on the output signal.