A method and system of efficiently processing a discrete time input signal having a plurality of input signal samples that occur at a first clock rate into a discrete time output signal having a second clock rate that is R times the first clock rate is presented. The method includes receiving the input signal and filtering the input signal with an N-taps finite impulse response (FIR) filter having N filter coefficients. The method reduces the number of required operations and reduces computational errors in the filtering and interpolation of discrete input signals.