FIR filter structures having low sensitivity and roundoff noise

A class of structures for FIR filters is presented, which exhibits reduced coefficient sensitivity and superior roundoff noise properties as compared to the direct form realization. It is shown that using fixed-point arithmetic, these structures achieve the same accuracy and about the same roundoff noise as those obtained in the floating-point implementationn. The optimum structure to achieve the minimum roundoff noise can be found; in most cases near optimum results are easily obtained by simple permutations and combinations of the impulse response coefficients. While a serial form realization of these structures requires a certain amount of software complexity, a parallel form, on the other hand, does not require additional complexity.