Estimation of pole zero displacements of a digital filter due to coefficient quantization

Abstract

An analytical technique for estimating the displacement of poles and zeros of a digital filter due to multiplier coefficient quantization is presented. The proposed technique allows rapid evaluation of quantization effects in different realizations of a given transfer function. Also advanced here is a simple extension of the method to determine, a priori, coefficient word lengths which insure that the polezero movements will remain within prescribed bounds. Examples illustrating the technique are included.