Some Practical Consideration in the Realization of Linear Digital Filters

The literature on sampled-data filters, although extensive on design methods, has not treated adequately the important problems connected with the actual realization of the obtained filters with finite arithmetic elements. Beginning with a review of the traditional design procedures a comparison is made between the different canonical realization forms and their related computational procedures. Special attention is directed to the problems of coefficient accuracy and of rounding and trucation effects . A simple expression is derived which yields an estimate of the required coefficient accuracy and which shows clearly the relationship of this accuracy to both sampling rate and filter complexity.