Multiplierless implementation of recursive digital filters using a class of low sensitivity structures

One of the method of reducing coefficient sensitivity is that of coefficient translation. The structure is altered in such a way that the sensitivity with respect to the modified coefficients is reduced to a great extent compared to that with respect to the original coefficients. In low sensitivity structures the modified coefficients can be realized with multipliers of shorter wordlength i.e., in fewer number bits. When these are implemented in minimum numbers of signed powers of two (MNSPT) form, we have a multiplierless implementation These implementations are not associated with increase in the order of the filter that involves more number of shift registers, data paths, control circuits, etc., and hence, an increase in complexity i.e. indirect overheads.