NOISE-REDUCTION IN STATE-SPACE DIGITAL-FILTERS USING HIGH-ORDER ERRORFEEDBACK

A technique for the reduction of the output noise variance in state-sp ace digital filters is developed using a high-order error feedback con sisting of a finite impulse response (FIR) digital filter. First, the optimal error feedback structure using all of the elements of the coef ficient matrices in the FIR digital filter is derived. Next, the subop timal error feedback structures are shown; the elements of the coeffic ient matrices in the FIR digital filter are constrained to be either s ymmetric or antisymmetric. Finally, a numerical example is given to il lustrate the utility of the proposed technique.