Realisation techniques for primitive operator infinite impulse response digital filters

Realization techniques for infinite impulse response (IIR) digital filters based on the primitive operator graph synthesis method are presented. The approach exploits the redundancy present in the filter multiplier structure when the coefficients are invariant, allowing partial result reuse throughout the filter structure. Results are presented for a range of elliptic filters with varying wordlength and order, realized using direct form, parallel and cascade structures. These show significant savings when compared with the equivalent canonical signed digit multiplier coding scheme