Multiplier-free IIR filter realization using periodically time-varying state-space structure. I. Structure and design

A multiplier-free realization for IIR filters is proposed. A given target IIR filter is implemented in cascade or parallel form of biquad units. Each biquad unit is realized with a periodically time-varying (PTV) state-space system. The system uses a higher order PTV state-space (PTV-SS) structure operating at an elevated signal rate to realize each biquad. The coefficients of the PTV-SS structure used in the realization are restricted to a few power-of-two values. Therefore, such a structure can be implemented without any hardware multiplier. A brief analysis of precision and round-off error for the realization is presented. Examples show that the frequency response of the proposed realization matches very well with that of the target filter.<
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