Pipelining in direct form recursive digital filters with periodically time-varying coefficients

We propose a pipelined realization of direct form recursive digital filters with periodically time-varying coefficients. At first, we present the direct form recursive digital filter as a state-space filter, afterwards, we derive an equation for block-state update computation, finally, we use a block processing approach to get the equation for block output computation. The proposed realization is suitable for implementation in the VLSI form