# Zero Order Hold with polyphase resampler

I'm trying to design a FIR filter(direct form) the coefficient of which will be used to design a polyphase resampler that does Zero-Order Hold resampling. If the direct form impulse response is triangular, then we get a linear interpolator.

Is it possible to imagine a filter response that would produce a ZOH interpolator? I have some constraints that prevent a simple MATLAB's repelem() based ZOH implementation.

• Zero-order hold means you're not actually interpolating/filtering, so the filter taps you're looking for is simply [1]. – Marcus Müller Oct 19 '16 at 18:13
• @MarcusMüller, ZOH most certainly is an interpolator. just not a very good one. – robert bristow-johnson Jan 12 '17 at 17:44
• @robertbristow-johnson well, that's certainly true :) My bad! – Marcus Müller Jan 12 '17 at 19:49