IIR/FIR filtering before decimation?

1. In which case do we choose FIR filter and IIR filter?
2. Which has faster response IIR or FIR filters?
3. Why IIR filters are not reliable?
4. Which filter is used in decimation and interpolation?

In which case do we choose FIR filter and IIR filter?

Advantages and Disadvantages of FIR and IIR Filters

IIR filters are well suited for applications that require no phase information, for example, for monitoring the signal amplitudes. FIR filters are better suited for applications that require a linear phase response.

Which has faster response IIR or FIR filters?

Therefore, an IIR filter can provide a significantly faster and more efficient filtering operation than an FIR filter. You can design FIR filters to provide a linear-phase response.

Why IIR filters are not reliable?

The bad of IIR: IIR filters can become unstable. For an impulse response, the output of an FIR will always settle back to 0. IIR filters have a feedback loop so they will accumulate rounding and noise error.

Which filter is used in decimation and interpolation?

11.2 Polyphase Filter Structure and Implementation. Due to the nature of the decimation and interpolation processes, polyphase filter structures can be developed to efficiently implement the decimation and interpolation filters (using fewer number of multiplications and additions).