FIR filter windowing methods

Hi, I have a burning question want to ask.

Why windowing is not necessary if we have more than 100 coefficients for the FIR filter at a sampling rate of 0.1Hz?

Any hints and tips will be appreciated!

Answer 1

[Wayne King]

Can you be more specific? Are you talking about designing an FIR filter using the window method or applying a window to FIR filter coefficients.

The window method for FIR filter design typically begins with some idealized response, which has an infinite impulse response, truncating that response, and then applying a window to improve things like sidelobe behavior and enforce symmetry to ensure linear phase.

So what exactly are you having trouble with?

[John]

I do understand the steps of designing a FIR filter.

However my issue is if I'm given this problem on analog filter with impulse response h(t) = e−t2.

Which will be the design step can be omitted and why?

For me I think truncating the impulse response is not necessary. Am I right?

[Wayne King]

If you want to design an FIR filter, you have to have a finite number of filter taps.