Fir filter design example problems

1. What is FIR filter equation?
2. What is the procedure for designing FIR filter using Windows?
3. How do you calculate filter length?

What is FIR filter equation?

The impulse response h[n] can be calculated if we set x[n] = δ[n] in Equations 15-20 and 15-21, where δ[n] is the Kronecker delta impulse. The impulse response for a FIR filter then becomes the set of coefficients b_n, as follows: (15-22) for n = 0 to N.

What is the procedure for designing FIR filter using Windows?

To design an FIR filter by windowing, you first decide on an ideal frequency response and calculate the impulse response of the ideal frequency response. You then truncate the impulse response to produce a finite number of coefficients.

How do you calculate filter length?

The value of j is defined by the user and it determines the filter length. So if j=1, samples x(n-1), x(n), x(n+1) , are taking into account, that is 3 samples (N) are used. So the filter length here is 3. A filter is most defined in terms of its filter order.