I'm learning DSP slowly and trying to wrap my head around some terminology:
Question 1: Suppose I have the following filter difference equation: $$y[n] = 2 x[n] + 4 x[n-2] + 6 x[n-3] + 8 x[n-4]$$
There are 4 coefficients on the right-hand side. Are the "number of taps" also 4? Is the "filter order" also 4?
Question 2: I am trying to use the MATLAB
fir1(n, Wn)function. If I wanted to create a 10-tap filter, would I set $n=10$?
Question 3: Suppose I have the following recursive (presumably IIR) filter difference equation: $$y[n] + 2 y[n-1] = 2 x[n] + 4 x[n-2] + 6 x[n-3] + 8 x[n-4]$$
How would I determine the "number of taps" and the "filter order" since the number of coefficients differ on the left-hand and right-hand sides?
Question 4: Are the following logical if-and-only-if statements true?
- The filter is recursive $\iff$ The filter is IIR.
- The filter is nonrecursive $\iff$ The filter is FIR.