§Discrete
time LTI (Linearity and Time Invariance) systems can be
classified into FIR and IIR.
§An
FIR filter has impulse response h(n) that extends only over
a finite time interval, say 0≤ n ≤ M, and is identically
zero beyond that:
§ {h0, h1, h2 . . . , hM, 0, 0, 0 . .
.}
M is referred to as the filter order.
§The output y(n) in FIR is simplified to the
finite-sum form:
§
§
§
§or, explicitly
§