Howtosignalprocessing
- Why ideal filters are non causal?
- Is an ideal low pass filter causal?
- What is FIR in digital signal processing?
Why ideal filters are non causal?
Since the filter characteristic H(jω) is an even function, it is typically only shown for ω > 0. Figure A11. 1 shows that h(t) exists for t < 0 whereas the input δ(t) occurs only at t = 0; this indicates that such an ideal filter is a noncausal system.
Is an ideal low pass filter causal?
As a consequence: an ideal filter cannot be causal. Problem: we want to determine a causal Finite Impulse Response (FIR) approximation of the ideal filter.
What is FIR in digital signal processing?
In signal processing, a finite impulse response (FIR) filter is a filter whose impulse response (or response to any finite length input) is of finite duration, because it settles to zero in finite time.
