Topic: Networks, Signals and Systems
An LTI system is minimum phase if
- A. All poles are inside unit circle
- B. All zeros are inside unit circle
- C. All poles are outside unit circle
- D. All poles and zeros are inside unit circle
Answer: D. All poles and zeros are inside unit circle
Explanation: A discrete-time linear time-invariant (LTI) system is defined as minimum phase if both the system and its inverse are causal and stable. For causality and stability, all poles of the system transfer function must lie strictly inside the unit circle. For its inverse to also be causal and stable, all zeros of the original system must also lie strictly inside the unit circle.