Characterizing a non-LTI system

1. What is LTI and non LTI system?
2. How is an LTI system characterized?
3. Do non LTI systems have impulse response?
4. How do you find the LTI system is stable or not?

What is LTI and non LTI system?

Linear time-invariant systems (LTI systems) are a class of systems used in signals and systems that are both linear and time-invariant. Linear systems are systems whose outputs for a linear combination of inputs are the same as a linear combination of individual responses to those inputs.

How is an LTI system characterized?

Any system in a large class known as linear, time-invariant (LTI) is completely characterized by its impulse response. That is, for any input, the output can be calculated in terms of the input and the impulse response.

Do non LTI systems have impulse response?

Also, since δ[n] is even, any non-LTI system's impulse response, for example, δ[1−n], will equal δ[n−1] which corresponds the impulse response of an LTI system.

How do you find the LTI system is stable or not?

Time Domain Condition for the Stability of LTI Discrete-Time Systems. For a system, when the bounded input sequence always produces a bounded output sequence, then the system is said to be stable system.