Causal signals and causal system

  • Thread starter reddvoid
  • Start date
  • #1
118
1
Is there a difference between causal signal and causal system ?
I got this doubt because

consider a system h(t) whose out put depends on present and past inputs only for all t (- infinity to + infinity ) so this system is a causal system

now if we treat this as a signal and since it exists from -infinity to+ infinity so it will be a non-causal signal. . . .

which one is correct ?
 

Answers and Replies

  • #2
193
17


Causality in systems makes the most sense. Causality in signals doesn't make that much sense.

Causality in systems determines whether a system relies on future information of a signal x[n+1].

When talking about "causality" in signals, we mean whether they are zero to the left of t=0 or zero to the right of t=0.

A causal signal is zero for t<0
A non-causal zero has values present for t<0.
Anti-causal signals are zero for t>0.

However, the reason why this doesn't really make sense is that if you have a signal, the time t=0 can be chosen arbitrarily.
 
  • Like
Likes rajendiran s
  • #3
118
1


Got it :) thank you for clarifying :)
 

Related Threads on Causal signals and causal system

  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
3
Views
24K
  • Last Post
Replies
2
Views
5K
  • Last Post
Replies
2
Views
5K
  • Last Post
Replies
9
Views
39K
Replies
8
Views
4K
  • Last Post
2
Replies
45
Views
1K
  • Last Post
Replies
3
Views
2K
Replies
5
Views
8K
Replies
1
Views
1K
Top