How do we test the causality of a signal?

[magnetra]

How do we test the causality of a signal?

 

[mario82]

Re: Casuality

A signal is causal when its value is null for moments of time t<0 (or n in discrete time).

In order to know if the signal is causal only you must know the value this one just before applying it. If he is different from zero, the signal is causal.GFor example, in an electrical circuit all the voltages and currents are causals because they are null until that a signal is applied.

Regards.

 

[bmos]

Casuality

Yes, for instance a system is causal if its impulse response is zero for all times < 0.

 

[Kral]

Re: Casuality

In qualitative terms, a system is causal if its output depends only on the current and past inputs. This definition applies to both analog (continuous) and digital (Sampled data) systems. Otherwise, the system would be a true predictor. If you could build a physical non-causal system, you could make a killing in the stock market. A definition given by Allen Appenheim in one of his video courses is "A causal system is one that doesn't move until you kick it".