What exactly does causal signal mean?
Causality,as I see it is a property of a system wherein the output at PRESENT is dependent ONLY on PAST and PRESENT values of input.Here we have a reference of Output signal Time to define PAST & PRESENT for an input.
Since an isolated signal doesn't have a concept of a STATE,how can we define past or present for a signal?
If ideas of Past & Present aren't defined for a signal,how can the idea of causality be defined for signals?
Here the definition is given but I 'm not able to get a feel of Causality of a signal?
I've a follow-up question which I've put up here.