The impulse response of the ideal delay system is ht t td F

The impulse response of the ideal delay system is h(t) = (t td). For what values of td will the delay system be causal?

Solution

if the system is casual means, thsystem output depends upon past and present input.

t-td<=t for this condition the system to be casual

so -td<=0

-d<=0 or d>=0

so the system is casual for d>=0