PG1995
Active Member
Hi
Could you please help me with these queries? The Q1 is given below. Thank you very much and please don't forget I'm new to this stuff.
Q1:
A causal system is one which responds only during or after an input signal is applied. Or, as the **broken link removed**, "Any system for which the zero-state response occurs only during or after the time in which it is excited is called a causal system".
But if I were to define it then I would say, a causal system is one whose output, y(t), does not depend on the future value of an input signal, x(t), or its some future output value. A causal system should always use present or previous value of an input signal and/or some previous output value. For instance, this equation is for a causal system, y(t)=x(t)+x(t-1). And this one is for a non-causal system, y(t)=x(t)+x(t+1)+y(t+1); you can see that the x(t+1) and y(t+1) expect future values. In other words, if you want to know the output's value at t=3 then you must first know its input signal's value at t=3 and its output value t=3. Such a system cannot implemented in real-time environment.
Regards
PG
Could you please help me with these queries? The Q1 is given below. Thank you very much and please don't forget I'm new to this stuff.
Q1:
A causal system is one which responds only during or after an input signal is applied. Or, as the **broken link removed**, "Any system for which the zero-state response occurs only during or after the time in which it is excited is called a causal system".
But if I were to define it then I would say, a causal system is one whose output, y(t), does not depend on the future value of an input signal, x(t), or its some future output value. A causal system should always use present or previous value of an input signal and/or some previous output value. For instance, this equation is for a causal system, y(t)=x(t)+x(t-1). And this one is for a non-causal system, y(t)=x(t)+x(t+1)+y(t+1); you can see that the x(t+1) and y(t+1) expect future values. In other words, if you want to know the output's value at t=3 then you must first know its input signal's value at t=3 and its output value t=3. Such a system cannot implemented in real-time environment.
Regards
PG
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