(New page: == Memoryless Systems == A memoryless system is one that produces an output Y(t) that is purely dependent on the input at that specific time t. Memoryless System: y(t) = 2x(t) + 7t Sys...) |
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− | + | == Causal System == | |
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− | + | A causal system (non-anticipative system) is one that produces an output that is dependent on either present or past values of 't'. Therefore, a causal system does not produce an output x(t) based on any future value of 't'. Furthermore, we can conclude that all memoryless systems are causal because they only depend on a present value of 't'. | |
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− | == Causal System == | + | == Non-Causal System == |
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+ | A non-causal system is one that produces an output that is dependent on some future value of 't'. In addition to being dependent on a future value of 't', the system's output may also be dependent on a present or past value of t. | ||
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+ | Causal System: | ||
+ | y(t) = x(t-9) + 6 | ||
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+ | Non-Causal System: | ||
+ | y(t) = x(t+9) +6 | ||
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− | + | The first system is causal since it is dependent on a past value of 't'. However, the second system is non-causal because it depends on a future value of 't'. |
Latest revision as of 18:27, 16 September 2008
Causal System
A causal system (non-anticipative system) is one that produces an output that is dependent on either present or past values of 't'. Therefore, a causal system does not produce an output x(t) based on any future value of 't'. Furthermore, we can conclude that all memoryless systems are causal because they only depend on a present value of 't'.
Non-Causal System
A non-causal system is one that produces an output that is dependent on some future value of 't'. In addition to being dependent on a future value of 't', the system's output may also be dependent on a present or past value of t.
Causal System:
y(t) = x(t-9) + 6
Non-Causal System: y(t) = x(t+9) +6
The first system is causal since it is dependent on a past value of 't'. However, the second system is non-causal because it depends on a future value of 't'.