m (Memory)
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==[[Causality_Old Kiwi]]==
 
==[[Causality_Old Kiwi]]==
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A causal system has outputs that only depend on current and/or previous inputs.
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*Example of a '''causal''' system:
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<math>y(t) = x(t) + x(t - 1)</math>
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*Example of a '''non-causal''' system:
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<math>y(t) = x(t) + x(t + 1)</math>
  
 
==[[Stability_Old Kiwi]]==
 
==[[Stability_Old Kiwi]]==

Revision as of 22:54, 17 June 2008

The six basic properties of Systems_Old Kiwi

Memory_Old Kiwi

A system with memory has outputs that depend on previous (or future) inputs.

  • Example of a system with memory:

$ y(t) = x(t - \pi) $

  • Example of a system without memory:

$ y(t) = x(t) $

Invertibility_Old Kiwi

An invertible system is one in which there is a one-to-one correlation between inputs and outputs.

  • Example of an invertible system:

$ y(t) = x(t) $

  • Example of a non-invertible system:

$ y(t) = |x(t)| $

In the second example, both x(t) = -3 and x(t) = 3 yield the same result.

Causality_Old Kiwi

A causal system has outputs that only depend on current and/or previous inputs.

  • Example of a causal system:

$ y(t) = x(t) + x(t - 1) $

  • Example of a non-causal system:

$ y(t) = x(t) + x(t + 1) $

Stability_Old Kiwi

Time Invariance_Old Kiwi

Linearity_Old Kiwi

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