An important representation for discrete-time linear systems is the
The state-space representation is especially powerful for multi-input, multi-output (MIMO) linear systems, and also for time-varying linear systems (in which case any or all of the matrices in Eq. (E.1) may have time subscripts ) . State-space models are also used extensively in the field of control systems .
An example of a Single-Input, Single-Ouput (SISO) state-space model appears in §5.13.5.