Exercise: Properties of linear discrete time systems
Consider the following discrete time system

where

In this problem, we will explore some of the properties of this discrete time system as a function of the parameters, the initial conditions, and the inputs.
Assume that the off diagonal element
and that there is no input,
. Write a closed form expression for the output of the system from a nonzero initial condition
and give conditions on
and
under which the output gets smaller as
gets larger.
Now assume that
and write a closed form expression for the response of the system from a nonzero initial conditions. Given a condition on the elements of
under which the output gets smaller as
gets larger.
Write a MATLAB program to plot the output of the system in response to a unit step input,
,
. Plot the response of your system with
and
given by