Consider a filter described by the following recursive difference equation:
y(k) = x(k) - 0.2y(k-1) - 0.8y(k-2)
You can easily specify and implement this filter in time domain using unitDelay blocks. The filter input is x(k) and the filter output is y(k). The intermediate states are y(k-1) and y(k-2). The filter can be implemented as:
The Time Between Pulses parameter for the pulseTrain block must be greater than or equal to the simulation time step. An arbitrary value of 1 is assigned to input x.