Impulse response

Given the following transfer function:

$$H(z)=\frac{(1-z^{-1})(1+z^{-1})}{1-1.1314z^{-1}+0.64z^{-2}}$$

• To enter the system infomration

  >> num=conv([1 -1],[1 1])
  
  num =
  
       1     0    -1
  
  >> den=[1 -1.1314 0.64]
  
  den =
  
      1.0000   -1.1314    0.6400
  

  The conv function will multiply the to first-order polynomials in the numerator to give you your second-order numerator polynomial.
• To plot the impulse response

  >> h=dimpulse(num,den);
  >> stem(0:length(h)-1,h)
  

  If you only used dimpulse without anything on the left, the function will automatically plot the impulse response, but it uses the stairs function. To store the values and plot them using the impulse function, you need to store the output into some variable. The first argument of the stem function, 0:length(h), is used to generate the values 0, 1, 2, ..., to the length of h.

  Figure 6: Impulse response