Autoregressive (AR) Process

Look at 2.1 Rational Power Spectra.

$$b_0=1,b_k=0,k>0$$

Meaning that we are left with

$$H(z)=\frac{1}{A(z)}$$

And this gives us the following difference equation for the input-output relationship

$$x(n)+\sum _{k=1}^p{a}_{k}x(n-k)=w(n)$$

Meaning that the Noise-Whitening Filter for generating the innovations process is an all-zero filter.