Undoing the Noise Filter: the Inverse Noise Model

The viewer can (1) recover e from v by hand for H = 1/(1 − 0.8q⁻¹), (2) state what H⁻¹ is and when it exists (Lemma 3.1: 1/H(z) analytic in |z| ≥ 1, i.e. the zeros of H inside the unit circle), (3) compute H⁻¹ for the slide-8 example and for v = e + c e(t−1), and say why |c| < 1 is needed.