Viterbi detection for partial-response channels with colored noise

This paper is concerned with improving the performance of a Viterbi detector matched to a partial response signal corrupted by additive Gaussian colored noise. The detector operates on a trellis that contains four times the normal number of states. Simulation results are presented for the case of a Lorentzian channel equalized to either an EPR4 or PR5 digital magnetic recording channel. The results suggest a method whereby a single Viterbi detector operating on a PR5 trellis with four times the number of states can be used to minimize the effects of thermal asperities (TAs) and also yield good performance in the absence of these TAs.