Performance comparison between PR1 and PR4 signaling on high-density magnetic recording channels

We present a technique based on a result of Agazzi and Seshadri for comparing the performance of various partial response schemes on a magnetic recording channel. The technique includes the effect of imperfect equalization and, in the PR4 case, the effect of employing two interleaved Viterbi detectors. Assuming the Lorentzian channel model and superposition, we use this technique to compare PR1 and PR4 signaling at medium and high recording densities. It is observed that PR1 provides the superior performance at a user density of S_u=2.5. Our analytical results are supported by computer simulations