A STUDY OF CLASS-I PARTIAL-RESPONSE SIGNALING FOR MAGNETIC RECORDING

Using a semianalytic technique based on the work of Agazzi and Seshadr i, we compare the performance of PR1, PR4, and EPR4 partial response s chemes on a magnetic recording channel, The technique includes the eff ect of imperfect equalization and, in the PR4 case, the effect of empl oying two interleaved Viterbi detectors, Assuming the Lorentzian chann el model and superposition, we use this technique to compare these sig naling schemes at medium and high recording densities. It is observed that, even with the trivial DC-free code employed, PR1 is superior to PR4 at recording densities beyond about S-c = 2.4 and superior to EPR4 beyond about S-c = 2.9, In addition, PR1 lends itself to difference m etric Viterbi detection, Our analytical results are supported by compu ter simulations.