A number of papers have recently been published on the concatenation of an
outer code with a partial response (PR) channel, where the outer code is a
turbo code, a convolutional code, or a low-density parity-check code, This
paper deals with the second case, assuming EPR4 and modified extended EPR4
(MEEPR4) partial response (PR) targets. The goals in this work include 1) t
he joint optimization of interleaver and precoder for a fixed outer convolu
tional code and PR target, 2) the choice of optimal code rate for both PR t
argets assuming a Lorentzian model, and 3) an assessment of the performance
of these codes in the presence of thermal asperities. We introduce mathema
tical and algorithmic tools for accomplishing these goals and present simul
ation results that support our approach, Among the positive results is the
ability to lower the well-known error rate floor of these concatenated sche
mes for arbitrary PR channels.