An Inter-Track Interference Mitigation Technique Using Partial ITI Estimation in Patterned Media Storage

The readback signal of patterned media storage (PMS) is corrupted by a two-dimensional interference consisting of inter-symbol interference (ISI) and inter-track interference (ITI). In this paper, we apply the turbo equalization to mitigate the ITI effects. The codeword of the outer code is divided and then written on three separate tracks. After the first iteration, the bit estimates from the outer code provide partial ITI estimates for the branch metric computation in the soft-output viterbi algorithm (SOVA) detectors. Unlike previous works, the number of states of the channel trellis is due to the ISI only since the ITI information is not embedded in the parallel branches. When compared with the modified SOVA detectors with multi-parallel branches, simulation results show that a significant performance gain is achieved by our proposed method.