A Soft ITI Mitigation Method for Coded 2H2T BPMR Systems

To achieve an areal density (AD) of hard disk drives (HDDs) up to 4 Tb/in
²
, a bit-patterned magnetic recording (BPMR) system is one of the interesting candidates for the emerging magnetic recording technologies. Generally, intertrack interference (ITI) is a major problem for the BPMR system and it can deteriorate the overall system performance. Thus, this paper proposes the soft ITI mitigation method for coded two-head two-track (2H2T) BPMR systems. Specifically, the proposed method subtracts the estimated ITI signal (generated based on the soft decision obtained from a decoder for each turbo iteration) from the original readback signal during the turbo decoding process. Simulation results show that the proposed method outperforms the conventional method employing the hard decision to estimate the ITI signal at 2 and 2.5 Tb/in
²
.