Extending the Routes of the Soft Information in Turbo Equalization for Bit-Patterned Media Recording

This paper presents a new framework of turbo equalization (TE) to overcome 2-D intersymbol interference (2-D ISI) for bit-patterned media recording (BPMR). The BPMR has been developed for the next generation of hard disk drives aiming to extend storage density. One of the main challenges for the system is 2-D ISI, i.e., 1-D ISI from neighbor bits and intertrack interference from adjacent tracks. The conventional TE is the iterative process between an equalizer (or detector) and a decoder. We construct a new scheme of TE where the soft information from the decoder is fed back not only to the equalizer but, at the same time, also to the detector. The proposed scheme is to exploit full advantage of a priori information from the decoder. The results show that the proposed model is approximately 0.4 dB better than the conventional TE solution at 0% track misregistration.