Two-dimensional cross-track asymmetric target design for high-density bit-patterned media recording

In bit-patterned media recording (BPMR) channels at ultra high areal densities, the inter-track interference (ITI) is extremely severe, which significantly degrades the system performance. The partial-response maximum-likelihood (PRML) technique that uses a one-dimensional (1D) partial response target might not be able to cope with this severe ITI, especially in the presence of media noise and track mis-registration (TMR). This paper proposes a two-dimensional (2D) cross-track asymmetric target, based on a minimum mean-squared error approach, for high-density BPMR channels. Result indicates that the proposed 2D target performs better than previously proposed 2D targets especially when media noise and TMR is severe.