Track Mis-Registration Estimator Based on K-Means Algorithm for Bit-Patterned Media Recording

Bit-patterned media recording (BPMR) has been considered among the key technologies to extend recording densities to 1 Tb/in2 and beyond. However, the BPMR system encounters the challenges of two-dimensional intersymbol interference and track mis-registration (TMR). In this article, we propose a TMR estimator based on the $K$ -means algorithm for estimating the TMR levels and preventing the performance degradation of the BPMR system. The TMR estimator calculates the distances between the centroid of the readback signal and predetermined centroids according to the TMR level. The equalizer coefficients and partial response target are adjusted to the corresponding TMR level. At a bit error rate of 10−3 and a TMR of 10%, the proposed detection scheme performs better by approximately 1 dB in comparison with the conventional detection.