A Simple 2-Head 2-Track Detection Method for Bit-Patterned Magnetic Recording Systems

Bit-patterned magnetic recording (BPMR) is a promising solution for future hard disk drive technologies. Generally, a two-dimensional (2D) interference composing of intersymbol interference and inter-track interference (ITI) is a serious problem in BPMR systems, especially at high areal densities. This paper proposes a simple 2-head 2-track (2H2T) data detection method in conjunction with the 1D target to alleviate the ITI effect. Specifically, the readback signal from the first read head is subtracted by the weighted readback signal of the second read head, and vice versa, before sending the refined readback signals to a 1D equalizer followed by a 1D detector to obtain the most likely input bits, where a weighting factor will be computed numerically. Experimental results demonstrate that the proposed system is superior to the conventional system with one read head using either 1D or 2D targets. Furthermore, we found that the proposed method is also robust to track mis-registration if compared to the conventional system with one read head.