Effect of Reader Sensitivity Rotation in TDMR With Head Skew

Abstract

Two-dimensional magnetic recording (TDMR) by shingled magnetic recording (SMR) draws attention as a technology to increase the recording densities in hard disk drive (HDD). The magnetization pattern is curved by the write field at the corner of the writer in SMR, and the information to R/W channel performance is feared. Therefore, it is possible that the bit error rate (BER) performance is improved by fitting reader sensitivity to the bit shape. In this paper, we evaluate the effect of reader sensitivity rotation in the TDMR R/W channel with head skew under a specification of 4 Tbit/inch 2 by computer simulation applying the low-density parity-check (LDPC) coding and iterative decoding system with the two-dimensional finite impulse response (TD-FIR) filter. The results show that the rotated reader sensitivity fits the recorded bit magnetization shape and the error-free skew range increases to −3 ~ 6 degrees. Therefore, the reader sensitivity rotation is considered to be an effective way to improve the skew margin in TDMR system. Index Terms-Two-dimensional magnetic recording (TDMR), Shingled magnetic recording (SMR), Reader sensitivity rotation.