A Study on Optimal BAR in Array Head Reading

Two-dimensional magnetic recording (TDMR), which combines shingled magnetic recording (SMR) with 2-D signal processing attracts attention from the hard disk drive industry. SMR is a magnetic recording system in order to increase the track density by writing tracks without the guard band. Therefore, the influences of writing and reading intertrack interferences (ITIs) deteriorate the quality of reproducing waveforms. Additionally, degradation of track due to overwriting and crosstalk from the adjacent tracks due to the width of reader sensitivity. The equalization using 2-D finite impulse response filter for the waveforms from three adjacent tracks is proposed as a method to reduce the influence of reading ITIs. In this paper, we evaluate the bit aspect ratio (BAR) in TDMR read/write channel under a specification of 4 Tb/in2 using bit error rate of the low-density parity-check (LDPC) coding and iterative decoding system obtained by computer simulation. The results show that the suitable BAR in array head reading is 2.0.

[1]  Y. Nakamura,et al.  Nonbinary LDPC Coding and Iterative Decoding System With 2-D Equalizer for TDMR R/W Channel Using Discrete Voronoi Model , 2013, IEEE Transactions on Magnetics.

[2]  Yasuaki Nakamura,et al.  Influence of Writing ITI Effects in Shingled Magnetic Recording , 2013, IEEE Transactions on Magnetics.

[3]  Robert G. Gallager,et al.  Low-density parity-check codes , 1962, IRE Trans. Inf. Theory.

[5]  Yasuaki Nakamura,et al.  Performance Evaluation of Neuro-ITI Canceller Using a Modified Writing Process for TDMR , 2013, IEICE Trans. Electron..

[6]  E. Kretzmer,et al.  Generalization of a Techinque for Binary Data Communication , 1966 .

[7]  Y. Nakamura,et al.  Iterative Decoding Using Attenuated Extrinsic Information from Sum-Product Decoder for PMR Channel With Patterned Medium , 2007, IEEE Transactions on Magnetics.

[8]  Y. Okamoto,et al.  Effect of Reader Sensitivity Rotation in TDMR With Head Skew , 2016, IEEE Transactions on Magnetics.

[9]  H. Muraoka,et al.  Finite-Element and Micromagnetic Modeling of Write Heads for Shingled Recording , 2010, IEEE Transactions on Magnetics.

[10]  Yasuaki Nakamura,et al.  Iterative decoding algorithm using attenuated information in PMR with bit-patterned medium , 2008 .

[11]  R. Wood,et al.  Parametric optimization for terabit perpendicular recording , 2003, Joint NAPMRC 2003. Digest of Technical Papers.

[12]  Yoshihiro Okamoto,et al.  Suppression of ITI by array head reading and 2D-equalization , 2017 .

[13]  Y. Nakamura,et al.  Read/Write Channel Modeling and Two-Dimensional Neural Network Equalization for Two-Dimensional Magnetic Recording , 2011, IEEE Transactions on Magnetics.

[14]  A. Kavcic,et al.  The Feasibility of Magnetic Recording at 10 Terabits Per Square Inch on Conventional Media , 2009, IEEE Transactions on Magnetics.