Suppression of ITI by array head reading and 2D-equalization

Y Nakamura,H Muraoka,Y Kanai,H Osawa,Y Okamoto,R Suzuto

doi:10.1063/1.4977548

Y Nakamura, H Muraoka + Show 4 more

Open Access

https://doi.org/10.1063/1.4977548

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Abstract

Two-dimensional magnetic recording (TDMR) by shingled magnetic recording (SMR) draws attention as a next generation technology to increase the recording density in hard disk drive (HDD). It is shown that the two-dimensional finite impulse response (2D-FIR) filter provides gain the reproducing waveforms from an array head with 3 readers in the TDMR under a specification of 4 Tbit/inch.2 We evaluate the effect of the intertrack interference (ITI) reduction by 2D-FIR using the correlation between the real FIR filter output and the partial response class-I (PR1) signal corresponding to recording sequence by the computer simulation. The results show that the 2D-FIR filter is effective to mitigate ITI and improves the signal-to-noise ratio at the discriminate point by about 0.6 dB.

Highlights

Two dimensional magnetic recording (TDMR) using shingled magnetic recording (SMR)[1] is one of the most promising technologies for realizing ultra-high areal recording densities
We study for suppression on intertrack interference (ITI) by the array head reading and two-dimensional (2D) equalization on the TDMR under a specification of 4 Tbit/inch.[2]
The results show that the 2D-FIR filter is effective to mitigate ITI, and improves the SNRD about 0.6 dB

Summary

INTRODUCTION

Two dimensional magnetic recording (TDMR) using shingled magnetic recording (SMR)[1] is one of the most promising technologies for realizing ultra-high areal recording densities. We assume discretized granular medium with non-magnetic grain boundaries based on a discrete Voronoi model.[4] Figure 1 shows an example of the model. A channel bit response for head and medium of Track #l is equalized by the LPF with cut-off frequency xh normalized by f c and the 2D-FIR filter with Nt taps[8] to partial response (PR) class-I (PR1) target.[9] The PR channel controls the amount of ISI so as not to degrade SNR at the channel output for the maximum-likelihood detection.[10] In this study, the interference cancellation is expanded to that from the adjacent tracks, ITI, by introducing the 2D-FIR filter.

SUPPRESSION OF ITI BY ARRAY HEAD READING AND 2D-EQUALIZER

CONCLUSION