A Study of TDMR Signal Processing Opportunities Based on Quasi-Micromagnetic Simulations

Vasić, Bane; Khatami, Mehrdad; Nakamura, Yūichi; Okamoto, Yoshihiro; Kanai, Y.; Barry, John R.; McLaughlin, S.W.; Sadeghian, Elnaz Banan

doi:10.1109/tmag.2014.2356455

Cited by 15 publications

(2 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most harmful input patterns are the ones with consecutive transitions in both cross-track and down-track directions. We have also observed the same characteristics of media noise studied with a more realistic channel model in [12]. In the sequel, we introduce three definitions of SNR corresponding to overall noise, media noise and the electronic noise in TDMR systems.…”

Section: Noise Characteristics Of the Tdmr Systemsmentioning

confidence: 53%

Investigation Into Harmful Patterns Over Multitrack Shingled Magnetic Detection Using the Voronoi Model

et al. 2015

Self Cite

View full text Add to dashboard Cite

Two Dimensional Magnetic Recording (TDMR) is a promising technology for next generation magnetic storage systems based on a systems level framework involving sophisticated signal processing at the core. The TDMR channel suffers from severe jitter noise along with electronic noise that needs to be mitigated during signal detection and recovery. Recently, we developed noise prediction based techniques coupled with advanced signal detectors to work with these systems. However, it is important to understand the role of harmful patterns that can be avoided during the encoding process. In this paper, we investigate into the Voronoi based media model to study the harmful patterns over multi-track shingled recording systems. Through realistic quasi micromagnetic simulations studies, we identify 2D data patterns that contribute to high media noise. We look into the generic Voronoi model and present our analysis on multi-track detection with constrained coded data. We show that two dimensional (2D) constraints imposed on input patterns result in an order of magnitude improvement in the bit error rate for TDMR systems. The use of constrained codes can reduce the complexity of 2D intersymbol interference (ISI) signal detection since lesser 2D ISI span can be accommodated at the cost of a nominal code rate loss. However, a system must be designed carefully so that the rate loss incurred by a 2D constraint does not offset the detector performance gain due to more distinguishable readback signals.Index Terms-TDMR systems, 2D no isolated bit constraint, multi-track detection, bit error rate, GBP algorithm.

show abstract

Section: Noise Characteristics Of the Tdmr Systemsmentioning

confidence: 53%

Investigation Into Harmful Patterns Over Multitrack Shingled Magnetic Detection Using the Voronoi Model

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…We simulate the granular medium with non-magnetic grain boundaries based on a discrete Voronoi diagram [8], [9], [10]. The average grain size and the standard deviation of grain size normalized by the average grain size are 5.0 nm and 0.2, respectively.…”

Section: Read/write Channel Modelmentioning

confidence: 99%

Effect of Reader Sensitivity Rotation in TDMR With Head Skew

et al. 2016

View full text Add to dashboard Cite

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.

show abstract

Shingled Magnetic Recording (SMR) and Two-Dimensional Magnetic Recording (TDMR)

Wood

2022

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

A Study of TDMR Signal Processing Opportunities Based on Quasi-Micromagnetic Simulations

Cited by 15 publications

References 20 publications

Investigation Into Harmful Patterns Over Multitrack Shingled Magnetic Detection Using the Voronoi Model

Investigation Into Harmful Patterns Over Multitrack Shingled Magnetic Detection Using the Voronoi Model

Effect of Reader Sensitivity Rotation in TDMR With Head Skew

Shingled Magnetic Recording (SMR) and Two-Dimensional Magnetic Recording (TDMR)

Contact Info

Product

Resources

About