Prospects for Magnetic Recording over the next 10 years

Wood, Roger; Takano, Hirotaka

doi:10.1109/intmag.2006.375598

Cited by 31 publications

(10 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SNR is fixed at 13 dB. The 3 × 3 2D-ISI mask h is computed from (2). Each curve corresponds to a fixed GPB.…”

Section: Simulation Resultsmentioning

confidence: 99%

“…Two-dimensional magnetic recording (TDMR) [1] is a newly proposed technology that utilizes specialized read and write-head designs together with novel signal processing and coding techniques to increase the storage density on conventional magnetic hard disks. TDMR is likely to be available relatively more quickly than alternative emerging technologies such as heat-assisted-magnetic-recording (HAMR) [2] and bit patterned media recording (BPM) [3], which require the recording medium to be radically redesigned [1].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

EXIT chart based IRA code design for TDMR

Mehrnoush

Belzer

Sivakumar

et al. 2016

2016 Annual Conference on Information Science and Systems (CISS)

View full text Add to dashboard Cite

This paper presents an extrinsic information transfer (EXIT) chart based irregular repeat-accumulate (IRA) code design technique for a two-dimensional magnetic recording (TDMR) turbo-equalizer that employs a Voronoi magnetic grain model. The channel model also includes two-dimensional intersymbol interference (2D-ISI) and additive white Gaussian noise (AWGN). At high bit densities (e.g., between 1 and 3 magnetic grains per coded bit (GPB)), occasionally a bit will not be written on any grain, and hence will effectively be "overwritten" (or erased) by bits on surrounding grains. The proposed code design takes into account the statistics of the TDMR channel to decrease overwrite effects. The proposed receiver uses a 2D-ISI BCJR equalizer and IRA decoder in a turbo-equalization approach. To design the IRA code, we find the experimental EXIT chart curves of the check node decoder (CND) and the combination of the variable node decoder (VND) with the 2D-ISI equalizer. We fit the VND and CND EXIT chart curves to find the IRA code's optimized variable node degree distribution for the TDMR channel. Simulation results show that the IRA codes optimized for the TDMR Voronoi grain model achieve up to a 3.3% density increase in user-bits/grain (U/G) compared to IRA codes designed for AWGN channels. At 1.2 GPB, the designed IRA codes achieve densities as high as 0.455 U/G, corresponding to an areal density of about 4.6 Terabits/in 2 on typical magnetic hard disks with 10 Teragrains/in 2 ; this is nearly a factor of 5 better than the best commercially available systems.

show abstract

“…The SNR is fixed at 13 dB. The 3 × 3 2D-ISI mask h is computed from (2). Each curve corresponds to a fixed GPB.…”

Section: Simulation Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

EXIT chart based IRA code design for TDMR

Mehrnoush

Belzer

Sivakumar

et al. 2016

2016 Annual Conference on Information Science and Systems (CISS)

View full text Add to dashboard Cite

show abstract

“…In hard disk drives (HDDs) technology, the last decade has seen the rapid growth rate of 100% per year in the recording density [1]. The effort is still continuing to push the recording density to beyond 1Tb/in 2 .…”

Section: Introductionmentioning

confidence: 99%

Adaptive disturbance rejection in the presence of uncertain resonance mode in hard disk drives

Fan

Tee

et al. 2009

Transactions of the Institute of Measurement and Control

View full text Add to dashboard Cite

Abstract-An adaptive on-line scheme is designed to identify the uncertain and time-varying resonance modes in hard disk drive servo systems. Based on the identified results, the uncertain resonance mode is extracted and a peak filter is designed accordingly to provide stronger capability of disturbance suppression. The scheme does not require any extra excitation signal nor additional signal processing for the parameter identification. Compared to conventional method, the rates of learning and error convergence are greatly increased. The scheme can provide good stability margin at high frequency subject to the variation of the resonance frequency and the peak gain. Simulation results show the validity and effectiveness of the proposed scheme.

show abstract

“…The most significant trend in the hard disk drive (HDD) industry is the rapid increase of track density and storage capacity, as well as faster accessing time and wider applications in consuming electronics [1]. It would require HDD servo systems to have more precise and faster positioning as well as better disturbance rejection capability without sacrifice of system robustness.…”

Section: Introductionmentioning

confidence: 99%

Modeling of nonlinear dynamics at low frequencies in hard disk drive and its adaptive compensation

Zhang

Fan

et al. 2009

2009 IEEE International Conference on Control and Automation

View full text Add to dashboard Cite

In hard disk drive servo system, the rejection of disturbances at low frequencies is degraded due to the nonlinearities of pivot friction and flex-cable bias. In this paper, a novel parametrized dynamic model is proposed with the parameters being functions of position. The proposed model provides good matching in both time domain and frequency domain. Based on this nonlinear parametrized model, a feedforward controller with adaptive gain is designed and implemented. The simulation and experimental results show that the proposed method can improve the servo performance effectively.

show abstract

Prospects for Magnetic Recording over the next 10 years

Cited by 31 publications

References 3 publications

EXIT chart based IRA code design for TDMR

EXIT chart based IRA code design for TDMR

Adaptive disturbance rejection in the presence of uncertain resonance mode in hard disk drives

Modeling of nonlinear dynamics at low frequencies in hard disk drive and its adaptive compensation

Contact Info

Product

Resources

About