Warisarn, Chanon

Loading...
Thumbnail Image
Preferred name
Warisarn, Chanon
Alternative Name
Warisarn, C.
Main Affiliation
Email
chanon.wa@kmitl.ac.th

Settings

Now showing 1 - 5 of 5
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Multilayer Perceptron-Based Soft-Information Modification Technique for Double-Layer Bit-Patterned Magnetic Recording Systems
    (2024-01-01)
    Sawangarom, Visawa
    ;
    Kankhunthod, Kittipon
    ;
    Warisarn, Chanon
    The growing demand for data storage necessitates continuous improvements in hard disk drive (HDD) technologies. Double-layer magnetic recording (DLMR) and bit-patterned magnetic recording (BPMR) technologies are pivotal in enhancing areal density (AD), but they also introduce challenges such as inter-layer interference (ILl) and two-dimensional (2D) inter-ference. This study addresses these challenges by integrating a multilayer perceptron (MLP)-based soft-information modifier into the double-layer BPMR system. The proposed method optimizes the log-likelihood ratio sequence for the recorded tracks on the second recording layer, which are more prone to interference compared with the first recording layer. Our simulations demonstrate significant improvements in bit-error-rate performance across varying levels of media noise and track misregistration. The results also indicate that the MLP-based approach effectively mitigates the adverse effects of interference, thereby enhancing the reliability of data retrieval in high-AD HDD systems.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Optimal Array-Reader and Track Misregistration Mitigation Method in a Three-Reader/Four-Track Reading Bit-Patterned Magnetic Recording System
    (2020-01-01)
    Kankhunthod, Kittipon
    ;
    Buajong, Chaiwat
    ;
    Warisarn, Chanon
    Track misregistration (TMR) is one of several problems in ultrahigh areal density bit-patterned magnetic recording (BPMR) systems, in which the distances between bit-islands are very narrow in both cross-track and down-track directions.Unfortunately,distance reduction leads to intersymbol interference and intertrack interference (ITI) effects,which cause system performance degradation. To deal with these effects, we develop the optimal position of an array-reader based on a three-reader/four-track reading BPMR system that is combined with a simple two-dimensional rate-3/4 modulation code and ITI subtraction technique,which delivers the best avoidance of the ITI effect from sidetracks.We model TMR estimation and mitigation methods using readback signals that are obtained from the optimal array-readers to improve bit error rate (BER) performance.The variance-ratio of these readback signals is used to estimating the TMR levels,whereas a pair of the target’s and equalizer’s coefficients,accordingly designed to the estimated TMR levels,is adopted for mitigating the TMR effect. Simulation results show that our methods provide a high TMR estimation accuracy and gain a superior BER performance compared with the recording system without these techniques under the same user density.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Enhancing Signal Processing With Multilayer Perceptron Utilization for Bit-Patterned Magnetic Recording
    (2025-01-01)
    Rueangnetr, Natthakan
    ;
    Greaves, Simon John
    ;
    Warisarn, Chanon
    Bit-patterned magnetic recording aims to overcome the superparamagnetic limit and achieve higher areal density in magnetic recording, with improved thermal stability and reduced transition noise. However, the inter-symbol interference and inter-track interference effects remain crucial problems that must be addressed. This work introduces a multilayer perceptron-based equalizer operating in conjunction with an adaptive target scheme. Furthermore, we also propose using a multilayer perceptron-based detector to improve the overall recording performance. We evaluated our enhanced processing methods using regular and staggered bit-island arrangements. The simulation results indicate that the multilayer perceptron-based equalizer achieves lower mean square error values across all signal-to-noise ratio levels when compared to the conventional minimum mean square error equalizer. Additionally, the proposed multilayer perceptron-based detector performs slightly better than the multilayer perceptron-based equalizer. Also, these proposed techniques demonstrate superior bit error rate performance, even when considering bit-island position fluctuations.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Modified Multitrack Joint Two-Dimensional Viterbi Detectors for Rate-4/5 and Rate-5/6 Modulation Codes in Bit-Patterned Magnetic Recording Systems
    (2020-01-01)
    Buajong, Chaiwat
    ;
    Warisarn, Chanon
    For an ultrahigh areal-density bit-patterned magnetic recording, system performance is severely degraded by intertrack interference (ITI). Rate-4/5 and rate-5/6 modulation codes were introduced to avoid data patterns that can cause severe ITI. However, their decoders might not be able to correctly perform for data patterns that do not match with their look-up tables during the decoding process. To further improve system performance, we use a multitrack joint two-dimensional (2-D) Viterbi detector for the recommended systems. We also use a modified trellis structure with lower complexity when compared to a conventional joint 2-D detector, which is designed based on their encoding conditions. Simulation results show that our systems outperform the conventional system, especially when they are investigated in a media-noise environment.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    A Multilayer-Perceptron based Method for Track Misregistration Mitigation in Dual-reader/Two-track Reading BPMR Systems
    (2022-01-01)
    Kankhunthod, Kittipon
    ;
    Lee, Jaejin
    ;
    Warisarn, Chanon
    Bit-patterned magnetic recording (BPMR) is the future hard disk drive technology that is expected to gain an areal density of over 4.0 Terabit-per-square-inch (Tbits/in2). However, one of the serious problems is track misregistration (TMR), which easily degrade the overall system's performance. To ensure that the system's performance is acceptable; therefore, we present the TMR mitigation method on a dual-reader/two-track reading (DRTR) BPMR system using an artificial neural network (ANN) model and deep learning technique. To estimate TMR levels, the equalized readback signals are directly fed into a proposed TMR estimator that is performed based on a multilayer perceptron (MLP). In the TMR correction process, both the estimated TMR and equalized readback signals are fed to the MLP detector to detect recorded data bits. The simulation results reveal that the utilization of our proposed TMR mitigation method can improve the bit-error-rate performance of the BPMR system when they were compared with the system that uses another mitigation method.