Warisarn, Chanon
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Preferred name
Warisarn, Chanon
Alternative Name
Warisarn, C.
Main Affiliation
Email
chanon.wa@kmitl.ac.th
7 results
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Item type:Publication, Reliability Test Techniques in Tabu Search Detection for Enhancing BER Performance of Array Reader Bit-Patterned Magnetic Recording Systems(2026-01-01); ; Bit-patterned magnetic recording (BPMR) at ultra-high densities is strongly affected by inter-track interference (ITI). To cope with severe ITI, we introduce a reliability-testing mechanism with adaptive symmetric thresholding based on the distribution of log-likelihood ratios (LLRs) to effectively identify unreliable bits while controlling the computational complexity of the Tabu search (TS) detector. Additionally, the selected bits identified from the TS detection are employed to refine the original LLR values through a proposed soft-information adjustment (SIA) process. Moreover, we also present an LLR weighting scheme to further enhance the refined LLRs produced by the SIA process, thereby improving the performance of low-density parity-check decoding. Results indicate that our proposed technique can reduce the complexity of the TS detector by using a reliability-testing mechanism. The SIA can be effectively combined with an LLR weighting scheme, thereby improving bit-error rate performance over conventional BPMR systems. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mitigating the Effects of Track Mis-Registration in Single-Reader/Two-Track Reading BPMR Systems(2019-07-01)Bit-recording technologies that can provide areal densities (ADs) [patterned magnetic recording (BPMR) is expected to be one of the new magnetic ADs] of 1 Tera-bit per square inch or higher. To achieve these ADs, the space between tracks must be reduced, bringing them closer and closer together, leading to significant inter-track interference (ITI). Track mis-registration (TMR) or head offset can further degrade overall system performance. To mitigate the effects of ITI and TMR, we propose using a single-reader/two-track reading (SRTR) scheme together with an over-sampling technique on a staggered BPMR system. We also propose a TMR estimation technique based on a readback signal. Here, the readback signal is separated into two sequences, one odd and one even. Then, the energy ratio is calculated using these data sequences. The obtained relationship between the energy ratio and head offset can be utilized to predict the actual head offset occurrence in the reading process. Finally, a pairing of a monic constraint target and an equalizer that accordingly matches each estimated head offset level is adopted to deal with the TMR effect. The SRTR system can provide better bit-error-rate (BER) performance. Moreover, when TMR effects appear in the reading process, our proposed SRTR system with a TMR mitigation technique can yield better BER performance, especially at high head offset levels. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Track Misregistration Mitigation Using CNN-Based Method on Single-Reader/Two-Track Reading BPMR Systems(2023-01-01); One of the problems that cause a decrease in the performance of the ultra-high bit-patterned magnetic recording (BPMR) system is track misregistration (TMR). Since the gap between data tracks is extremely narrow, it easily affects keeping the reader in the desired position. Therefore, this paper proposes the track misregistration mitigation included the estimation and correction techniques on single-reader/two-track reading (SRTR) BPMR using only a readback signal. The TMR estimation technique uses the convolutional neural network (CNN) to estimate the TMR level by the histograms of the readback signal enabling minimization of the complexity of the CNN structure and amount of training time. The estimated TMR levels obtained from the proposed CNN-histogram-based method will then be utilized to detect the estimated recorded bit by the CNN-based data detector. The simulation shows that our proposed system provides better TMR prediction accuracy even though the system has to face higher media noise. Furthermore, the CNN-based data detectors perform superior to the partial response maximum likelihood (PRML) based data detector, especially in strong electronic noise situations and the severe imperfection of recording media. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Three-Track Detection Using a Multilayer Perceptron for Dual-Layer Bit-Patterned Magnetic Recording Systems(2026-01-01); Kilaso, SathapathThis article proposes a multilayer perceptron (MLP)-based three-track detection method for dual-layer bit-patterned magnetic recording (BPMR) systems. Three different MLP architectures are explored and evaluated, namely: 1) a single MLP detecting all three tracks simultaneously; 2) three MLPs, each detecting one track independently; and 3) two MLPs dedicated to upper and lower recording layers. Simulation results show that the proposed MLP-based systems outperform the conventional partial-response maximum-likelihood (PRML) detection scheme, particularly under severe interferences and high areal density (AD). Among the proposed systems, the two-MLP architecture offers the optimal balance between detection accuracy and computational complexity, making it the most promising solution for future high-density magnetic recording systems. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Modified 2D Viterbi Algorithm using 2D Modulation Encoding Constraints in BPMR Systems(2020-06-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, An Iterative Two-Head Two-Track Detection Method for Staggered Bit-Patterned Magnetic Recording Systems(2019-07-01); Kovintavewat, PiyaOne of the major problems in bit-patterned magnetic recording (BPMR) systems is an inter-track interference (ITI) that can significantly degenerate the system performance, especially at high areal densities (ADs). Generally, the BPMR system with staggered islands experiences less ITI effect than that with regular islands. Therefore, we propose an iterative two-head two-track detection method for a staggered BPMR system to further reduce the ITI effect, which employs two read heads to read two adjacent tracks and decodes them simultaneously. To lessen the ITI, the weighted readback signal of one track, serving as an ITI signal, is subtracted from the readback signal of the other track, and vice versa, before passing the refined readback signal to an iterative decoding process. Hence, the decoded data will be utilized to estimate the ITI signal for the next global iteration, NG. Supposing that the refined readback signal has only one-side ITI effect. We also present the design of the 2× 3 target and its compatible equalizer that will be employed in the proposed system. Results demonstrate that the proposed system not only is superior to the conventional system but also has low complexity. Specifically, the proposed system can perform close to the conventional system whose readback signal encounters only one-side ITI effect when NG = 2, 3 and 5 iterations for AD = 2, 2.5, and 3 Tb/in<sup>2</sup>, respectively. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Soft-Information Improvement using Multilayer Perceptron (MLP) in Bit-Patterned Magnetic Recording (BPMR) Systems(2021-06-27);