Rate-4/5 4-ary modulation code for 4-level holographic data storage systems

Abstract

This paper presents a 4/5 4-ary modulation code design for 4-level holographic data storage (HDS) systems. The multi-level HDS systems, capable of far greater storage densities than traditional storage technologies, are regarded as one of the most promising candidates for ultra-high-capacity optical storage devices. Significantly, the HDS systems promises to provide the best solutions for cloud storage services. Yet, the systems are significantly disturbed by many challenges, such as two-dimensional (2D) interference, blur effect, and misalignment. The proposed code is designed based on a 4-step procedure, where the codewords at the output of the encoder can avoid not only the effect of the worst 2D interference but also obtain a minimum distance between two arbitrary codewords of 0.47, which is larger than the minimum distance of a conventional 6/9 modulation code. Simulation results demonstrate that the proposal gains about 1 dB better than the traditional 6/9 modulation code at a ${10}^{-9}$ bit error rate.

Keywords:

• Holographic data storage systems
• multi-level code
• two-dimensional interference
• modulation codes

Acknowledgments

This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 102.04-2019.307.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

The work was supported by the National Foundation for Science and Technology Development [102.04-2019.307]

Notes on contributors

Chi Dinh Nguyen

Chi Dinh Nguyen received the B.Eng. degree in Electrical and Electronic Engineering from the Le Quy Don Technical University, Hanoi, Vietnam, in 2012, and the M.Eng. and Ph.D. degrees in Information Telecommunication Engineering from Soongsil University, Seoul, South Korea, in 2015 and 2017, respectively. From 2017 to 2019, he was a Postdoctoral Research Fellow at the Singapore University of Technology and Design. From 2019 to 2021 he was a Lecturer/Researcher with the Phenikaa University. Currently he is a Director of IT Program with the FPT University, Hanoi, Vietnam. He was the first and major author of one best paper and two outstanding papers from the 2020 International Conference on Advanced Technologies for Communications and the Asia-Pacific Magnetic Recording Conference in 2016 and 2018. He is also the major inventor of four patents issued by South Korea so far. His main research interests include signal processing and coding for information storage systems, applying learning algorithms to channel detection and decoding, and digital transmission engineering for telecommunication systems.