Open AccessImproving the data reliability of phase modulated holographic storage using a reliable bit aware low-density parity-check code
Author(s) -
Yahui Zhao,
Fei Wu,
Xiao Lin,
Jing Zhou,
Meng Zhang,
Qin Yu,
Xiaodi Tan,
Conghua Xie
Publication year - 2022
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.464537
Subject(s) - low density parity check code , computer science , holographic data storage , decoding methods , demodulation , bit error rate , parity bit , error detection and correction , algorithm , reliability (semiconductor) , computer data storage , computer hardware , physics , telecommunications , channel (broadcasting) , power (physics) , quantum mechanics
Phase modulated holographic storage offers superior storage capacity and a longer life span compared with other storage technologies. However, its application is limited by its high raw bit error rate. We aimed to introduce low-density parity-check (LDPC) codes for data protection in phase modulated holographic storage systems. However, traditional LDPC codes can not fully exploit data error characteristics, causing inaccurate initial log-likelihood ratio (LLR) information, which degrades decoding performance, thus limiting the improvement degree of data reliability in phase modulated holographic storage. Therefore, we propose a reliable bit aware LDPC optimization method (RaLDPC) that analyzes and employs phase demodulation characteristics to obtain reliable bits. More accurate initial LLR weights are assigned to these reliable bits. Hence, the optimized initial LLR can reflect the reliability of the demodulated data more accurately. Experimental results show that RaLDPC can reduce the bit error rate by an average of 38.89% compared with the traditional LDPC code, improving the data reliability of phase modulated holographic storage.