Dynamic LLR scheme based on EM algorithm for LDPC decoding in NAND flash memory

IEICE Electronics Express

Qi Wang¹  Xiang Fu¹  Zongliang Huo²  Junli Peng³ 

[1] Institute of Microelectronics of Chinese Academy of Sciences;School of Microelectronics, University of Chinese Academy of Sciences;University of Chinese Academy of Sciences

关键词: NAND flash memory;    threshold voltage distribution;    EM algorithm;    LDPC code;    soft information;   

DOI  :  10.1587/elex.14.20170820

学科分类：电子、光学、磁材料

来源: Denshi Jouhou Tsuushin Gakkai

【 摘 要 】

A dynamic log-likelihood ratio (DLLR) scheme based on expectation-maximization (EM) algorithm for the decoding of low-density parity-check (LDPC) codes in NAND flash memory is proposed. When LDPC soft decoding fails, the DLLR scheme employs the EM algorithm to estimate the parameters of the threshold voltage distribution of NAND flash memory, and then recalculates the LLR values for decoding. Simulation results show that the proposed scheme can significantly improve the error correcting performance of LDPC soft decoding in NAND flash memory.

【 授权许可】

CC BY