Title
A Program Interference Error Aware LDPC Scheme for Improving NAND Flash Decoding Performance.
Abstract
By scaling down to smaller cell size, NAND flash has significantly increased the storage capacity in order to lower the unit cost down. However, the reliability is sacrificed due to much higher raw bit error rates. As a result, conventional error correction codes (ECCs), such as BCH codes, are not sufficient. Low-density parity check (LDPC) codes with stronger error correction capability are adopted in NAND flash to guarantee data reliability. However, read performance using LDPC is poor because of its decoding complexity. It has been found that flash cells with fewer electrons are more prone to program interference errors. As a result, program interference errors show the characteristic of value dependence. This characteristic can be exploited and translated into extra information facilitating the decoding convergence. Motivated by this observation, we propose PEAL: a flash <underline>p</underline>rogram interference <underline>e</underline>rror <underline>a</underline>ware <underline>L</underline>DPC scheme to enhance the decoding performance. PEAL integrates the obtained extra information from the value dependence into the soft-to-hard decision process in LDPC decoding to decrease decoding iterations and improve the decoding convergence speed. Simulation results show that decoding iterations are reduced by up to 69.37% and the decoding convergence speed is improved by up to 2.5×, compared with the normalized min-sum (NMS) algorithm with 2KB information lengths at an approximate raw bit error rate of 11.5 × 10−3.
Year
DOI
Venue
2017
10.1145/3126563
ACM Trans. Embedded Comput. Syst.
Keywords
Field
DocType
LDPC codes, Program interference error, value dependence
Parity bit,Sequential decoding,Low-density parity-check code,Computer science,BCH code,NAND gate,Real-time computing,Error detection and correction,Decoding methods,List decoding
Journal
Volume
Issue
ISSN
16
5
1539-9087
Citations 
PageRank 
References 
0
0.34
25
Authors
7
Name
Order
Citations
PageRank
Fei Wu110435.76
Meng Zhang2165.23
Yajuan Du312.37
Xubin He474763.49
Ping Huang518429.52
Changsheng Xie6329.93
Jiguang Wan74710.21