面向闪速存储系统的编译码技术研究

项目名称： 面向闪速存储系统的编译码技术研究

项目编号： No.61271004

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 慕建君

作者单位： 西安电子科技大学

项目金额： 55万元

中文摘要： 多级存储单元(MLC)技术可用来提高NAND闪存的数据存储密度(容量)，然而，随着NAND闪存芯片封装尺寸的缩小，MLC型NAND闪存的可靠性面临着严峻的挑战，无法满足未来数据存储系统的需求。本项目拟研究闪存系统的差错控制编码和译码理论及方法，设计可纠 "大量电荷突发泄漏"和"强度有限"等闪存错误的纠错码编译码方案。具体内容包括：理论分析和确定有效的交织置换策略，设计纠"大量电荷突发泄漏错误"的等级调制纠错码编码方案；基于置换群论，探索良好距离特性子群码的有效选择方法，设计强度有限错误的等级调制纠错码有效构造方法；建立等级调制纠错码的LP译码模型，设计纠这两种闪存错误的相应纠错码LP译码算法；基于读信道互信息优化方法，研究LDPC码译码器对数似然比信息的有效计算方法，设计MLC型闪存LDPC码的低复杂度软判决译码算法。通过本项目的研究，期望能够为未来存储系统提供高效实用的差错控制编码方案。

中文关键词： 闪速存储器；等级调制；编译码方案；软判决译码；线性规划译码

英文摘要： Multi-Level Cell (MLC) technique can be used to increase the data storage density/capacity of NAND flash memories. However, as the size of CMOS chip package scales down, flash memory also faces severe reliability challenges and cannot meet the demands for future storage systems. The objectives of this project are to investigate the error-control coding and decoding theories for flash memory storage systems, and design encoding and decoding schemes of codes for the rank modulation scheme which protect against transposition errors, which are brought by sudden and steep drops in the charge of one group of flash memory cells, and limited-magnitude errors. The contents of this project are summarized as follows: (1) By making a theoretical analysis of efficient strategies of interleaving permutations, we design the encoding schemes of the error-control codes based on rank modulation for transposition errors which are brought by sudden and steep drops in the charge of one group of flash memory cells. (2) Based on permutation group theory, some efficient selection methods of subgroup codes are explored in order to design construction methods of codes for the rank modulation scheme which protect against limited-magnitude errors. (3) By building LP decoding models of the error-control codes for rank modulation, we desi

英文关键词： Flash memory；rank modulation；coding and decoding scheme；soft-decision decoding；linear programming (LP) decoding