基于加权比特翻转的MLC型NAND闪存系统

Research on MLC NAND Flash Memory Based on Weighted Bit-flipping Decoding Algorithm

摘要: 多级单元(Multi-Level-Cell, MLC)技术增加了NAND闪存的存储密度, 但也增强了单元间干扰(Cell-to-Cell Interference, CCI)噪声强度, 导致了NAND闪存的可靠性急剧下降.在深入研究MLC闪存模型和CCI噪声模型基础上, 提出了一种MLC型NAND闪存的加权比特翻转硬判决译码方法.仿真结果表明, 在MLC闪存信道条件下, 该方法既可保证MLC闪存单元的可靠性, 对可保持较低的译码复杂度, 从而实现了译码复杂度和性能间的良好折衷.

Abstract: Multi-level cell(MLC) increases the storage density of NAND flash memory, while the Cell-to-Cell interference (CCI) is enhanced, and the reliability of NAND flash memory is decreased. On the research of MLC channel model and CCI noise model, this paper proposes a weighted bit-flipping decoding algorithm for MLC NAND flash memory. The simulation results show that this method can ensure the reliability of the NAND flash memory, while maintaining low decoding complexity, so as to realize a better tradeoff between complexity and decoding performance.