Construction of Spatially Coupled GC-LDPC Code for NAND Flash Memory

With the continuous improvement of data memory density, as the common solution for error correction of NAND flash, the low-density-parity-check (LDPC) code faces more challenges, such as the increasing code length requirements, the worse raw bit error rates (RBER), and the frequently varied channels. In this paper, a new (37536, 33672) spatially coupled and globally coupled LDPC (SC-GC-LDPC) code is constructed to address the above challenge, which outperforms the traditional globally coupled LDPC (GC-LDPC) code with the gaps of 0.065 dB and 0.08 dB by exploiting the layered sumproduct algorithm (SPA) and the layered normalized min-sum (NMS) algorithm, respectively. Moreover, in the flash channel, the SC-GC-LDPC code also shows superior error correction performance as compared with the conventional GC-LDPC codes, which can effectively adapt to flash channels in different pages.