Proactive Channel Adjustment to Improve Polar Code Capability for Flash Storage Devices

• Main Authors: Kun-Cheng Hsu, 徐堃程
• Other Authors: 郭大維
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/69719277341392564293

碩士 === 國立臺灣大學 === 資訊工程學研究所 === 105 === Low-density parity-check (LDPC) codes have made a great success on correcting errors in flash storage devices, but its hardware cost and error correction time keeps increasing as the error rate of flash memory keeps increasing. To improve the lifetime of devices, researchers are seeking alternative methods. Fortunately, with the low encoding/ decoding complexity and the high error correction capability, polar code with the support of list-decoding and cyclic redundancy check can outperform LDPC code in the area of data communication. Thus, it also draws a lot of attentions on how to adopt and enable polar codes in storage applications. However, the code construction and encoding length limitation issues obstruct the adoption of polar codes in flash storage devices. To enable polar codes in flash storage devices, we propose a proactive channel adjustment design to extend the effective time of a code construction to improve the error correction capability of polar codes. This design pro-actively tunes the quality of the desirable flash cells to maintain the correctness of the code construction and relax the constraint of encoding length limitation. A series of experiments was conducted to evaluate the efficacy of the proposed design. It shows that the proposed design can effectively improve the error correction capability of polar codes in flash storage devices.