한국통신학회논문지 (The Journal of Korean Institute of Communications and Information Sciences)

  • 제38C권6호
  • /
  • Pages.540-549
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  • 2013
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  • 1226-4717(pISSN)
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  • 2287-3880(eISSN)
한국통신학회 (The Korean Institute of Commucations and Information Sciences)
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멀티 레벨 셀 낸드 플래시 메모리용 적응적 양자화기 설계

Adaptive Quantization Scheme for Multi-Level Cell NAND Flash Memory

  • 이동환 (서울대학교 전기 정보 공학부 멀티미디어 시스템 연구실) ;
  • 성원용 (서울대학교 전기 정보 공학부 멀티미디어 시스템 연구실)
  • 투고 : 2013.04.01
  • 심사 : 2013.06.05
  • 발행 : 2013.06.30
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초록

본 논문에서는 멀티 레벨 셀 낸드 플래시 메모리에서 연판정 에러 정정을 위한 적응적 비균일 양자화기를 제안한다. 기존의 최대 상호 정보(maximum mutual information) 양자화기는 최적의 연판정 에러 정정 성능을 보이지만, 소모적인 탐색(exhaustive search)으로 인하여 많은 계산량을 요구한다. 본 논문에서 제안된 양자화기는 최대 여섯 개의 파라미터로 표현되는 간단한 구조를 갖고 있어 연산량이 적다. 또한 제안된 양자화기는 쓰기 심볼과 읽기 심볼 사이의 상호 정보를 최대화하는 방향으로 파라미터 값의 최적화시키므로, 최대 상호 정보 양자화기에 근접하는 우수한 연판정 에러 정정 성능을 보인다.

An adaptive non-uniform quantization scheme is proposed for soft-decision error correction in NAND flash memory. Even though the conventional maximizing mutual information (MMI) quantizer shows the optimal post-FEC (forward error correction) bit error rate (BER) performance, this quantization scheme demands heavy computational overheads due to the exhaustive search to find the optimal parameter values. The proposed quantization scheme has a simple structure that is constructed by only six parameters, and the optimal values of them are found by maximizing the mutual information between the input and the output symbols. It is demonstrated that the proposed quantization scheme improves the BER performance of soft-decision decoding with only small computational overheads.

키워드

참고문헌

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