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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Link Adaptation with SNR Offset for Wireless LAN Systems

무선 LAN 시스템에서의 SNR 오프셋을 이용한 링크 적응화

  • 김찬홍 (서울대학교 전기.컴퓨터공학부 무선신호처리연구실) ;
  • 정교원 ;
  • 고경준 (서울대학교 전기.컴퓨터공학부 무선신호처리연구실) ;
  • 이정우 (서울대학교 전기.컴퓨터공학부 무선신호처리연구실)
  • Received : 2011.06.20
  • Accepted : 2011.10.16
  • Published : 2011.10.31
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Abstract

Link Adaptation should select the best modulation and coding scheme (MCS) which gives the highest throughput as channel conditions vary. Several link adaptation algorithms for wireless local area network (WLAN) have been proposed but for the future WLAN systems such as 802.11n system, these algorithms do not guarantee the best performance. In this paper, we propose a new link adaptation algorithm in which an MCS level is chosen by the received SNR plus the offset value obtained from the transmission results. The performance of proposed algorithm is simulated by an IEEE 802.11n system. From the analysis, we conclude the proposed algorithm performs better than the well-known link adaptation algorithms such as auto rate fallback and general SNR-based techniques. Particularly, the proposed algorithm improves throughput when the packet error ratio (PER) is constrained for fast fading channels.

링크 적응 기법은 변하는 채널 조건에 맞는 최적의 MCS 레벨을 선택한다. 무선 LAN 시스템을 위한 다양한 링크 적응 알고리즘이 제안되었으나 802.11n과 같은 최근의 시스템에서 최적의 성능을 보장하지는 않는다. 본 논문에서는 수신 SNR과 전송 결과에 따라 얻어지는 오프셋 값을 이용한 새로운 링크 적응 알고리즘을 제안한다. 802.11n 시스템에서 모의실험을 하여 제안된 알고리즘과 잘 알려져 있는 ARF 및 일반적인 SNR기반 알고리즘과 그 성능을 비교해본다. 제안된 알고리즘은 PER에 제한이 있는 경우 시변채널에서 더 좋은 성능을 보인다.

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References

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