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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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A Recursive ICI Cancellation Technique for Cooperative STBC-OFDM Systems with Carrier Frequency Offsets

반송파 주파수 옵셋을 갖는 상호협력 STBC-OFDM 시스템을 위한 반복적 ICI 제거 기법

  • 김영준 (중앙대학교 전자전기공학부 디지털통신연구실) ;
  • 우경수 (중앙대학교 전자전기공학부 디지털통신연구실) ;
  • 유현일 (중앙대학교 전자전기공학부 디지털통신연구실) ;
  • 이희수 (한국전자통신연구원) ;
  • 조용수 (중앙대학교 전자전기공학부 디지털통신연구실)
  • Published : 2007.10.31
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Abstract

In this paper, a recursive intercarrier interference (ICI) cancellation technique for cooperative space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) with different carrier frequency offsets (CFOs) is proposed. Also, different CFOs existing in a cooperative STBC-OFDM system is shown to produce phase difference in the received signal, causing noise enhancement effect in the STBC decoding process. The performance degradation caused by the noise enhancement effect can be effectively reduced by a proposed ML-based recursive ICI cancellation technique. It is shown by computer simulation that the proposed recursive ICI cancellation technique is effective in reducing ICI, especially for STBC-OFDM systems with a large FFT size and large CFOs.

본 논문에서는 상호협력 STBC-OFDM 시스템에서 다른 반송파 주파수 옵셋(CFO) 존재시 이를 극복할 수 있는 반복적 반송파간 간섭(ICI) 제거 기법을 제안한다. 상호협력 STBC-OFDM 시스템에서 존재하는 다른 CFO는 수신 신호에서 위상차를 발생하여 STBC 복호 과정에서 잡음 증가 현상을 가져온다. 이러한 잡음 증가 효과에 따른 성능 감소는 본 논문에서 제안된 ML 기반의 반복적 ICI 제거 기법을 사용하여 효과적으로 감소시킬 수 있음을 보인다. 모의실험을 통하여 제안된 반복적 ICI 제거 기법이 특히 FFT 크기가 크고 CFO 값이 큰 STBC-OFDM 시스템에서 ICI의 영향을 감소하는데 효과적으로 사용될 수 있음을 확인한다.

Keywords

References

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