Journal of the Institute of Electronics Engineers of Korea TC (대한전자공학회논문지TC)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Improvement of the Sphere Decoding Complexity through an Adaptive OSIC-SD System

Adaptive OSIC-SD 시스템을 통한 SD 복호기 복잡도 개선

  • Portugal, Sherlie (Department of Electronics Engineering, Chonnam National University) ;
  • Yoon, Gil-Sang (Department of Electronics Engineering, Chonnam National University) ;
  • Seo, Chang-Woo (Department of Electronics Engineering, Chonnam National University) ;
  • Hwang, In-Tae (Department of Electronics Engineering, Chonnam National University)
  • Received : 2010.08.18
  • Accepted : 2011.03.17
  • Published : 2011.03.25
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Abstract

Sphere Decoding (SD) is a decoding technique able to achieve the Maximum Likelihood (ML) performance in fading environments; nevertheless, the main disadvantage of this technique is its high complexity, especially in poor channel conditions. In this paper, we present an adaptive hybrid algorithm which reduces the conventional Sphere Decoder's complexity and keeps the ML performance. The system called Adaptive OSIC-SD modifies its operation based on Signal to Noise Ratio (SNR) information and achieves an optimal performance in terms of Bit Error Rate (BER) and complexity. Through simulations, we probe that the proposed system maintains almost the same bit error rate performance of the conventional SD, and exhibits a lower, quasi-constant complexity.

SD(Sphere Decoding)는 페이딩 환경에서 ML(Maximum Likelihood)성능을 만족하지만 채널환경이 나빠질수록 매우 복잡도가 증가하는 단점이 있다. 본 논문에서는 이러한 특징을 같은 기존 SD를 개선하고자 기존의 ML성능을 유지 시키면서 복잡도를 줄이기 위한 방안으로 부분적으로 OSIC(Ordered Successive Interference Cancellation)를 결합하는 시스템을 제안하다. 또한, SNR(신호 대 잡음비: Signal to Noise Ratio)에 따라서 복잡도 및 비트오류율(BER : Bit Error Rate)의 성능이 최적으로 동작하는 복호기를 적응적으로 사용 Adaptive OSIC-SD 알고리즘 제안한다. 모의실험 결과, 제안된 시스템의 비트오류율은 기존의 SD와 거의 비슷한 성능을 보이면서, 일정하고 더 낮은 복잡도를 보이는 것을 확인할 수 있었다.

Keywords

References

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