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

  • 제35권8A호
  • /
  • Pages.768-776
  • /
  • 2010
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  • 1226-4717(pISSN)
  • /
  • 2287-3880(eISSN)
한국통신학회 (The Korean Institute of Commucations and Information Sciences)
권호 표지

다중 안테나를 사용하는 인지무선 시스템에서 가중치 precoder를 통한 간섭 제거 기법

The Interference Nulling using Weighted Precoding in the MIMO Cognitive Radio System

  • 이선영 (인하대학교 정보통신대학원 무선전송연구실) ;
  • 손성환 (인하대학교 정보통신대학원 무선전송연구실) ;
  • 장성진 (인하대학교 정보통신대학원 무선전송연구실) ;
  • 김재명 (인하대학교 정보통신대학원 무선전송연구실)
  • 투고 : 2010.06.28
  • 심사 : 2010.07.27
  • 발행 : 2010.08.31
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초록

본 논문에서는 다중 안테나를 사용하는 인지무선 시스템과 허가된 사용자(주사용자)가 공존하는 환경을 고려한다. 여기에서 부사용자 송신기는 직교 시공간 부호(OSTBC)를 사용하고 수신기는 Maximum Likelihood(ML) 검출 방식을 사용한다. Flat 페이딩 채널에서 ML 검출기를 사용할 경우, 최적의 precoder는 고유 빔포밍 방법이다. 본 논문에서는 벡터의 유사성에 기반한 가중치를 적용하여 간섭을 최소화하는 선형 precoding 알고리즘을 제안한다. 시뮬레이션 결과를 통해 제안된 알고리즘이 기존의 ZF(Zero-forcing) 빔포밍보다 최소 2~8dB 우수한 간섭억압 능력을 보여 우수한 SER 성능과 최대 8bps/Hz의 Capacity 증가를 보이는 것으로 나타났다.

In this paper, we consider a linear precoding for the effective spectrum sharing in multiple-input multiple-output (MIMO) cognitive radio system where a secondary user coexists with primary users. The secondary user employs the orthogonal space time block coding (OSTBC) at the transmitter. Assuming a flat fading channel and a maximum-likelihood receiver, the optimum precoder forces transmission referred to as eigen-beamforming. In this paper, to eliminate the interference, ZF criterion based eigen-beamforming is not only used but also the precoding weight is chosen to cancel the remaining interference. This weight is computed by vector's likelihood. Simulation results show stronger interference suppression capability, better SER performance, and higher capacity than the algorithm in [4].

키워드

과제정보

연구 과제 주관 기관 : 한국연구재단, 정보통신산업진흥원

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