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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Channel Estimation Scheme Using Modified ICA in MIMO-OFDM Systems

MIMO-OFDM 시스템에서 Modified ICA를 이용한 채널 추정 기법

  • 김종득 (시립인천대학교 전자공학과 신호처리 연구실) ;
  • 변윤식 (시립인천대학교 전자공학과 신호처리 연구실)
  • Published : 2006.05.01
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Abstract

If channel coefficients errors exist in MIMO-OFDM systems, the performance degradation of systems will occurs. In order to improve the performance of MIMO-OFDM systems, the technique of obtaining accurate channel estimation in multipath fading channel is necessary. In this paper, we introduce and propose new channel estimation-modified ICA algorithm. Simulation results shows from BER and SER curves which compare the proposed algorithm under time-varying Rayleigh fading with perfect known channel. The result of channel estimation by the proposed algorithm in this simulation, it shows that PDF(amplitude of channel) are close to the case with perfect known channel at the receiver with respect to uncoded QPSK/16-QAM/64-QAM modulation. Also, we can see that BER and SER curves are very close to the case with perfect known channel. Therefore, we see that the proposed algorithm have a good performance in MIMO-OFDM systems.

MIMO-OFDM 방식에서 추정된 채널 계수에 추정 오차가 있다면, 시스템의 성능 저하가 발생하게 된다. MIMO-OFDM 방식의 성능을 향상시키기 위해서는 무엇보다도 다중 경로 페이딩 환경에서 정확하게 채널을 추정 할 수 있는 기술이 필요하다. 본 논문에서는 다중 경로 시변 페이딩 채널하에서의 modified ICA (Independent Component Analysis)을 이용하여 수신된 신호로부터 각 송신 안테나의 송신 신호를 분리한 후, 채널을 추정하여 검파하는 새로운 채널 추정 방식인 Modified ICA 알고리즘을 소개하고, 제안하고자 한다. 본 논문에서 제안된 Modified ICA를 이용한 MIMO-OFDM 시스템에서의 채널 추정에 대한 모의실험 결과, perfect hewn channel 대해 Uncoded QPSK,16-QAM, 64-QAM의 SER과 BER 성능 비교 곡선이 매우 근접함을 알 수 있다. 따라서 제안된 알고리즘이 MIMO-OFDM 시스템에서 우수한 성능을 지니고 있음을 보여 주고 있다.

Keywords

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