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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Subspace-Based Adaptive Beamforming with Off-Diagonal Elements

비 대각요소를 이용한 부공간에서의 적응 빔 형성 기법

  • 최양호 (강원대학교 전기전자정보통신공학부) ;
  • 엄재혁 (강원대학교 전기전자정보통신공학부)
  • Published : 2004.01.01
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Abstract

Eigenstructure-based adaptive beamfoming has advantages of fast convergence and the insentivity to errors in the arrival angle of the desired signal. Eigen-decomposing the sample matrix to extract a basis for the Sl (signal plus interference) subspace, however, is very computationally expensive. In this paper, we present a simple subspace based beamforming which utilizes off-diagonal elements of the sample matrix to estimate the Sl subspace. The outputs of overlapped subarrays are combined to produce the final adaptive output, which improves SINR (signal-to-interference-plus-noise ratio) comapred to exploiting a single subarray. The proposed adaptive beamformer, which employs an efficient angle estimation is very roubust to errors in both the arrival angles and the number of the incident signals, while the eigenstructure-based beamforer suffers from severe performance degradation.

공분산 행렬의 고유구조에 기초한 뎀 형성 방법은 수렴속도가 빠르고 도래각 추정 오차에 둔감한 이점을 가지고 있다 그러나 Sl (signal Plus interference) 부공간에 대한 기저(basis)를 추정하기 위해 표본 행렬을 고유분해 하는 것을 필요로 하여 그 계산이 매우 복잡하다. 본 논문에서는 표본행렬의 비 대각 요소를 이용하여 턱 공간을 추정하는 간단한 빔 형성 기법을 제안한다. 제안한 방법에서는 중첩된 부어레이들의 빔을 결합하여 최종 적응 출력을 얻는다. 이와 같이 부어레이를 결합하면 하나의 부어레이를 이용하는 경우에 비해 SINR (signal-to-interference-plus-noise ratio) 성능을 증가시킬 수 있다. 고유분해에 의한 방법은 원가는 신호의 도래각, 신호 수 모두에 오차가 있으면 심하게 성능이 저하되지만, 비 대각방법에서는 효율적인 도래각 추정기법을 적용하여 이러한 오차에 매우 둔감하다.

Keywords

References

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