On Diagonal Loading for Robust Adaptive Beamforming Based on Worst-Case Performance Optimization

• Published in: ETRI journal Vol. 29; no. 1; pp. 50 - 58
• Main Authors: Lin, Jing-Ran, Peng, Qi-Cong, Shao, Huai-Zong
• Format: Journal Article
• Language: Korean
• Published: 한국전자통신연구원 01.02.2007; ETRI
• Subjects: 전자/정보통신공학; worst-case performance optimization; Robust adaptive beamforming (RABF); optimal diagonal loading; performance analysis
• ISSN: 1225-6463; 2233-7326

Robust adaptive beamforming based on worst-case performance optimization is investigated in this paper. It improves robustness against steering vector mismatches by the approach of diagonal loading. A closed-form solution to optimal loading is derived after some approximations. Besides reducing the computational complexity, it shows how different factors affect the optimal loading. Based on this solution, a performance analysis of the beamformer is carried out. As a consequence, approximated closed-form expressions of the source-of-interest power estimation and the output signalto-interference-plus-noise ratio are presented in order to predict its performance. Numerical examples show that the proposed closed-form expressions are very close to their actual values.