ETRI Journal
- Volume 29 Issue 1
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- Pages.50-58
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- 2007
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- 1225-6463(pISSN)
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- 2233-7326(eISSN)
On Diagonal Loading for Robust Adaptive Beamforming Based on Worst-Case Performance Optimization
- Lin, Jing-Ran (School of Communication and Information Engineering, University of Electronic Science and Technology of China) ;
- Peng, Qi-Cong (School of Communication and Information Engineering, University of Electronic Science and Technology of China) ;
- Shao, Huai-Zong (School of Communication and Information Engineering, University of Electronic Science and Technology of China)
- Received : 2005.09.23
- Published : 2007.02.28
Abstract
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.
Keywords
- Robust adaptive beamforming (RABF);
- optimal diagonal loading;
- worst-case performance optimization;
- performance analysis