Robust adaptive beamforming using iterative adaptive approach

ABSTRACT

The performance of traditional reconstruction-based robust adaptive beamformers may degrade when the array is not well calibrated. This performance degradation is mainly caused by the Capon spectrum estimator which can not estimate the spatial power spectrum accurately. In contrast to existing approaches, we propose two new reconstruction-based robust adaptive beamformers by using the accurate iterative adaptive approach (IAA) spectrum to combat the covariance matrix uncertainties and the steering vector mismatches. The first one employs the low-complexity IAA (IAA-LC) algorithm to obtain the interference power estimates and reconstruct the interference-plus-noise covariance matrix (INCM) with the computational complexity further reduced. The second one reconstructs the INCM by updating the power estimates corresponding to each interference steering vector with the use of knowledge-aided IAA (IAA-KA) algorithm. The desired signal steering vector is corrected by searching for the direction corresponding to the maximum power, which circumvents the use of optimization program. Simulation results show that our proposed beamformers outperform the others and can achieve the robust performance in the cases of array model mismatches.

KEYWORDS:

• Robust adaptive beamforming
• covariance matrix reconstruction
• iterative adaptive approach
• power spectrum
• steering vector

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work has been supported by Fundamental Research Funds for the Central Universities [grant number HEUCF160401] and China Scholarship Council [grant number 201806680057].

Notes on contributors

Zhen Meng

Zhen Meng received the BS degree in marine engineering from Harbin Engineering University, Harbin, China, in 2015. He is currently working toward the PhD degree in control science and engineering at the College of Automation, Harbin Engineering University, Harbin, China. His research interests include robust adaptive beamforming, array signal processing and radar signal processing.

Weidong Zhou

Weidong Zhou received the BS and MS degrees in automatic control from Harbin Institute of Technology in 1988, and Harbin University of Science and Technology in 1991, respectively. He received the PhD degree in navigation from Harbin Engineering University, China, in 2006. Since 2005, he has been a full professor at the College of Automation, Harbin Engineering University, China. His research interests include the direction of the automatic control theory, integration navigation, estimation theory, computer control, and multi-sensor data fusion.