Abstract：In order to solve the problem of adaptive beamformer performance degradation due to few snapshots and mainlobe angle mismatch, a robust dominant mode rejection adaptive beamforming algorithm based on modified covariance matrix is proposed. The algorithm employs modified covariance matrix to estimate dominant mode component and reconstructs covariance matrix. Then, the signal subspace is obtained by projecting the steering vector of the desired signal onto eigenvector of the reconstructed covariance matrix, for enhancing the performance of algorithm at low SNR, the algorithm uses the principal eigenvector of a positive define matrix which integrates the desired signal region to modify signal subspace, thus calibrated steering vector of the desired signal is obtained by projecting the presumed steering vector onto the modified signal subspace. Finally, the optimal weight is obtained from the reconstructed covariance matrix and the calibrated steering vector. Theoretical analysis and simulation show the effectiveness and robustness of the proposed algorithm.
ABRAHAM D A and OWSLEY N L. Beamforming with dominant mode rejection[C]. IEEE OCEANS Conference, Washington, 1990: 470-475. doi: 10.1109/ OCEANS.1990. 584812.
[2]
DU Lin, LI Jian, and PETER S. Fully automatic computation of diagonal loading levels for robust adaptive beamforming[J]. IEEE Transactions on Aerospace and Electronic Systems, 2010, 46(1): 449-458. doi: 10.1109/TAES. 2010.5417174.
[3]
ZHANG W, WANG J, and WU S. Robust Capon beamforming against large DOA mismatch[J]. Signal Processing, 2013, 93(4): 804-810. doi: 10.1016/j.sigpro.2012. 10.002.
[4]
FELDMAN D D and GRIFFITHS L J. A projection approach for robust adaptive beamforming[J]. IEEE Transactions on Signal Processing, 1994, 42(4): 867-876. doi: 10.1109/78.285650.
[5]
FELDMAN D D and GRIFFITHS L J. A constraint projection approach for robust adaptive beamforming[C]. Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing, Toronto, Canada, 1991: 1381-1384. doi: 10.1109/ICASSP.1991.150680.
[6]
LI Jian, PETER S, and WANG Z. On robust Capon beamforming and diagonal loading[J]. IEEE Transactions on Signal Processing, 2003, 51(7): 1702-1715. doi: 10.1109/TSP. 2003.812831.
[7]
CAPON J. High-resolution frequency-wavenumber spectrum analysis[J]. Proceedings of the IEEE, 1969, 57(8): 1408-1418. doi: 10.1109/PROC.1969.7278.
[8]
YU L, LIU W, and LANGLEY R. SINR analysis of the subtraction-based SMI beamformer[J]. IEEE Transactions on Signal Processing, 2010, 58(11): 5926-5932. doi: 10.1109/TSP. 2010.2058801.
[9]
ZHANG L, LIU W, and YU L. Performance analysis for finite sample MVDR beamformer with forward backward processing[J]. IEEE Transactions on Signal Processing, 2011, 59(5): 2427-2431. doi: 10.1109/TSP.2011.2109957.
[10]
JOHN E, RUSSEL C, and MARK E. Comment on mofied MUSIC algorithm for estimating DOA of signals[J]. Signal Processing, 1996, 55(2): 253-254. doi: 10.1016/S0165- 1684(96)00179-X.
[11]
WAGE K E and BUCK J R. Snapshot performance of the dominant mode rejection beamformer[J]. IEEE Journal of Oceanic Engineering, 2014, 39(2): 212-225. doi: 10.1109/JOE. 2013.2251538.
[12]
WAGE K E and BUCK J R. SINR loss of the dominant mode rejection beamformer[C]. IEEE International Conference on Acoustics, Speech and Signal Processing, Brisbane, Queensland, 2015: 2499-2503. doi: 10.1109/ICASSP.2015. 7178421.
[13]
JOSE A D S and KATHLEEN E W. An improved whitening transformation for snapshot-deficient scenarios[C]. OCEANS 2015 MTS/IEEE Washington, 2015: 1-6. doi: 10.23919/ OCEANS.2015.7404410.
[14]
SHAN Chao, WU Y, and WANG Y. ESB-DMR beamforming
under random matrix theory judgment principle[C]. IET International Radar Conference, Hangzhou, China, 2015: 1-4. doi: 10.1049/cp.2015.1006.
[15]
SOMASUNDARAM S D and PARSONS N H. Evaluation of robust Capon beamforming for passive sonar[J]. IEEE Journal of Oceanic Engineering, 2011, 36(4): 686-695. doi: 10.1109/JOE.2011.2167374.
[16]
GU Y and LESHEM A. Robust adaptive beamforming based on interference covariance matrix reconstruction and steering vector[J]. IEEE Transactions on Signal Process, 2012, 60(7): 3881-3885. doi: 10.1109/TSP.2012.2194289.
[17]
HUANG L, ZHANG J, XU X, et al. Robust adaptive beamforming with a novel interference-plus-noise covariance matrix reconstruction method[J]. IEEE Transactions on Signal Processing, 2015, 63(7): 1643-1650. doi: 10.1109/TSP. 2015.2396002.
[18]
YUAN X and GAN L. Robust adaptive beamforming via a novel subspace method for interference covariance matrix reconstruction[J]. Signal Processing, 2017, 130: 233-242. doi: 10.1016/j.sigpro.2016.07.008.
