Robust beamforming for coherent signals based on the spatial-smoothing technique

Spatial-smoothing provides an elegant solution for both beamforming and direction of arrival (DOA) estimation in a coherent signal environment. However, this technique is based on special array structures such as uniform linear arrays (ULAs) and its performance will degrade when the special structure is destroyed by all kinds of array errors in practice. In this paper, the robust beamforming problem for coherent signals is addressed and a forward-only (FO) beamformer is proposed first based on worst-case optimization by considering both the steering vector and the correlation matrix errors. By treating the steering vector error differently, two solutions are derived, which are then extended to the forward-backward (FB) case with improved performance. By introducing a preprocessing matrix, real-valued closed-form solutions are then presented with the same performance as in the FB case, but with much lower computational complexity.

[1]  Lloyd J. Griffiths,et al.  A projection approach for robust adaptive beamforming , 1994, IEEE Trans. Signal Process..

[2]  L. J. Griffiths,et al.  An alternative approach to linearly constrained adaptive beamforming , 1982 .

[3]  Thomas Kailath,et al.  Adaptive beamforming for coherent signals and interference , 1985, IEEE Trans. Acoust. Speech Signal Process..

[4]  Jian Li,et al.  Fully Automatic Computation of Diagonal Loading Levels for Robust Adaptive Beamforming , 2010, IEEE Transactions on Aerospace and Electronic Systems.

[5]  Wei Liu,et al.  Robust forward backward based beamformer for a general-rank signal model with real-valued implementation , 2012, Signal Process..

[6]  L. Griffiths,et al.  An adaptive generalized sidelobe canceller with derivative constraints , 1986 .

[7]  O. L. Frost,et al.  An algorithm for linearly constrained adaptive array processing , 1972 .

[8]  A. Elnashar,et al.  Further Study on Robust Adaptive Beamforming With Optimum Diagonal Loading , 2006, IEEE Transactions on Antennas and Propagation.

[9]  B. Breed,et al.  A short proof of the equivalence of LCMV and GSC beamforming , 2002, IEEE Signal Processing Letters.

[10]  S. Unnikrishna Pillai,et al.  Forward/backward spatial smoothing techniques for coherent signal identification , 1989, IEEE Trans. Acoust. Speech Signal Process..

[11]  S. Weiss,et al.  Constrained adaptive broadband beamforming algorithm in frequency domain , 2004, Processing Workshop Proceedings, 2004 Sensor Array and Multichannel Signal.

[12]  Ning Ma,et al.  Adaptive beamforming with joint robustness against mismatched signal steering vector and interference nonstationarity , 2004, IEEE Signal Processing Letters.

[13]  Zhi-Quan Luo,et al.  Robust adaptive beamforming for general-rank signal models , 2003, IEEE Trans. Signal Process..

[14]  Harry L. Van Trees,et al.  Optimum Array Processing , 2002 .

[15]  Petre Stoica,et al.  Robust Capon beamforming in the presence of coherent interference , 2003 .

[16]  Wei Liu,et al.  Wideband Beamforming: Concepts and Techniques , 2010 .

[17]  Zhi-Quan Luo,et al.  Robust adaptive beamforming using worst-case performance optimization: a solution to the signal mismatch problem , 2003, IEEE Trans. Signal Process..

[18]  R. Langley,et al.  Adaptive Beamforming with Real-Valued Coefficients Based on Uniform Linear Arrays , 2011, IEEE Transactions on Antennas and Propagation.

[19]  M. Viberg,et al.  Two decades of array signal processing research: the parametric approach , 1996, IEEE Signal Process. Mag..

[20]  Jian Li,et al.  On robust Capon beamforming and diagonal loading , 2003, 2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03)..

[21]  Harry L. Van Trees,et al.  Detection, Estimation, and Modulation Theory: Radar-Sonar Signal Processing and Gaussian Signals in Noise , 1992 .

[22]  L. Godara.  Application of antenna arrays to mobile communications. II. Beam-forming and direction-of-arrival considerations , 1997, Proc. IEEE.

[23]  Chengwen Xing,et al.  On Low Complexity Robust Beamforming With Positive Semidefinite Constraints , 2009, IEEE Transactions on Signal Processing.

[24]  Harry L. Van Trees,et al.  Optimum Array Processing: Part IV of Detection, Estimation, and Modulation Theory , 2002 .

[25]  Henry Cox,et al.  Robust adaptive beamforming , 2005, IEEE Trans. Acoust. Speech Signal Process..