Optimal Adaptive Robust Beamforming

 

The performance degradation in traditional adaptive beamformers can be attributed to the imprecise knowledge of the array steering vector and inaccurate estimation of the covariance matrix. The inaccurate estimation of the covariance matrix is due to the limited data samples and presence of desired signal components in the training data, especially when the desired signal is the dominant signal in the training data. The mismatch between the actual and the presumed steering vectors can be due to the error in the position (geometry) and/or in the look direction estimate. Due to mismatch in the actual and the presumed steering vectors and the inaccurate estimation of covariance matrix, the output SINR of the adaptive beamformers cannot adapt to the increase in the input SNR. In other words, the output SINR of the adaptive beamformers saturates as the input SNR increases. From the graphs in our 3 publications, it can be observed that the  algorithms proposed by us (Mallipeddi et al, 3 articles listed below) were able to overcome the effect of saturation. The results of our proposed algorithms were compared with some of the state-of-the-art algorithms such as RCB, IRCB, SQP and many others. We present the performance graphs of different algorithms in terms of output SINR for different input SNR in a pdf document that can be downloaded from the link below:


The full document is available here as a pdf file.

References

Mallipeddi R., J. P. Lie, P. N. Suganthan, S. G. Razul, and C. M. S. See, "Near optimal robust adaptive beamforming approach based on evolutionary algorithm," Progress In Electromagnetics Research B, Vol. 29, 157-174, 2011.

Mallipeddi R., J. P. Lie, P. N. Suganthan, S. G. Razul, and C. M. S. See, "Robust adaptive beamforming based on covariance matrix reconstruction for look direction mismatch," Progress In Electromagnetics Research - Letters, Vol. 25, pp 37-46, 2011.

R. Mallipeddi J. P. Lie, P. N. Suganthan, S. G. Razul, and C. M. S. See, "A differential evolution approach for robust adaptive beamforming based on joint estimation of look direction and array geometry," Progress In Electromagnetics Research, Vol. 119, 381-394, 2011.

J. Li, P. Stoica, and Z. Wang, "On robust capon beamforming and diagonal loading," IEEE Transactions on Signal Processing, vol. 51, no. 7, pp. 1702 - 1715, 2003.

J. P. Lie, X. Li, W. Ser, C. M. S. See, and L. Lei, "Adaptive uncertainty based iterative robust capon beamformer," Proc. IEEE Int Acoustics Speech and Signal Processing (ICASSP), pp. 2526-2529, 2010.

 Z. L. Yu, Z. Gu, J. Zhou, Y. Li, S. Wee, M. H. Er, "A Robust Adaptive Beamformer Based on Worst-Case Semi-Definite Programming," IEEE Transactions on Signal Processing, vol. 58, no. 11, pp. 5914-5919, 2010.

Won S. Y., and Chong K. U., "Robust adaptive beamforming based on the eigenstructure method," IEEE Transactions on Signal Processing, Vol. 42, No.6, 1543-1547, June 1994.

Y. Selen, R. Abrahamsson, and P. Stoica, "Automatic robust adaptive beamforming via ridge regression," Signal Processing, vol. 88, no. 1, pp. 33 - 49, 2008.

El-Keyi A.,   Kirubarajan T.,   Gershman A.B., "Robust Adaptive Beamforming Based on the Kalman Filter," IEEE Transactions on Signal Processing, Vol. 53, Issue 8, pp. 3032-3041, August, 2005.

Selen Y.,   Abrahamsson R.,   Stoica P., "Automatic Robust Adaptive Beamforming via Ridge Regression," IEEE international conference on Acoustics, Speech and Signal Processing, ICASSP, pp. II-965 - II-968, April, 2007.

Lei Lei Lie J.P.,   Gershman A.B.,   See C.M.S.,  "Robust adaptive beamforming and steering vector estimation in partly calibrated sensor arrays: A structured uncertainty approach," IEEE international conference on Acoustics, Speech and Signal Processing, ICASSP , pp. 2534 - 2537, March, 2010.

Joni Polili Lie, Wee Ser, and Chong Meng Samson See, "Adaptive Uncertainty Based Iterative Robust Capon Beamformer Using Steering Vector Mismatch Estimation," IEEE Transactions on Signal Processing, Vol. 59, No. 9, September, 2011.

Hassanien A.,   Vorobyov S.A.,   Wong K.M., "Robust Adaptive Beamforming using Sequential Quadratic Programming," IEEE international conference on Speech and Signal Processing, ICASSP, pp. 2345-2348, 2008.

Lei Lei, Lie J.P.,  Gershman A.B.,  See C.M.S.  "Robust Adaptive Beamforming in Partly Calibrated Sparse Sensor Arrays," IEEE Transactions on Signal Processing, Vol. 58, Issue 3, March 2010.

Siew Eng Nai,   Wee Ser;   Zhu Liang Yu,   Huawei Chen"Iterative Robust Minimum Variance Beamforming," IEEE Transactions on Signal Processing, VOL. 59, NO. 4, APRIL 2011.

 

Prepared: September 2011