volume | PIER Journals

Abstract

In this paper, an efficient wideband array adaptive beamforming (ADBF) approach based on keystone transform is presented. In order to eliminate the aperture effect of the wideband signal, the modified keystone transform is applied to remove the time delay between different array elements. Thus, the wideband array is equivalent to the narrowband array, and the orthogonal projection matrix of the target steering vector can be used to filter the desired signal in the training samples, which avoids the signal cancellation caused in the estimation of ADBF covariance matrix. Compared with theestablished algorithm of sliding window, this approach can significantly reduce the computational burden. The feasibility and effectiveness of the proposed method are validated through numerical simulations.

1. Wang, J., D.-D. Cai, and F. Yang, "Aperture effect in uence and analysis of wideband phased array radar," Procedia Engineering, 2012.

2. Zhu, X. and Z. Kai, "A study on compensation of aperture fill time based onfrequency-shifting," International Radar Conference, IET, 2013.

3. Zhang, C. and Q. Lai, "Research on phased array radar affected by aperture fill time," Journal of Microwave Science, Vol. 33, No. 04, 67-69, 2017.

4. Frost, III, O. L., "An algorithm for linearly constrained adaptive array processing," Proc. IEEE, Vol. 60, No. 8, 926-935, 1972.
doi:10.1109/PROC.1972.8817

5. Hoffman, A. and S. M. Kogon, "Subband STAP in wideband radar systems," Proceedings of the 2000 IEEE Sensor Array and Multichannel Signal Processing Workshop, IEEE, 2000.

6. Zhang, P., Z. Yang, G. Jing, et al. "Adaptive beamforming via desired signal robust removal for interference-plus-noise covariance matrix reconstruction," Circuits Systems & Signal Processing, Vol. 40, No. 3, 2021.

7. Hu, P., M. Shen, C. Liang, et al. "An efficient broadband adaptive beamforming algorithm based on frequency-space cascade processing," Circuits Systems & Signal Processing, Vol. 37, No. 1, 1-12, 2017.

8. Bao, Z., M. Xing, and T. Wang, Radar Imaging Technology, Beijing Publishing House of Electronics Industry, 2005.

9. Yi, H., C. Y. Fan, J. G. Yang, et al. "Imaging and locating multiple ground moving targets based on keystone transform and FrFT for single channel SAR system," 2nd Asian-Pacic Conference onSynthetic Aperture Radar, 2009, APSAR 2009, 2009.

10. Jiao, Z. and Z. Wei, "A novel detection method based on generalized keystone transform and RFT for high-speed maneuvering target," International Symposium on Computational Intelligence & Design, IEEE, 2016.

11. Wang, N., M. Zhou, B. Zhong, et al. "Wideband signal DOA estimation method based on keystone transform," The Journal of Engineering, Vol. 4, 2019.
doi:10.31186/jenggano.4.1.1-11

12. Zhang, N., X. Tang, and J. Tang, "Broadband beamforming method based on keystone transform pre-processing," Journal of Tsinghua University (Science and Technology), Vol. 53, No. 7, 991-994, 2013.

13. Subbaram, H. and K. Abend, "Interference suppression via orthogonal projections: A performance analysis," IEEE Sixth Sp Workshop on Statistical Signal & Array Processing, IEEE Xplore, 1993.

14. Wang, Y., W. Sheng, and X. Chen, "A fast orthogonal projection beamforming algorithm for planar antenna arrays," Radar Science and Technology, Vol. 17, No. 3, 339-344, 2019.

15. Wang, J. and Y. Zhao, "Research on keystone transform implementation method," Fire Control Radar Technology, Vol. 40, No. 1, 45-51, 2011.

16. Chen, S., L. Huang, and L. Yu, "Variable PRF sampling spotlight SAR imaging based onimproved sinc interpolation," Journal of Radars, Vol. 8, No. 4, 527-536, 2019.

17. Shackelford, A. K., K. Gerlach, and S. D. Blunt, "Partially adaptive STAP using the FRACTA Algorithm," IEEE Transactions on Aerospace & Electronic Systems, Vol. 45, No. 1, 58-69, 2009.
doi:10.1109/TAES.2009.4805263

18. Xu, Z. H., M. Z. Chen, and B. Rao, "The optimal LCMV beamformer under multiple desired signals case," International Radar Conference, IET, 2013.

Dr. Yiyang Jiang

Prof. Mingwei Shen

Dr. Guodong Han