Zhou Wei, Zhang De-min, Wu Bo, Zhou Zheng-zhong. Study on Interference Suppression for LCMV Adaptive Array in Coherent Environment[J]. Journal of Electronics & Information Technology, 2007, 29(7): 1604-1607. doi: 10.3724/SP.J.1146.2005.01573
Citation:
Zhou Wei, Zhang De-min, Wu Bo, Zhou Zheng-zhong. Study on Interference Suppression for LCMV Adaptive Array in Coherent Environment[J]. Journal of Electronics & Information Technology, 2007, 29(7): 1604-1607. doi: 10.3724/SP.J.1146.2005.01573
Zhou Wei, Zhang De-min, Wu Bo, Zhou Zheng-zhong. Study on Interference Suppression for LCMV Adaptive Array in Coherent Environment[J]. Journal of Electronics & Information Technology, 2007, 29(7): 1604-1607. doi: 10.3724/SP.J.1146.2005.01573
Citation:
Zhou Wei, Zhang De-min, Wu Bo, Zhou Zheng-zhong. Study on Interference Suppression for LCMV Adaptive Array in Coherent Environment[J]. Journal of Electronics & Information Technology, 2007, 29(7): 1604-1607. doi: 10.3724/SP.J.1146.2005.01573
In environment with coherent interferences, performance of adaptive array will decline dramatically, and the general solution is spatial smoothing. However, adaptive array utilizing conventional Uniform Spatial Smoothing (USS) has poor ability to suppress coherent interferences, and it will lose the aperture of array. In the paper, an improved approach to suppress coherent interferences is proposed. Firstly, the paper presents an adaptive Weighted-Spatial-Smoothing (WSS) algorithm, which, through weighted averaging of the correlation matrices of each sub-array, can de-correlate the coherent interferences effectively. And then, based on WSS, using the Linear-Constrained-Minimum-Variance (LCMV) criterion, the optimal weight vector of sub-array beamformer can be obtained. Finally, considering the phase relationship of each sub-array, an approach for full array beamforming is proposed. The approach highly improvs the arrays ability to suppress the coherent interferences, and avoids the loss of aperture caused by conventional spatial smoothing. Theoretical analysis and computer simulation confirm the availability and robustness of the algorithm.
[1] Liberti J C and Rappaport T S. Smart Antennas for Wireless Communications: IS-95 and Third Generation CDMA Applications[M]. New Jersey: Prentice Hall PTR, 1999: chapter3, chapter9. [2] 龚耀寰著. 自适应滤波(第二版)时域自适应滤波和智能天线[M]. 北京: 电子工业出版社, 2003, 第一章. [3] 周围,周正中,张德民. 基于高阶累积量的空间特征估计方法[J]. 信号处理,2005, 21(4A): 61-64. [4] Evans J E, Johnson J R, and Sun D F. High resolution angular spectrum estimation techniques for terrain scattering analysis and angle of arrival estimation [A]. IEEE 1st ASSP Workshop on Spectral Estimation[C], Canada, 1981: 134-139. [5] Shan T J, Wax M, and Kailath T. On spatial smoothing for direction-of-arrival estimation of coherent signals[J].IEEE Trans. on ASSP.1985, 33(4):806-811 [6] Pillai S U and Kwon B H. Forward-backward spatial smoothing techniques for the coherent signal identification [J].IEEE Trans. on ASSP.1989, 37(1):8-15 [7] 王布宏,王永良,陈辉. 相干信源波达方向估计的加权空间平滑算法[J].通信学报,2003, 24(4): 31-40. [8] Tan K C and Oh G L. Estimating directions of arrival of coherent signals in unknown correlated noise via spatial smoothing[J].IEEE Trans. on Signal Processing.1997, 45(4):1087-1091 [9] Widrow B, et al.. Signal cancellation phenomena in adaptive antennas: causes and cures [J]. IEEE Trans. on Antennas and Propagation, 1982, AP-30(3): 469-478.