基于改进广义线性组合算法的极化阵列稳健波束形成

为提升极化阵列波束形成的稳健性，将广义线性组合(general linear combination, GLC)算法应用于极化阵列. 分析了GLC算法在较高输入信噪比条件下，阵列存在阵元扰动和期望信号(signal of interest, SOI)波达方向(direction of arrival, DOA)误差时，输出的信干噪比随快拍数增加而下降的原因，并提出了一种结合转换函数的改进GLC算法. 所提算法根据采样协方差矩阵(sample covariance matrix, SCM)特征值相关参数的大小，对信噪比进行判断. 信噪比较高时，采用改进GLC算法计算对角加载量(diagonal loading level, DLL)；信噪比较低时，采用原GLC算法计算DLL，从而使得所提算法在任意输入信噪比和快拍下的输出信干噪比均大于或等于原GLC算法. 通过主瓣干扰条件下的计算机仿真实验验证了所提算法的有效性. 

Robust Beamforming of Polarization Array Based on an Improved General Linear Combination Algorithm

To improve the robustness of beamforming for polarization array, a general linear combination (GLC) algorithm was applied to the polarization array in this paper. Firstly, analyzing the reason of output signal to interference plus noise ratio decrease with the increase of the number of snapshots under the conditions of sensor disturbance and direction of arrival (DOA) mismatch of the signal of interest (SOI) at high input signal to noise ratio, an improved GLC algorithm was proposed. And then, the input signal to noise ratio was identified by the proposed algorithm according to the size of parameters related to the eigenvalues of the sample covariance matrix (SCM). At high input signal to noise ratio, the GLC algorithm combined with the conversion function was used to calculate the diagonal loading level (DLL). And at a low level of the input signal to noise ratio, the original GLC algorithm was used to calculate the DLL, making the output signal to interference plus noise ratio of the improved GLC algorithm be greater than or equal to that of the original GLC algorithm under any input signal to noise ratio and snapshot. Finally, the effectiveness of the proposed algorithm was verified by simulations under the condition of mainlobe interference.