针对大导向矢量失配误差造成传统自适应波束形成算法鲁棒性下降的问题,提出采用幅度响应约束的鲁棒自适应波束形成算法.该算法首先对接收数据协方差矩阵失配进行建模优化,然后根据已知的多径相干信号大致来波方向信息对波束主辩进行幅度响应约束,并利用所提引理将优化问题转化为迭代二阶锥规划问题,最后对权矢量直接进行求解获得最佳值.仿真结果表明:该算法能够针对多径相干信号形成多波束主辨,自由控制波束主瓣宽度和纹渡水平.当期望信号的方向偏差达到3.5°、输入信干噪比在-5~10 dB范围内变化时,该算法的阵列输出信干噪比优于不确定集类算法0~6 dB,对大导向矢量失配误差鲁棒性更高.
Aiming at degradation of robustness caused by large steering vector mismatch in the traditional adaptive beamforming algorithms, a robust adaptive beamforming algorithm by constraints on magnitude response is proposed. The receiving covariance matrix mismatch is modeling optimized, and the main lobe magnitudes are then constrained according to the known direction information of multiple coherent signals. The optimization case is converted into an iterative second-order cone programming (SOCP) via the presented lemma. Simulations show that this method enables to form beam main lobe in the direction of multiple coherent signals, and to control the width and the ripple level of the main lobe flexibly. When direction mismatch of the desired signal reaches 3.5° and the signal to noise ratio (SNR) varies within --5 dB to 10 dB, the array output signal to interference and noise ratio (SINR) in the proposed algorithm is superior to that in the uncertainty algorithm by 0-6 dB, and this algorithm is endowed with higher robustness against large steering vector mismatch.