基于NLS的MIMO雷达方向图综合

Nonlinear Least Square Based Beampattern Synthesis for MIMO Radar

与传统相控阵雷达方向图综合不同,MIMO雷达通过优化发射波形的协方差矩阵来实现发射方向图综合,从而实现数字阵列雷达的多功能特性。该文通过数学变换,把传统相控阵雷达非线性最小二乘方向图综合法推广到MIMO雷达方向图综合。首先对发射波形的协方差矩阵进行分解,然后构造非线性最小二乘法代价函数优化分解因子,从而使综合方向图最大限度地逼近期望方向图。与现有MIMO雷达方向图综合方法相比,文中方法能通过罚函数,灵活调节综合方向图的过渡带宽度和主瓣波动幅度,且具有更小的均方误差,仿真实验验证了方法的有效性。

Multiple-input multiple-output（MIMO） radar can achieve transmit beampattern synthesis by optimizing the covariance matrix of transmit waveform, which is different from traditional phase array radar, so as to achieve multifunction digital array radar（DAR）. In this paper, we extend the traditional nonlinear least square（NLS） based beampattern synthesis method to MIMO radar case by mathematic transform. We first decompose the covariance matrix of the transmit waveform. Then the cost function of NLS is constructed to optimize the decomposition factor, so as to obtain a desired spatial transmit heampattern. Compared with the existing beampattern synthesis methods for MIMO radar, the proposed method can adjust the width of transition region and mainlobe region ripple by changing the penalty function and has less mean square errors. Computer simulation results confirm the effectiveness of the algorithm.