双基地MIMO雷达发射功率聚焦的角度估计算法研究

Study on Angle Estimation of Bistatic MIMO Radar Based on Transmit Power Focus

该文针对传统双基地MIMO雷达发射功率在空间发散的问题,提出一种双基地MIMO雷达发射功率聚焦方法。首先,建立了双基地MIMO雷达发射功率聚焦的优化模型,其优化准则为:在感兴趣空域内严格约束优化波束与期望波束的最大误差小于给定门限的前提下,最小化发射方向图的峰值旁瓣功率。同时,构造特殊发射端波束矩阵,不仅能使等效发射/接收导向矢量具有旋转不变性,并且简化了原优化模型,以便采用二阶锥规划理论进行快速求解;其次,利用改进平行因子算法对空间目标的收发角度进行估计,结合发射/接收导向矢量的旋转不变性对平行因子内部最小二乘算法的初始迭代点进行了改进,有效地减小了算法的迭代步数;再次,推导了双基地MIMO雷达发射功率聚焦下多目标角度估计的克拉美罗界(CRB),进一步说明了所提方法的优越性。最后,仿真验证了理论分析的有效性。

In order to solve the problem that the power is transmitted dispersedly in traditional bistatic MIMO radar, a method about the transmit power focus of the bistatic MIMO radar is proposed. Firstly, the mathematic model is constructed based on an effective optimal criterion that can not only constrain the maximum error of the optimal beam and the desire one less than the given value, but also minimize the peak side lobe power of the transmit pattern. At the same time, a special beam matrix of transmitting terminal is constructed, not only making equivalent transmit/receive steering vector possessing the character of rotational invariance property, but also simplifying the original optimized model in order to be fast solved via second-order cone programming theory. Secondly, the transmitting and receiving angle of space target is estimated by utilizing improved PARallel FACtor（PARFAC） algorithm. The initial iteration point in the least square algorithm of PARFAC interior is improved by integrating into rotation invariance of transmitting/receiving steering vector, which can effectively decrease the number of iteration. Furthermore, the Cramer-Rao Bound of multi-target angle estimation under bistatic MIMO radar transmitting power focusing is derived which prove the superiority of the proposed method. Finally, the simulation results show the effectiveness of the theoretical analysis.