基于多输入多输出雷达发射方向图综合的波形设计

针对多输入多输出(MIMO)雷达发射方向图匹配时阵元功率不均匀和发射波形存在较高峰均比等缺点,提出了一种新的MIMO雷达发射方向图综合方法。构造一组基矩阵,将协方差矩阵的求解等效为基矩阵系数的寻优问题,在简化寻优模型的基础上进一步将其转化为一个凸优化问题,以便采用原对偶内点算法进行有效求解;在基矩阵中引入单位矩阵,以保证发射阵元满足等功率辐射要求,同时将尺度因子作为变量进行联合寻优,克服优化方向图对期望波束模值的依赖,解决二者增益不匹配引起优化误差变大的问题;在得到发射波形的协方差矩阵后,利用矩阵分解和交替迭代法设计发射波形,每次迭代过程中利用凸优化理论对发射波形的模值上界进行严格约束,有效减小发射波形的峰均比。仿真实验表明,合成的发射方向图在有效地逼近期望波束的同时大大降低了发射波形的峰均比。

Waveform Design of MIMO Radar Based on Transmitting Pattern Synthesis

A new method about the transmitting pattern synthesis of multiple-input and multiple-output (MIMO) radar is proposed in order to maintain the uniform elemental power constraint and low peak-to-average power ratio (PAPR) of the transmitted waveform. A basis matrix set is constructed, which can convert the solution of covariance matrix into the optimization of the coefficients of basis matrix set. It can not only reduce the computing complexity of the original optimal model but also can be solved effectively by the primal-dual interior point method. The identity matrix is included in the basis matrix set, which can satisfy the uniform elemental power constraint. And the scale factor of the desired beam is set as the unite variance so as to reduce the matching error of the MIMO radar pattern. The matrix decomposition and alternate optimal method are used to design the transmitted waveform which can effectively descend the PAPR based on the convex optimization. The simulation results are presented to verify the efficiency of the proposed method.