Colocated MIMO radar waveform-design based on two-step optimizations in spatial and spectral domains

提出一种基于空频域二步优化的集中式MIMO雷达波形设计方法。首先,利用最小积分旁瓣策略,形成带有零陷的期望发射方向图。针对所形成的非凸优化问题,利用隐藏的凸优化性能,通过半正定松弛和谱分解,可以在多项式时间内有效取得全局最优解。其次,针对空域优化得到的发射波形,引入相位变换对角矩阵并通过类幂方法迭代优化,在不影响雷达空域发射方向图基础上,雷达发射波形可在频域上进一步优化,从而避免对其他无线电设备造成干扰。实验仿真和现有方法对比分析证明了所提算法的有效性。

We propose an efficient colocated multiple-input multiple-output radar waveform-design method based on two-step optimizations in the spatial and spectral domains. First, a minimum integrated side-lobe level strategy is adopted to obtain the desired beam pattern with spatial nulling. By recovering the hidden convexity of the resulting fractional quadratically constrained quadratic programming non-convex problem, the global optimal solution can be achieved in polynomial time through a semi- definite relaxation followed by spectral factorization. Second, with the transmit waveforms obtained via spatial optimization, a phase changing diagonal matrix is introduced and optimized via power method-like iterations. Without influencing the shape of the optimized beam pattern, the transmit waveforms are further optimized in the spectral domain, and the desired spectral nulling is formed to avoid radar interference on the overlaid licensed radiators. Finally, the superior performance of the proposed method is demonstrated via numerical results and comparisons with other approaches to waveform design.