The interference from clutter and active electromagnetic equipment deteriorates target detection performance greatly. In this paper, we design a MIMO radar transmit matrix to improve target detection performance in the presence of interference. To this end, we model the design problem by maximizing the signal to interference ratio (SIR) with the constraints of spectrum compatibility and constant modulus. To solve the resulting complicated optimization problem, the hierarchical approach is employed to convert the original problem into two subproblems, i.e., transmit design for sidelobe interference suppression and signal design for target detection under mainlobe interference. The first subproblem is solved by a novel anti-sidelobe-interference algorithm named as hybrid beampattern synthesizing (HBS) which can achieve lower nulling levels than the well-known beampattern synthesizing methods. The second subproblem is solved by two steps composed of energy spectrum density (ESD) design and signal design via the proposed hybrid ESD matching (HEM) algorithm which can balance the matching loss and the spectrum compatibility more flexibly than the existing ESD matching methods. Numerical examples verify the advantages of the proposed algorithms and that the designed MIMO radar transmit waveform can achieve higher output SIR than the traditional waveform.

杂波和有源电磁设备的干扰会大大降低目标检测性能。在本文中，我们设计了MIMO雷达发射矩阵，以在存在干扰的情况下提高目标检测性能。为此，我们通过在频谱兼容性和恒定模量的约束下最大化信噪比（SIR）来对设计问题进行建模。为了解决由此产生的复杂的优化问题，采用分层方法将原始问题转换为两个子问题，即用于旁瓣干扰抑制的发射设计和用于主瓣干扰下的目标检测的信号设计。第一个子问题是通过一种称为混合波束图形合成（HBS）的新型抗旁瓣干扰算法来解决的，该算法可以实现比众所周知的波束图形合成方法更低的归零水平。第二个子问题通过提出的混合ESD匹配（HEM）算法通过能谱密度（ESD）设计和信号设计两个步骤解决，与现有ESD匹配方法相比，该算法可以更灵活地平衡匹配损耗和频谱兼容性。数值算例验证了所提算法的优势，所设计的MIMO雷达发射波形可以实现比传统波形更高的输出SIR。第二个子问题通过提出的混合ESD匹配（HEM）算法通过能谱密度（ESD）设计和信号设计两个步骤解决，与现有ESD匹配方法相比，该算法可以更灵活地平衡匹配损耗和频谱兼容性。数值算例验证了所提算法的优势，所设计的MIMO雷达发射波形可以实现比传统波形更高的输出SIR。第二个子问题通过提出的混合ESD匹配（HEM）算法通过能谱密度（ESD）设计和信号设计两个步骤解决，与现有ESD匹配方法相比，该算法可以更灵活地平衡匹配损耗和频谱兼容性。数值算例验证了所提算法的优势，所设计的MIMO雷达发射波形可以实现比传统波形更高的输出SIR。