Frequency diverse array multiple-input multiple-output (FDA-MIMO) radar produces an angle-range-dependent and time-varying transmit beampattern due to the small frequency increment across its array elements, which provides potential applications in new radar techniques. In this paper, we first establish a FDA-MIMO radar receiver model in the presence of spectral interferences, which focuses on the interference covariance matrix structure when the transmitted baseband signals are time- or frequency-domain orthogonal. Then, we show that the FDA-MIMO radar has a capability in suppressing spectral interferences with low computational complexity. Specifically, we propose an adaptive transmit weight vector for element-wise power allocation through maximizing the output signal-to-interference-plus-noise ratio (SINR). Furthermore, we propose a shrinkage-to-tapering algorithm for covariance matrix estimation in a coherent process interval. The interference-plus-noise covariance matrix is reconstructed accordingly with prior knowledge including the target, interference and noise covariance matrix structures. Numerical results demonstrate that the FDA-MIMO radar with adaptive power allocation can suppress spectral interferences by the developed method and high output SINR is achieved.

中文翻译：

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FDA-MIMO 自适应发射功率分配的协方差矩阵估计

频分阵列多输入多输出 (FDA-MIMO) 雷达由于其阵列元素的频率增量很小，因此会产生与角度范围相关且随时间变化的发射波束图案，这为新雷达技术提供了潜在应用。在本文中，我们首先建立了存在频谱干扰的FDA-MIMO雷达接收机模型，该模型重点研究了发射基带信号时域或频域正交时的干扰协方差矩阵结构。然后，我们证明了 FDA-MIMO 雷达具有抑制频谱干扰的能力，计算复杂度低。具体来说，我们通过最大化输出信干噪比 (SINR)，提出了一种自适应发射权重向量，用于按元素进行功率分配。此外，我们提出了一种在相干过程区间内进行协方差矩阵估计的收缩到锥度算法。利用包括目标、干扰和噪声协方差矩阵结构的先验知识相应地重构干扰加噪声协方差矩阵。数值结果表明，具有自适应功率分配的FDA-MIMO雷达可以通过所开发的方法抑制频谱干扰，并实现了高输出SINR。