稀疏MIMO雷达实孔径三维成像技术

针对任意的多输入多输出(multiple-input multiple-output, MIMO)稀疏阵列提出了MIMO单快拍成像模式和相控阵多帧联合成像模式两种三维成像方法，并对两种模式下角度分辨率及信噪比(signal noise ratio, SNR) 进行了对比. MIMO单快拍成像模式角度分辨率等价于收发联合等效阵列；相控阵多帧联合成像模式的方向图等于发射方向图与接收方向图的乘积，同样也能获得收发联合等效阵列的角度分辨率；相控阵多帧联合成像模式与MIMO单快拍成像模式的SNR的比值为发射阵列数量. 讨论了稀疏阵列与均匀满阵之间的区别与联系，稀疏阵列的波束方向图等价于均匀满阵的二维加窗快速傅里叶变换(fast Fourier transform, FFT)，加窗使稀疏阵列方向图展宽. MIMO单块拍成像模式适用于对实时性要求高的应用场景，相控阵多帧联合成像模式适用于对SNR要求高的应用场景.

The 3D methods for sparse MIMO radar

For arbitrary multiple-input multiple-output (MIMO) sparse arrays, two 3D imaging methods are proposed, namely MIMO single-shot imaging mode and phased array multi-frame joint imaging mode. In this paper, we analyze the differences of the angular resolution and the SNR between those two modes. About the angular resolution, the MIMO mode is equivalent to the resolution of the virtual receiving array. As for the phased array mode, if we adopts the multi-frame jointed imaging method, the synthesized beam pattern is the product of the transmitting beam pattern and the receiving beam pattern, and the resolution is also equivalent to the resolution of the virtual receiving array. About the SNR, the ratio of the phased array mode to the MIMO mode is the number of the transmitting array. The difference and connection between sparse array and evenly full array are discussed, and the beam pattern of sparse array is equivalent to the 2D windowed fast Fourier transform(FFT) of evenly full array, and the 2D windowed FFT widens the pattern of sparse array. MIMO single-shot imaging mode is suitable for application scenarios with high real-time requirements, and phased array multi-frame joint imaging mode is suitable for application scenarios with high SNR requirements.