Antenna geometry optimization for 2D direction-of-arrival estimation for radar imaging
Antenna geometry optimization for 2D direction-of-arrival estimation for radar imaging
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用于雷达成像二维到达方向估计的天线几何优化
DOI：
10.1109/wsa.2011.5741909
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Bin Yang
中科院分区：
文献类型：
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作者：
Oliver Lange;Bin Yang
本文主要研究二维波达方向（DOA）估计中传感器阵列的二维几何优化问题。这种阵列可用于雷达成像目的。由于优化，阵列通道的数量可以保持相当小，这降低了硬件成本，同时可以实现高精度的DOA估计精度。因此，我们推导出2D Cramér-Rao界（CRB）的非常简单的表达式。通过最小化CRB的几何相关部分，可以减小DOA估计的细微误差方差。此外，我们定义了一个修改后的波束图的单源的情况下，这是有效的所有物理上可能的DOA的。通过改变其旁瓣电平，可以控制DOA野值的概率。此外，外部条件，如可能的DOA的范围和感兴趣的DOA区域也包括在优化过程中，以调整阵列的外部要求。通过这种方法，可以实现最佳的（单源）二维DOA估计性能的特定问题。作为优化算法，我们使用一种进化策略。为了显示优化阵列的DOA估计精度的提高，给出了仿真结果，并与标准的1D和2D阵列几何形状进行了比较。为了进行实证验证，我们已经开发了一个77 GHz的原型雷达传感器与16 RX通道。优化的2D阵列的几何形状实现与微带贴片。为了估计目标的距离和相对速度，我们采用调频连续波信号处理。为了展示这种雷达成像传感器的功能，我们提出了一些测量结果。
This paper focuses on the optimization of the 2D geometry of sensor arrays for 2D direction-of-arrival (DOA) estimation. Such arrays can be used for radar imaging purposes. Due to the optimization, the number of array channels can be kept quite small, which reduces hardware costs, while highly accurate DOA estimation accuracy can be achieved. Therefore, we derive a very simple expression of the 2D Cramér-Rao bound (CRB). By minimizing the geometry dependent part of the CRB, we can reduce the fine error variance of DOA estimation. In addition, we define a modified beampattern for the single source case, which is valid for all physically possible DOA's. By varying its side lobe level, the probability of DOA outliers can be controlled. Furthermore, external conditions such as the range of possible DOA's and the DOA region of interest are also included in the optimization process to adjust the array to external requirements. By this means, optimum (single source) 2D DOA estimation performance can be achieved for a specific problem. As optimization algorithm, we use an evolution strategy. To show the improvement in DOA estimation accuracy of the optimized arrays, simulation results are presented and compared to standard 1D and 2D array geometries. For empirical validation, we have developed a 77 GHz prototype radar sensor with 16 RX channels. The optimized 2D array geometry is realized with microstrip patches. To estimate the distance and the relative velocity of targets, we apply frequency modulated continuous wave signal processing. In order to show the functionality of this radar imaging sensor, we present some measurement results.