Wu Wei, Wang Yunfei, Zhang Xiaofei, Li Jianfeng
College of Electronic Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.
Institute of Manned Space System Engineering, China Academy of Space Technology, Beijing 100094, China.
Sensors (Basel). 2019 Apr 26;19(9):1961. doi: 10.3390/s19091961.
In this paper, we derive the discrete Fourier transform (DFT) method for direction of arrival (DOA) estimation by generating the massive virtual difference co-array with the nested array. By contrast with the spatial smoothing (SS) subspace-based methods for nested array, which halve the array aperture, the proposed method can take full advantage of the total array aperture. Since the conventional DFT method is a non-parametric method and is limited by Rayleigh threshold, we perform the phase rotation operation to obtain the fine DOA estimates. Owing to the full utilization of the array aperture and phase rotation operation, the proposed method can achieve better performance than SS subspace-based methods for far-field sources especially with massive virtual difference co-arrays which possess a large number of virtual sensors. Besides, as the fast Fourier transform (FFT) is attractive in practical implementation, the proposed method lowers the computational cost, as compared with the subspace-based methods. Numerical simulation results validate the superiority of the proposed method in both estimation performance and complexity.
在本文中，我们通过用嵌套阵列生成大量虚拟差分共阵列，推导了用于到达方向（DOA）估计的离散傅里叶变换（DFT）方法。与基于空间平滑（SS）子空间的嵌套阵列方法相比，后者会使阵列孔径减半，而本文提出的方法可以充分利用整个阵列孔径。由于传统DFT方法是非参数方法且受瑞利阈值限制，我们执行相位旋转操作以获得精确的DOA估计。由于充分利用了阵列孔径和相位旋转操作，本文提出的方法对于远场源可以实现比基于SS子空间的方法更好的性能，特别是对于拥有大量虚拟传感器的大量虚拟差分共阵列。此外，由于快速傅里叶变换（FFT）在实际实现中很有吸引力，与基于子空间的方法相比，本文提出的方法降低了计算成本。数值模拟结果验证了本文提出的方法在估计性能和复杂度方面的优越性。
