基于均匀圆阵相干信源的二维DOA估计

随着通信技术的不断发展，信号传输环境变得日益复杂。针对多径传播形成的高度相关和相干信号测向问题，提出了一种基于均匀圆阵相干信源的二维DOA估计方法。该方法利用均匀圆阵轴向虚拟平移解相干，通过去噪后利用虚拟子阵的自协方差矩阵和互协方差矩阵构造波达方向矩阵，利用该矩阵特征分解估计信号的俯仰角；然后将平滑后的自协方差矩阵与波束空间变换矩阵相乘，使圆阵的导向矢量具备范德蒙结构，最后用求根MUSIC算法估计出信号的方位角，完成了相干信号的二维DOA估计。该方法无需二维谱峰搜索，方位角和俯仰角自动配对，计算量小，分辨率高。仿真实验证明了所提方法的正确性。

Two-Dimensional DOA Estimation Based on Uniform Circular Array Coherent Sources

With the development of communication technology, the environment of signal transmission becomes more and more complicated. In order to solve the direction finding problem of highly correlated and cohe-rent signals formed by multipath propagation, a two-dimensional DOA estimation method based on uniform circular array with coherent sources is proposed. The method uses axial virtual transformation of uniform circular array to eliminate the coherence of signals. After noise elimination, the self-covariance matrix and cross-covariance matrix of the virtual subarray are used to construct the DOA matrix. The eigenvalue decomposition of DOA matrix is used to estimate the elevation angle of the signals. Then, the smoothing covariance matrix and the beam space transformation matrix are multiplied directly, which makes the circle of the steering vector to have Vandermonde structure. In the end, the Root-MUSIC algorithm is used to estimate the azimuth angle of the signals to complete the 2-D DOA estimation of coherent signals. Due to no need to search for 2-D spectral peak and automatic matching of azimuth and elevation, this method has small computation and high resolution. Simulation results show the correctness of the proposed method.