基于FFT和迭代插值的改进型超分辨算法

基于单快拍的快速迭代插值DOA（Direction of Arrival）估计方法，有效地消除了频谱泄漏，实现了多源DOA的无偏估计。但是该算法需要提前确定信源的个数，且运算量大，因此在工程应用中受限。本文提出一种新方案，利用传统角度域FFT提供粗略角度估计，然后通过迭代插值法细化角度，最终基于对消残差功率和信息论准则进行信源个数估计。该方案无需预知信源个数，且文中提出的基于残差变化率的收敛策略大大减少了细化估计的迭代次数，从而有效地降低了原算法的计算量。通过仿真结果验证了该方案的有效性，在估计精度及分辨率方面性能接近快速迭代插值波束形成算法，优于子空间类算法。

An Improved Super-Resolution Algorithm Based on FFT and Iterative Interpolation

The fast iterative interpolation DOA (Direction of Arrival) estimation method based on single snapshot effectively eliminates the spectrum leakage and realizes the unbiased estimation of multi-source DOA. However, the algorithm needs to predict the number of sources, and has a large amount of calculation, so it is limited in engineering applications. This paper proposes a new scheme. The algorithm uses traditional angle-domain FFT to provide a rough angle estimate, and then refines the angle by iterative interpolation. Finally, the number of sources is estimated based on the residual power and information theory criteria. The algorithm does not need to predict the number of sources, and the convergence strategy based on the residual change rate proposed in this paper greatly reduces the number of iterations of the refined estimation, thereby effectively reducing the amount of calculation of the original algorithm. The simulation results verify the effectiveness of the proposed scheme. The performance of the scheme is close to the fast iterative interpolation beamforming algorithm in terms of estimation accuracy and resolution, and better than the subspace algorithms.