基于联合稀疏恢复的可编程超表面离网格DOA估计方法

      Off-Grid DOA Estimation Method Based on Joint Sparse Recovery Using Programmable Metasurface

      • 摘要: 波达方向(Direction of Arrival, DOA)估计是阵列信号处理的关键技术之一。基于可编程超表面的DOA估计方法能够有效降低系统成本与复杂度,但现有典型方法的性能受空间离散化所导致网格失配的影响。针对该问题,本文提出了基于联合稀疏恢复的可编程超表面离网格DOA估计方法。首先,基于泰勒展开构建了同时包含网格项与导数项的联合过完备字典,建立了一维联合DOA估计模型。在此基础上,将该模型拓展至二维场景,以实现方位角与俯仰角的同时高精度估计。为降低二维模型的计算复杂度,进一步提出了基于Kronecker分解的模型简化方法,将高维运算转化为低维运算。为对所构建的模型进行求解,本文提出了联合正交匹配追踪和联合<italic>L</italic>1范数最小化稀疏恢复方法。仿真与实测结果表明,相比现有典型方法,所提方法能够提高超表面的DOA估计精度。同时,基于Kronecker分解的简化模型在保持与原模型相近精度的前提下,显著降低了计算复杂度。

         

        Abstract: Direction of Arrival (DOA) estimation is a core technique in array signal processing. Although sparse recovery-based DOA estimation methods using programmable metasurfaces can effectively reduce system cost and complexity, their performance is affected by the grid mismatch caused by spatial discretization. To address this issue, this paper proposes the off-grid DOA estimation methods for programmable metasurfaces based on joint sparse recovery. Firstly, a joint overcomplete dictionary containing both grid-term and derivative-term is constructed based on the Taylor expansion, thereby establishing a one-dimensional joint DOA estimation model. Building upon this, the model is extended to a two-dimensional scenario, achieving off-grid estimation of both azimuth and elevation angles. To reduce the computational complexity of the two-dimensional model, a model simplification method based on Kronecker decomposition is further introduced, transforming high-dimensional operations into lower-dimensional ones. To solve the formulated models, this paper proposes two joint sparse recovery algorithms, namely Joint Orthogonal Matching Pursuit and Joint L1-norm minimization. Simulation and practical measurement results demonstrate that the proposed method improves the DOA estimation accuracy of metasurfaces compared to existing typical methods. Meanwhile, the simplified model based on Kronecker decomposition reduces computational complexity while maintaining accuracy comparable to the original model.

         

      /

      返回文章
      返回