论文标题
使用结构化协方差矩阵恢复和带网格改进的SBL的最大可能性无网状DOA估计
Maximum Likelihood-based Gridless DoA Estimation Using Structured Covariance Matrix Recovery and SBL with Grid Refinement
论文作者
论文摘要
我们考虑在应用程序中使用的参数数据模型,例如线频谱估计和到达方向估计。我们专注于随机最大似然估计(MLE)框架,并提供了以无情的方式估算关注参数的方法,从而克服了过去的模型复杂性。重新聚集目标的现代趋势和利用稀疏的贝叶斯学习(SBL)方法的现代趋势可以实现这一进展。后者被证明是一种相关性的方法,对于基本问题,它被确定为基于网格的技术,用于恢复测量的结构化协方差矩阵。对于当结构化矩阵作为采样的toeplitz矩阵表达的情况,例如,在定期间隔在时间或空间中采样测量时,SBL客观的其他约束和重新聚集会导致基于MLE的提议的结构化基质恢复技术。提出的优化问题是非凸,我们提出了一种基于大型化最小化的迭代程序来估计结构化矩阵。每个迭代都求解一个半决赛程序。我们通过吸引PSD Toeplitz矩阵分解的caratheodory-fejer结果,以无情的方式恢复了感兴趣的参数。对于不规则间隔时间或空间样品的一般情况,我们提出了一种迭代的SBL程序,该程序可以完善网格点以增加潜在源位置附近的分辨率,同时均保持较低的每次迭代复杂性。我们提供了数值结果,以评估和比较所提出的技术的性能与其他无网状技术和CRB。所提出的相关性方法对环境/系统效应(例如快照数量,相关来源,源位置之间的小分离并改善源可识别性的较小分离)更为强大。
We consider the parametric data model employed in applications such as line spectral estimation and direction-of-arrival estimation. We focus on the stochastic maximum likelihood estimation (MLE) framework and offer approaches to estimate the parameter of interest in a gridless manner, overcoming the model complexities of the past. This progress is enabled by the modern trend of reparameterization of the objective and exploiting the sparse Bayesian learning (SBL) approach. The latter is shown to be a correlation-aware method, and for the underlying problem it is identified as a grid-based technique for recovering a structured covariance matrix of the measurements. For the case when the structured matrix is expressible as a sampled Toeplitz matrix, such as when measurements are sampled in time or space at regular intervals, additional constraints and reparameterization of the SBL objective leads to the proposed structured matrix recovery technique based on MLE. The proposed optimization problem is non-convex, and we propose a majorization-minimization based iterative procedure to estimate the structured matrix; each iteration solves a semidefinite program. We recover the parameter of interest in a gridless manner by appealing to the Caratheodory-Fejer result on decomposition of PSD Toeplitz matrices. For the general case of irregularly spaced time or spatial samples, we propose an iterative SBL procedure that refines grid points to increase resolution near potential source locations, while maintaining a low per iteration complexity. We provide numerical results to evaluate and compare the performance of the proposed techniques with other gridless techniques, and the CRB. The proposed correlation-aware approach is more robust to environmental/system effects such as low number of snapshots, correlated sources, small separation between source locations and improves sources identifiability.