Single-Snapshot Gridless 2D-DoA Estimation for UCAs: A Joint Optimization Approach
Salar Nouri
TL;DR
This work addresses single-snapshot gridless 2D-DOA estimation for Uniform Circular Arrays by formulating a unified optimization that jointly designs a data-adaptive transformation $\mathbf{T}$ and estimates azimuth-elevation pairs $(\theta_k,\phi_k)$. An iALM-based solver avoids SDP by reformulating the atomic norm via a Burer–Monteiro factorization and enforcing semi-infinite manifold constraints through a tractable CAD-like structure, solved with block coordinate descent. The method demonstrates superior accuracy and resolution in simulations against 2D-MUSIC and grid-based Lasso, while maintaining practical runtimes, particularly in challenging low-SNR and closely spaced-source scenarios. The JADE approach offers a robust, gridless framework for single-shot array processing, with potential extensions to other geometries and wider bandwidths.
Abstract
This paper tackles the challenging problem of gridless two-dimensional (2D) direction-of-arrival (DOA) estimation for a uniform circular array (UCA) from a single snapshot of data. Conventional gridless methods often fail in this scenario due to prohibitive computational costs or a lack of robustness. We propose a novel framework that overcomes these limitations by jointly estimating a manifold transformation matrix and the source azimuth-elevation pairs within a single, unified optimization problem. This problem is solved efficiently using an inexact Augmented Lagrangian Method (iALM), which completely circumvents the need for semidefinite programming. By unifying the objectives of data fidelity and transformation robustness, our approach is uniquely suited for the demanding single-snapshot case. Simulation results confirm that the proposed iALM framework provides robust and high-resolution, gridless 2D-DOA estimates, establishing its efficacy for challenging array signal processing applications.
