Super-Resolution DOA Estimation for Arbitrary Array Geometries Using a Single Noisy Snapshot

We address the problem of search-free DOA estimation from a single noisy snapshot for sensor arrays of arbitrary geometry, by extending a method of gridless super-resolution beamforming to arbitrary arrays with noisy measurements. The primal atomic norm minimization problem is converted to a dual problem in which the periodic dual function is represented with a trigonometric polynomial using truncated Fourier series. The number of terms required for accurate representation depends linearly on the distance of the farthest sensor from a reference. The dual problem is then expressed as a semidefinite program and solved in polynomial time. DOA estimates are obtained via polynomial rooting followed by a LASSO based approach to remove extraneous roots arising in root finding from noisy data, and then source amplitudes are recovered by least squares. Simulations using circular and random planar arrays show high resolution DOA estimation in white and colored noise scenarios.Comment: To appear in Proc. ICASSP 2019, May 12-17, 2019, Brighton, UK. arXiv admin note: substantial text overlap with arXiv:1810.0001

Gridless DOA Estimation and Root-MUSIC for Non-Uniform Arrays

The problem of gridless direction of arrival (DOA) estimation is addressed in the non-uniform array (NUA) case. Traditionally, gridless DOA estimation and root-MUSIC are only applicable for measurements from a uniform linear array (ULA). This is because the sample covariance matrix of ULA measurements has Toeplitz structure, and both algorithms are based on the Vandermonde decomposition of a Toeplitz matrix. The Vandermonde decomposition breaks a Toeplitz matrix into its harmonic components, from which the DOAs are estimated. First, we present the `irregular' Toeplitz matrix and irregular Vandermonde decomposition (IVD), which generalizes the Vandermonde decomposition to apply to a more general set of matrices. It is shown that the IVD is related to the MUSIC and root-MUSIC algorithms. Next, gridless DOA is generalized to the NUA case using IVD. The resulting non-convex optimization problem is solved using alternating projections (AP). A numerical analysis is performed on the AP based solution which shows that the generalization to NUAs has similar performance to traditional gridless DOA