Fast and Accurate Single-Snapshot DOA Estimation: Iterative Interpolated Approaches

Estimating the direction of arrival (DOA) of a single source signal from a single observation of an array data still plays an important part in practical application scenarios. To address the problem, this letter proposes two iterative, fast, and accurate approaches, namely, the Q-shift-based DOA estimation algorithm (QS-DOAEA) and the tradeoff between A&M and Q-shift-based DOA estimation algorithm (TAQ-DOAEA). QS-DOAEA adopts the interpolation of shifted discrete Fourier transform (DFT)coefficients to iteratively obtain the near-optimal estimation. TAQ-DOAEA employs the error function by simultaneously mixing the q-shifted and half-shifted DFT coefficients, which only requires two iterations. Numerical results reveal that QS-DOAEA achieves significant improvement in terms of estimation accuracy and TAQ-DOAEA expedites the convergence. The proposed estimation algorithms demonstrate that they have an asymptotic variance that is at least 1.0013 times the asymptotic Cramer-Rao bound (ACRB), and provide more than 80x reduction in the computational cost, compared to the baseline method. All our proposed algorithms and code are available at https://github.com/jn-z/.