Modified UCA-ESPRIT for Estimating DOA of Coherent Signals using One Snapshot

This paper introduces a modified UCA- ESPRIT algorithm to estimate the direction of arrival (DOA) of coherent signals using one single snapshot. First, the mode excitation method is used to transform the uniform circular array (UCA) in element space into a virtual uniform linear array (VULA) in mode space. Then, the Hermitian Toeplitz matrix can be reconstructed from the observed data vector as a decorrelated algorithm. The purpose for using the Hermitian Toeplitz matrix is to rearrange the data in order to extend the dimensionality of the noise space. Consequently, signal and noise spaces can be estimated more accurately. The proposed method does not need forward/backward spatial smoothing of the covariance matrix, which would result in reduced computational complexity. Simulation results verify that the proposed algorithm with one snapshot has a close performance to the conventional mode of spatial smoothing with 100 snapshots.