Noncircular DOA estimation algorithm via propagator method and euler transformation

摘要

We mainly consider the direction of arrival (DOA) estimation of noncircular (NC) signal for uniform linear array in this paper. A computationally efficient noncircular real-valued DOA Estimation algorithm based on Euler transformation and propagator method (NC-Euler-PM) is proposed. The proposed algorithm, which avoids spectral peak searching process and eigenvalue decomposition, can achieve closed-form solution of DOAs by utilizing the rotational invariance (RI) property. In this work, the key idea is to construct a real-valued extended array output via Euler transformation, thus the arithmetic of the proposed algorithm is converted from complex field to real field. The proposed NC-Euler-PM algorithm has a lower computational complexity than that of NC-RI-PM algorithm, NC-ESPRIT algorithm and Improved NC-RI-PM algorithm. The angle estimation performance of the proposed algorithm is better than that of the conventional PM algorithm and close to that of Improved NC-RI-PM algorithm. Particularly, due to the extended real-valued propagator matrix in the proposed algorithm, the proposed NC-Euler-PM algorithm has better angle estimation performance than Improved NC-RI-PM algorithm in lower signal-to-noise ratio (SNR). The maximum number of signals estimated by the proposed algorithm is two times of that of the conventional PM algorithm by exploiting the non-circularity. The estimation error and Cramer-Rao bound (CRB) of noncircular signals for uniform linear array are also derived. Simulation results are presented to demonstrate the effectiveness of the proposed algorithm.