Coherent Signal DOA Estimation for MIMO Radar under Composite Background of Strong Interference and Non-Uniform Noise

Abstract

To address the problems of low accuracy and low robustness of the conventional algorithm in estimating the direction of arrival (DOA) of coherent signals against a composite background of strong interference and non-uniform noise, in this paper, a coherent signal DOA estimation algorithm based on fixed projection blocking is proposed in conjunction with a multi-input multi-output (MIMO) radar. The covariance matrix of the received signal is first decomposed by eigenvalues, and a fixed projection matrix orthogonal to the interference guidance vector is constructed as the interference blocking matrix. Then, the received array signal is pre-processed to re-form the covariance matrix, and this matrix is rendered decoherent through a Toeplitz reconstruction. Finally, the reconstructed covariance matrix is estimated by DOA using the propagation operator algorithm to reduce the complexity. The simulation verifies that the proposed algorithm has a better robustness and higher accuracy than conventional algorithms for the DOA estimation of coherent signals in composite backgrounds.

Multi-dimensional parameter estimation of uniform circular array electromagnetic vector sensor based on polarization-direction of arrival matrix

“…; t e m p : i n t r a l i n k -; e 0 1 0 ; 1 1 7 ; 3 5 3 R ðiÞ X 0 X ¼ Aðθ; φ; γ; ηÞΦ ðiþ1Þ ðφÞR S ðΦ ðiÞ ðφÞÞ H A H ðθ; φ; γ; ηÞ þ σ 2 I; (10) where 0 ≤ i ≤ ðP − 1Þ and R S ¼ SðtÞS H ðtÞ in Eqs. ( 9) and (10). Since the incoming signal is coherent, R S is a singular matrix.…”

“…Step 2 Calculate the auto-covariance matrix R ðiÞ XX of each translation subarray and the crosscovariance matrix R ðiÞ X 0 X between adjacent subarrays by Eqs. ( 9) and (10).…”

“…Electromagnetic vector sensor (EVS), 8 which can not only provide the spatial orientation information of electromagnetic waves but also receive the polarization information, has gained huge success in the field of radar array signal processing 9 – 11 The uniform circular array is a kind of planar array, which can meet the requirements of omni-directional and unambiguous angle estimation, and it is easier to keep conformal with the carrier, so it is often used as one of the passive array antennas 12 . In view of the unique advantages of UCA and EVS, it is of great and practical significance to study the joint estimation method of polarization and DOA parameters of arrays composed of UCA and EVS.…”