Research On DOA Estimation Algorithm Under Mutual Coupling Effect

Direction of arrival(DOA)estimation is an important research branch of array signal processing,it has developed rapidly over the past half century with applications in a wide range of fields,including radar,communications,sonar,and conferencing systems.In the real environment,there are reflections on mountains and urban buildings owning to stereoscopic effects,and artificial electromagnetic interference at military installations.,the signal arriving at the array antenna presents a coherent signal nature.At the same time,most of the existing DOA estimation algorithms require the array manifold to be precisely known,but in practice,influenced by a variety of errors(such as array element amplitude phase error,array element position error,mutual coupling error),the ideal array manifold will be deviated or perturbed,and if the algorithm is not corrected,it will lead to the algorithm estimation performance degradation and serious failure.Therefore,in this paper,we focus on the coexistence of independent and coherent signals in the case of mutual coupling,focusing on the operational complexity,efficiency and estimation accuracy of the algorithm,the strengths and weaknesses of existing algorithms will be analyzed,followed by specific improvements.The effectiveness of the proposed algorithm will be analyzed.A Decoupling L-shaped Array Based on ESPRIT(L-DC-ESPRIT)algorithm is proposed to implement the decoupling self-correction of L-shaped array antennas and the 2D DOA estimation of the incident sources.It reduces the complexity of the algorithm by constructing a reasonable selection matrix to reconstruct the received signal and avoiding the cascade estimation of the mutual coupling coefficients and the 2D DOA of the signal.This algorithm is in L-shaped array antenna.The mutual coupling coefficients and the matrix of guided realization stripping are pushed to the new receiving matrix,and the new receiving matrix is used to construct the subarray that throws the rotation invariant relationship under the mutual coupling effect,and the simulation results verify the mutual coupling self-correction capability and estimation performance of the algorithm.A mutual coupling and decoherence correction algorithm is proposed to achieve DOA estimation of coherent signals in homogeneous linear arrays where mutual coupling exists.By using the Toeplitz property of the mutual coupling matrix and the auxiliary array element method,an array reception model is constructed in which the guidance vector is not affected by the mutual coupling matrix,and then a full-rank Toeplitz is constructed for decoherence to achieve the DOA estimation of coherent signals under mutual coupling.The DOA estimation algorithm based on the L-shaped array DOA estimation on the basis of mutual coupling and the DOA estimation algorithm on the basis of the coexistence of independent and coherent signals in the case of mutual coupling are proposed with the objectives of reducing the complexity of the algorithm and improving the directional accuracy by mutual coupling self-correction.