Error Correction And DOA Estimation Of Uniform Linear Array Based On Coherent Distribution Source Model

In the field of array signal processing,the direction of arrival(DOA)estimation has always been a key research topic,and it is also one of the important tasks in the fields of radar,sonar,mobile communications,and biomedical systems.Most of the existing algorithms are based on the point source model,but in practice,the signal propagation is often affected by multi-pass transmission,etc.,resulting in a distributed characteristic of the signal.Under this condition,the DOA estimation algorithm based on the point source model will cause performance degradation or even failure due to the model mismatch problem.It is necessary and necessary to develop DOA estimation methods based on distributed source models.At present,DOA estimation methods based on distributed sources have two common problems or challenges: Most of the existing distributed source DOA estimation algorithms are based on ideal array manifolds.When the array has gain-phase errors,coupling and other array model errors,it's the performance degradation is often very large,and it is difficult to guarantee the positioning accuracy requirements;Most of the existing DOA estimation algorithms based on distributed sources require multi-dimensional search,which is relatively complex and difficult to meet the real-time requirements of the positioning system.In order to overcome the above two common problems,this paper uses the propagation operator algorithm and the disturbance sparse reconstruction method to carry out innovative research under the coherent distributed source model.The main research work and innovation points are summarized as follows:Firstly,based on the theory of spatial spectrum estimation,this paper studies the characteristics of coherent distributed source model and array amplitude and phase error model,and deeply analyzes and deduces two typical DOA estimation algorithms based on coherent distributed source model,and carries out simulation analysis to evaluate the algorithm performance.At the same time,it is found that the estimation performance of the algorithm is seriously degraded under the condition of amplitude and phase error.Secondly,a new method of DOA estimation for coherent distributed sources based on the propagation operator algorithm is proposed based on the condition of the array amplitude and phase error.This method uses the matrix element relationship to realize the amplitude and phase error correction of the array.Finally,the DOA estimation is carried out by constructing a propagation operator.The simulation experiment is compared with the existing algorithm and it is found that the algorithm has better estimation performance and stability,and the algorithm the spectrum peak search and eigenvalue decomposition are avoided,and the algorithm complexity is lower.Finally,a new algorithm for DOA estimation of coherent distributed sources based on perturbation sparse reconstruction is proposed.Firstly,a norm is constructed in the framework of sparse reconstruction,and then the problem is solved by combining truncation function,cost function and iterative strategy.Finally,the parameter estimation is realized by outputting sparse vector and sparse disturbance.Simulation results show the effectiveness of the algorithm.This algorithm can not only successfully estimate DOA when circular signal and non-circular signal coexist,but also accurately estimate source type,source number and signal power.