Research On Estimation Method Of Direction Of Arrival Based On Co-prime Array

Array structure is the primary factor affecting direction-of-arrival estimation performance,large array aperture and high degrees of freedom of array has beter spatial resolution.Co-prime array adopts a sparse array structure,which can effectively increase the array aperture,and the virtual array elements generated by the differential joint processing greatly improve the degrees of freedom of the array.Compared with the uniform linear array,the coprime array can obtain an array with a high degrees of freedom and a large aperture with a small number of array elements,which can effectively reduce the cost and achieve high-precision DOA estimation,which has certain practical significance.Therefore,this article is based on the existing co-prime array DOA estimation method to carry out the following research:In order to improve the performance of sparse reconstruction algorithms based on virtual continuous array elements in the case of low snapshots,a sparse reconstruction DOA estimation method based on actual noise estimation and basis pursuit do-nosing is proposed.The spatial smoothing algorithm is used to effectively eliminates the influence of coherent information in the virtual signal.By pre-estimating the actual noise,the prior information of the DOA estimation method is added,and the robustness of the algorithm is improved.The simulation results show that the proposed method can effectively perform DOA estimation when the number of sources is greater than the number of array elements,enhance the interference suppression effect in non-source angle regions,and has good parameter estimation performance in the case of low snapshots.Aiming at the problem of holes in virtual array,put forward a kind of based on weighted truncated nuclear norm of covariance matrix reconstruction for DOA estimation method.Using the truncated nuclear norm constraint to realize the completion of virtual array elements has more acctcurate parameter estimation performance than the matrix completion algorithm based on nuclear norm.Considering that the number of holes in each row of the matrix to be completed is different,the method of weighting processing is introduced into the process of matrix completing.The estimation accuracy and convergence rate of the algorithm are improved,and the direction of each source can be effectively estimated at the same time as the accurate completion is completed.The simulation results show that,the proposed method has a fast convergence speed,high DOA estimation accuracy,and can accurately distinguish the source direction with a small difference between adjacent angles.