Research On Mutual Coupling Array Direction Finding Algorithm And System

Array direction finding,also spatial spectrum estimation,is mainly used to determine the spatial position and the characteristic parameters of the signal.It is an important research content in the field of array signal processing.Many high-resolution direction finding algorithms have emerged over the past few decades,most of which are based on accurate array steering matrix.There will always be errors in the actual array direction finding system,in this case,the performance of the algorithm will be seriously degraded.Therefore,it is essential to study the array error correction technology with mutual coupling and the actual array direction finding system.This paper focuses on the sparse spatial spectrum reconstruction problem in the presence of mutual coupling.The uniform linear array direction finding method based on sparse spatial spectrum reconstruction is analyzed at first,and the application of sparse representation theory in mutual coupling correction problem is studied in the case of mutual coupling of array.Considering the structural characteristics of the array steering vector under the mutual coupling effect,the proposed algorithm reconstructs the mutual coupling array flow pattern and the sparse spatial spectrum to be estimated,and transforms the non-convex mathematical model into a convex optimization problem with the optimal solution,which avoids the reduction of the array aperture.Simulation results show that the proposed direction finding algorithm has better performance than some existing methods.In addition,this paper studies array direction finding systems based on the general software radio platform.A portable universal four-element array direction finding system is built based on the array direction finding technology and the characteristics of hardware platform,and the hardware configuration and software flow also are designed.The built system can perform practical engineering direction finding via the subspace method,and can easily transplant other direction finding algorithms to the system.The platform is capable of processing array data in real time online,and the experimental results also show the practicability and versatility of the built system.