Research On Direction Detection Technology Based On Polarization Sensitive Array

Radio technology has developed rapidly in recent years,and the polarization information of the antenna is a very useful radio resource for subsequent signal processing.Polarization-sensitive arrays can not only receive the basic information of the signal but also obtain the polarization information of the signal because of its special array structure.Therefore,polarization-sensitive arrays have become one of the most popular research topics in direction detection in recent years.However,most of the polarization-sensitive array direction detection systems are directly extended from the existing spatial spectrum estimation algorithm and source number estimation algorithm in the regular array.The special array structure of the polarization-sensitive array is not used,and the estimation performance of the directly extended application algorithm needs to be improved.In this thesis,we conducted the following research on the special structure of polarization sensitive arrays:Firstly,we constructed the Polarization Sensitive Array Received Signal Model.We also analyzed the current Source Number Estimation Algorithm for Polarization Sensitive Array and Joint estimation algorithm for DOA and polarization parameters of polarization sensitive arrays,showing the advantage and disadvantage of them as well as improving them.Secondly,it's essential to ensure the accuracy of direction detection by improving the accuracy of estimation of source number.In practical applications,the performance of the estimation of source number is influenced by the background noise.With the background of color noise,most current source number estimation algorithms produces significant error,sometimes even failure.Aiming at the above defects,we proposed a Source number estimation algorithm which can be applied in color noise environment.We constructed a projection matrix using signal subspace and noise subspace,and then projected the data covariance matrix.Finally,we obtained the number of sources from the discriminant function constructed on top of the pervious results.Then,while doing joint estimation of DOA and polarization parameters for polarization-sensitive arrays based on long vector-based MUSIC algorithm,fourdimensional peak search operation is required,which causes the computational overhead.In order to solve this problem better,a dimensionally reduced MUSIC algorithm based on polarization-sensitive array symmetric interval search is proposed.The algorithm firstly reduces the dimension of the polarization parameter information in the polarization sensitive array receiving matrix to reduce the search dimension.Then,according to the phase characteristics of the polarization sensitive array,the search range is symmetry,and the whole spectrum is completed with half of the search interval.Finally,the entire direction detection system was simulated on the GNU Radio software platform.We combined the two proposed algorithms by leveraging the GNU Radio software platform,to simulate the complete polarization sensitive array direction detection system with the signal module,algorithm module,and display module involved and test the whole system.The direction detection algorithm based on polarization sensitive array that are designed in this thesis enables quick detection at the needed position when the ground radar and the early warning aircraft are completely in adequate.It plays a very important role in both daily life and on the battlefield.