Research On Joint DOA And Polarization Estimation Algorithm For Vector Sensor Arrays

Polarization of electromagnetic wave is an important signal parameter information in signal processing. The diversity of polarization selection feature of the vector sensor array elements enables the array to observation signal wave field in vector way, thus we are able to extract more detailed microscopic structure information. Therefore, vector sensor array has broad application prospects in radar,communication,seismic exploration, radio astronomy,medical imaging and other high-tech fields. The extraction and rational use of polarization information of electromagnetic wave can improve the recognition capability of radar and decoy, which is beneficial to improving the whole performance of communication system.This paper studies the joint Direction Of Arrival (DOA) and polarization parameter estimation with vector sensor array and the main content of this paper can be summarized as the following aspects:The first part studies the basic theoretical knowledge of the polarization of electromagnetic wave and the structure of vector sensor array. Firstly,the mathematical expression of electromagnetic wave is studied, and by mathematical features the electromagnetic wave can be divided into fully polarized or partially polarized wave, and then the connection between them is discovered. Secondly, the space model and the mathematical representation of vector sensor array are introduced and the classification of vector sensor array is presented. Finally, the signal model assumption is given based on the main content of the paper and the signal receiving model of vector sensor array is set up.The second part studies the signal receiving model of six dimensional electromagnetic vector sensor array and the estimation of joint DOA and polarization parameters. Firstly, the signal receiving model of electromagnetic vector sensor array is presented and Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) algorithm is utilized to get frequency of the signal and the steering vector matrix, then with the vector-cross-product method peculiarly in electromagnetic vector sensor the DOA and polarization information is obtained. Secondly, in order to get higher precision of signal DOA information and reduce the mutual coupling influence between array elements, the spatially spread electromagnetic vector sensor is given, then interferometer method is adopted to get the signals' periodic ambiguous but high accuracy DO A estimation and with the coarse DOA estimation obtained by vector-cross-product method the high accuracy DOA information is received. Finally, the simulation results verify the validity of the methods.The third part studies the joint estimation of DOA and polarization parameters of the L shaped incomplete vector sensor array. Firstly, two kinds of L shaped array are putting forward,one is a non-uniform L shaped sparse array consisting of loops and dipoles,the other is a uniform L shaped sparse array composed of only dipoles. The high precision DOA information is calculated by using ESPRIT algorithm, polarization diversity reception theory,phase interferometer method, etc. Secondly, compared with the two kinds of L shaped sparse array, the second one has less computation. Finally, the simulation results verify the feasibility of the algorithm. In this paper,the adjacent array elements' spacing of the proposed array is beyond half wavelength of the signal, thus the array extends the two-dimensional physical aperture and reduces the mutual coupling effects to a degree. Both of the L shaped array has scalability and correspondingly signal DOA estimation accuracy is greatly improved.