| Compared with the traditional scalar array,the polarization sensitive array composed of vector sensors can obtain and utilize polarization information,so that the direction finding system has better anti-phase ambiguity ability,anti-jamming ability and estimation accuracy.After years of research by scholars at home and abroad,many classical spatial spectrum estimation algorithms have been successfully transplanted into the polarization sensitive array,but such algorithms require an ideal array manifold as a prerequisite.In the actual direction finding system,the array amplitude and phase error caused by the disturbance of the position of the array element,the error of the antenna pattern and the inconsistency of the electromagnetic characteristics of each channel,and the mutual coupling effect between the array elements will lead to the decrease of the accuracy of the algorithm.Therefore,this paper models and analyzes the amplitude and phase errors and mutual coupling errors existing in the polarization array,and proposes a corresponding error correction algorithm to realize the joint estimation of signal parameters and error coefficients.The main research contents are as follows:Aiming at the problem of mutual coupling error between array elements,the uniform circular array is modeled and analyzed,and on the basis of the Rank Deficiency Multiple Signal Classification(RD-MUSIC)algorithm,an algorithm of the mutual coupling error cascade estimation based on modulus constraint is proposed.Firstly,the complex symmetric banded Toeplitz property of the uniform circular array mutual coupling error matrix is used to transform the matrix;then based on the rank deficiency principle of the matrix,the signal parameters are separated from the unknown mutual coupling coefficients,and the signal parameters are obtained by two spectral peak searches;Finally,the mutual coupling coefficient is estimated through the modulus constraint condition.By screening the transition matrix,the proposed algorithm solves the problem of low estimation accuracy of the mutual coupling coefficient in the direction finding environment with low signal to noise ratio and small number of snapshots.Simulation results verify that the proposed algorithm can achieve high-precision estimation of signal parameters and mutual coupling coefficients,and significantly reduce computational complexity.Aiming at the problem of array amplitude and phase error in actual direction finding,the uniform linear array and two-dimensional L array are modeled and analyzed respectively,and a joint estimation algorithm of amplitude and phase error and signal parameters based on the least square method is proposed.Using the rotation-invariant characteristics between sub-arrays,combined with the idea of least squares method for mathematical derivation;through the auxiliary array elements with consistent amplitude and phase characteristics,the problem of minimizing the target is transformed into an optimization problem under linear constraints,and then the amplitude and phase error coefficients of the array are obtained;finally,the direction of arrival(DOA)estimation and polarization parameters of the incident signal are obtained.This algorithm can realize the simultaneous estimation of signal parameters and the amplitude and phase error coefficients when multiple sources are incident,and does not need to perform multi-dimensional spectral peak search,loop iterative operations,and the selection of convergence thresholds,which greatly reduces the amount of calculation and storage.It can meet the real-time requirements in actual engineering.Simulation results verify the effectiveness of the proposed algorithm. |
