基于改进2D-ESPRIT算法的二维GTD模型参数估计

Parameter Estimation of 2D-GTD Model Based on the Improved 2D-ESPRIT Algorithm

针对经典2D-ESPRIT算法在估计基于几何绕射理论的二维GTD模型参数时受噪声影响较大这一问题,提出了一种改进的2D-ESPRIT算法,有效提高了算法的抗噪性能与参数估计性能。改进算法在经典2D-ESPRIT算法的基础上,首先通过构建交换矩阵,得到含有原始数据Ee共轭信息的另一矩阵Y;其次在通过自相关与互相关处理、叠加取平均,得到新的协方差矩阵R;最后对协方差矩阵解算,估计得到二维GTD模型各参数值。仿真实验表明,改进2D-ESPRIT算法抗噪性能要优于经典2D-ESPRIT算法,在信噪比较低的情况下,改进2D-ESPRIT算法估计得到的模型参数精度更高,性能更稳定。文中还针对其他因素(如矩阵束参数及配对标量β值)对模型参数估计精度的影响进行了探究,为后续仿真实验提供了参考。

The classical 2D-ESPRIT algorithm is sensitive to signal-to-noise-ratio(SNR)when estimating the parameters of two dimensional(2D)geometric theory of diffraction(GTD)model.To solve the problem,an improved 2D-ESPRIT algorithm,which improves the anti-noise performance and parameter estimation performance effectively,was proposed.Firstly,the improved algorithm obtains a new matrix Y containing the conjugate information of the original matrix Ee by constructing an exchange matrix.Secondly,a new covariance matrix R can be obtained by auto-correlation,cross correlation,superposition and average processing.Finally,the parameters of 2D-GTD model can be estimated by calculating the new covariance matrix R.Simulation results show that the improved 2D-ESPRIT algorithm has a better anti-noise performance,and it owns higher estimation precision and more stable performance than the classical 2D-ESPRIT algorithm accurately in the case of low signal-to-noise ratio.The impact of other factors,such as matrix pencil parameters and paring variableβ,on parameter estimation precision was also studied,which can be provide references for future simulations.