Abstract: The noise robustness and parameter estimation performance of the classical three-dimensional estimating signal parameter via rotational invariance techniques (3D-ESPRIT) algorithm are poor when estimating parameters of the three dimensional geometric theory of diffraction(3D-GTD) model at low signal-to-noise ratio (SNR). To solve this problem, a modified algorithm is proposed. The modified algorithm improves the parameter estimation accuracy by constructing conjugated matrix of the original back-scattered data, averaging the covariance matrices and performing quadratic power on the total covariance matrix to get another novel covariance matrix. The modified algorithm can broaden the differences between the eigenvalues of noises and signals, which is equivalent to increase SNR. Based on the parameters estimated by different algorithms, root-mean-square-errors of different parameters can be compared. Simulations verify that the parameter estimation performance and noise robustness of the modified algorithm are better than the classical 3D-ESPRIT algorithm and the improved algorithm without pair.

Key words: parameter estimation, scattering center, three-dimensional geometric theory of diffraction model, three-dimensional estimating signal parameter via rotational invariance techniques