Quadratic Forward/Backward Spatial Smoothing Polarization Smoothing MUSIC algorithm for Low Angle Estimation
Jun Tan, Zaiping Nie, Shan Peng · 2019
The Polarization Smoothing is a benchmark algorithm to wipe off the coherence of the multipath signals for low angle estimation problem though the difference of the reflection coefficients between the vertical and horizontal polarizations. However, when the elevation angle of the target is close to zero, there is little difference for the Fresnel reflection coefficients between the horizontal and vertical polarizations, which leads to poor decorrelation performance and poor low angle estimation performance. In order to solve this problem, the Quadratic Forward/Backward spatial smoothing Polarization Smoothing MUSIC (QFB-PS-MUSIC) algorithm is proposed in this paper. The proposed algorithm takes advantage of the Quadratic technique, Forward/Backward spatial smoothing and Polarization Smoothing simultaneously to improve the low angle estimation performance, especially when the arrival angle of the direct signals and the specular signals are closely spaced. The proposed method has better performance for low angle estimation compared with PS-MUSIC and PS-FB-MUSIC. And the simulation results are presented to verify the effectiveness of the proposed method.