Research On Performance Promotion Of Parameter Estimation Based On Polarization Sensitive Array Via Compressed Sensing

Compared with scalar arrays, polarization sensitive arrays possess more dimensions of estimation and thus promoted the output performance including parameter estimation through utilizing spatial information and polarization information synchronously, which attracts increasing interest of research in the field of array signal processing. Conventional methods of joint polarization-space spectrum estimation realize estimation of DOA(Direction Of Arrival) including elevation and azimuth and polarization state including auxiliary polarization angle and polarization phase difference under the exploitation of certain rotational invariance in polarization or space. However, the existence of amplitude and phase error would spoil the rotational invariance incurring the decline of performance of parameter estimation and even the ineffectiveness of estimation. Targeted at this problem, we attempted to exploit the compressed sensing methods to promote the performance of parameter estimation under the circumstance of existing amplitude and phase error in addition of less hardware cost and algorithm complexity. Herein, the author performs the study of methods on promoting performance of parameter estimations in polarization sensitive array via compressed sensing in this thesis.Based on the array manifold consisting of single vector-sensor and Z-axis polarized plane array, VS-OMP(Vector-Sensor Orthogonal Matching Pursuit) is proposed corresponding to the insufficient accuracy of parameter estimation of vector-sensor. Firstly, an initial parameter estimation of DOA and polarization is executed in utilization of received data of single vector-sensor at origin. A combinatorial dictionary of several local dictionaries with the centers of the aforementioned result and radii limited by the range of error is then generated. Since then, we’re able to perform a further estimation of DOA which results in higher accuracy. The outcome of simulations testified the validity of the method and suggested that VS-OMP holds a equally matched performance of ESPRIT(Estimation of Signal Parameter via Rotational Invariance Techniques) methods. Nevertheless, performance of both methods decreases in the case of coexistence of strong and weak sources.In response to the issue combined with amplitude and phase error, a stable compressed sensing based method depended on trebly orthogonally polarized array is proposed, which is capable of separating strong and weak sources. The method employs OMP method to acquire the average of three groups of DOA estimation according to three sets of received data obtained through three orthogonally electro-polarized arrays as commencement. Subsequently, a shape-preserving nullifying scheme amplifies weak sources and suppresses strong sources while maintaining the polarization information undistorted. Eventually, the estimation of polarization is acquired from unitized electronic vectors. Compared with conventional methods, the proposed method promotes the performance of parameter estimation of polarization sensitive array. Furthermore, it’s suitable for parameter estimation of coherent sources without extra processing schemes.Overall, research of the thesis indicates that utilization of compressed sensing methods improves the performance of parameter estimation of polarization sensitive array under circumstance of coherent sources and existence of amplitude and phase error in comparison with ESPRIT-based methods of joint polarization-space spectrum estimation.