Simultaneous Source Localization And Polarization Estimation With Spatially Spread Dipole Array

Array signal processing based on electric-magnetic vector sensor array, as an important branch of signal processing, is the hot topic of academic research. Since the EMVS can sense the polarization characteristics of the electromagnetic wave, take advantage of the time-space-polarization multi-dimensional structure of the array, the EMVS has the outstanding performance in DOA and polarization estimation. But the antennas of the standard EMVS are collocated in a common point, which will induce strong mutual coupling effects. Meanwhile, it's hard and expensive to implement, which restrict its application in practical engineering. Non-collocated EMVS, that is spatially stretch electromagnetic vector sensor (SS-EMVS), because of its relatively weak coupling and improved antenna aperture, is receiving more attention. Nonetheless, the existing SS-EMVS requires all the six orthogonal electric-dipoles and magnetic-loops, which not only has complicated structure, but also has the problem that electric-field response and magnetic-field response are often inconsistent in practical applications. Accordingly the performance degradation caused also proposed a new issue, namely whether the parameter estimation can only use electric information or only magnetic information. Based on the above considerations, this paper constructs two types of spatially stretched dipole arrays which consist of only electric dipoles or only small magnetic loops. And the corresponding DOA and polarization estimation scheme based on vector cross-product is proposed. Simultaneously, the Cramer-Rao bounds of the parameter estimates are provided. In addition, a novel near-field source localization based on the Coupled Tensor Decomposition (CCPD) using the proposed spatially stretch dipole array is proposed. The main contributions of this paper are summarized as follows:· Two types of spatially stretched dipole arrays are proposed:the spatially stretched quad dipole (SS-Quad) and spatially stretched quint dipole (SS-Quint) consist of non-collocated four or five dipoles respectively, which could reduce the mutual coupling between antennas, expand the array aperture, and avoid the problem of inconsistence of electric and magnetic response. More importantly, the arrays also satisfy the structure for vector cross product. Furthermore, this paper puts forward the corresponding DOA and polarization estimation scheme based on vector cross-product and optimization method. Besides, the Cramer-Rao bounds (CRB) of the parameter estimates are provided to theoretically analyze the performance of the array. At last, the simulation experiments are conducted to verify the proposed method.· A novel near-field source localization based on the Coupled Tensor Decomposition (CCPD) using the proposed spatially stretch dipole array is proposed. The method can effectively target multiple near-field sources anywhere in three-dimensional space. Interestingly, the array structure can be set arbitrarily, which has more practical significance. More importantly, we break down the traditional near-field source localization problem into several far-field source DOA estimation sub-problems, introduce the multi-set thinking, and apply the Coupled Tensor Decomposition (CCPD) algorithm to restore the steering vector matrix. The CCPD algorithm can improve the accuracy of source separation and has the property of auto permutation alignment. Also, it could deal with the situation that the source signals received by different senor are only correlated while the other single-set methods can't solve. Finally, the simulation experiments validate the performance of proposed method, and show the advantage of localization scheme based on CCPD compared with single-set method.