On the virtual array concept for the fourth-order direction finding problem

1999 ◽  
Vol 47 (9) ◽  
pp. 2592-2595 ◽  
Author(s):  
P. Chevalier ◽  
A. Ferreol
Keyword(s):  
Fourth Order ◽  
Direction Finding ◽  
Virtual Array

scholarly journals An Effective Technique for Enhancing Direction Finding Performance of Virtual Arrays

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Wenxing Li ◽  
Xiaojun Mao ◽  
Wenhua Yu ◽  
Chongyi Yue
Keyword(s):  
Antenna Array ◽  
Interpolation Method ◽  
Doa Estimation ◽  
Direction Finding ◽  
Estimation Accuracy ◽  
Signal Subspace ◽  
Effective Technique ◽  
Resolution Capability ◽  
Significant Bias ◽  
Virtual Array

The array interpolation technology that is used to establish a virtual array from a real antenna array is widely used in direction finding. The traditional interpolation transformation technology causes significant bias in the directional-of-arrival (DOA) estimation due to its transform errors. In this paper, we proposed a modified interpolation method that significantly reduces bias in the DOA estimation of a virtual antenna array and improves the resolution capability. Using the projection concept, this paper projects the transformation matrix into the real array data covariance matrix; the operation not only enhances the signal subspace but also improves the orthogonality between the signal and noise subspace. Numerical results demonstrate the effectiveness of the proposed method. The proposed method can achieve better DOA estimation accuracy of virtual arrays and has a high resolution performance compared to the traditional interpolation method.

scholarly journals Thinned Virtual Array for Cramer Rao Bound Optimization in MIMO Radar

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xia Li ◽  
Buhong Wang
Keyword(s):  
Performance Indicator ◽  
Multiple Input Multiple Output ◽  
Doa Estimation ◽  
Direction Finding ◽  
Mimo Radar ◽  
Combinatorial Problems ◽  
Array Configuration ◽  
Virtual Array ◽  
Array Aperture ◽  
Cramer Rao Bound

By transmitting multiple independent waveforms at the transmit side and processing echoes of spatial targets at the receive side, Multiple Input Multiple Output (MIMO) radar enjoys virtual array aperture expansion and more degree of freedom (DOF), both of which favors the application of direction finding or estimation of direction of arrival (DOA). The expanded virtual aperture provides higher angular resolution which also promotes the precision of DOA estimation, and the extra DOF brought by waveform diversity can be leveraged to focus energy in certain spatial region for better direction-finding capacity. However, beamspace methods which match certain beampatterns suffer from deteriorated performance and complexity in implementation, and the advantage of virtual array aperture is limited by its virtual element redundancy. As an important performance indicator of DOA estimation, Cramer–Rao Bound (CRB) is closely connected to the array configuration of the system. To reduce the complexity of the system and improve CRB performance at the same time, in this paper, the virtual array of MIMO radar is designed directly by selecting outputs from matched filters at the receive side. For the sake of fair comparison, both scenarios with and without priori directions are considered to obtain optimized virtual array configuration, respectively. The original combinatorial problems are approximated by sequential convex approximations methods which produce solutions with efficiency. Numerical results demonstrate that the proposed method can provide thinned virtual arrays with excellent CRB performance.

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