A Sparse-Based Off-Grid DOA Estimation Method for Coprime Arrays
College of Information and Communication Engineering, Harbin Engineering University, Harbin 150001, China
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Sensors 2018, 18(9), 3025; https://doi.org/10.3390/s18093025
Received: 25 July 2018
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Revised: 26 August 2018
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Accepted: 3 September 2018
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Published: 10 September 2018
(This article belongs to the Section Physical Sensors)
Recently, many sparse-based direction-of-arrival (DOA) estimation methods for coprime arrays have become popular for their excellent detection performance. However, these methods often suffer from grid mismatch problem due to the discretization of the potential angle space, which will cause DOA estimation performance degradation when the target is off-grid. To this end, we proposed a sparse-based off-grid DOA estimation method for coprime arrays in this paper, which includes two parts: coarse estimation process and fine estimation process. In the coarse estimation process, the grid points closest to the true DOAs, named coarse DOAs, are derived by solving an optimization problem, which is constructed according to the statistical property of the vectorized covariance matrix estimation error. Meanwhile, we eliminate the unknown noise variance effectively through a linear transformation. Due to finite snapshots effect, some undesirable correlation terms between signal and noise vectors exist in the sample covariance matrix. In the fine estimation process, we therefore remove the undesirable correlation terms from the sample covariance matrix first, and then utilize a two-step iterative method to update the grid biases. Combining the coarse DOAs with the grid biases, the final DOAs can be obtained. In the end, simulation results verify the effectiveness of the proposed method.
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Keywords:
DOA estimation; coprime arrays; sparse-based methods; off-grid; grid biases
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MDPI and ACS Style
Si, W.; Zeng, F.; Hou, C.; Peng, Z. A Sparse-Based Off-Grid DOA Estimation Method for Coprime Arrays. Sensors 2018, 18, 3025. https://doi.org/10.3390/s18093025
AMA Style
Si W, Zeng F, Hou C, Peng Z. A Sparse-Based Off-Grid DOA Estimation Method for Coprime Arrays. Sensors. 2018; 18(9):3025. https://doi.org/10.3390/s18093025
Chicago/Turabian StyleSi, Weijian, Fuhong Zeng, Changbo Hou, and Zhanli Peng. 2018. "A Sparse-Based Off-Grid DOA Estimation Method for Coprime Arrays" Sensors 18, no. 9: 3025. https://doi.org/10.3390/s18093025
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