A Virtual Space-Time Adaptive Beamforming Method for Space-Time Antijamming

Self Cite

Most of space-time adaptive processing methods have the excellent ability to suppress interferences when the space-time covariance matrix is perfectly estimated. Unfortunately, these methods may have calculation error of the covariance matrix in the case of fewer snapshots, which may lead to remarkable performance degrading. To solve the aforementioned problem, a space-frequency domain anti-jamming algorithm based on the compressed sensing theory (CS-SFD) is presented. Firstly, the proposed method utilizes less sampled data to form a space-frequency two-dimensional sparse representation for the narrowband interference signals. Secondly, the interference covariance matrix estimation problem is modeled as a sparse reconstruction problem which can be efficiently solved by the orthogonal matching pursuit algorithm. Furthermore, the diagonal loading method is used to modify the interference plus noise covariance matrix. Finally, the weight vector is given by the minimum output power criterion. Compared with the previous work, the presented method has better robustness and more effectively anti-jamming performance in the case of fewer snapshots. Simulation results show the effectiveness of the proposed algorithm.

“…x = Φg + n (7) where n is the noise vector. Φ, formed by space-time steering vectors, is the basic matrix whose dimension is MN × N d N f .…”

Section: Covariance Matrix Recoverymentioning

confidence: 99%

Section: Covariance Matrix Recoverymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Cs-SFD Algorithm for GNSS Anti-Jamming Receivers

Liu¹,

Liu²,

Yang³

et al. 2019

Self Cite

“…The LMS algorithm is an adaptive beam forming algorithm, which has been widely used in the GPS receivers [13]. The optimal weights are obtained by iterative operations according to the minimum mean square error (MMSE).…”

Section: System Modelmentioning

confidence: 99%

Jamming Method Based on Optimal Power Difference for LMS-GPS Receiver

Liu¹,

Wang²,

Yue³

et al. 2019

Self Cite

Jamming and anti-jamming techniques for global position systems (GPS) play important roles in electronic countermeasure. Least mean square (LMS)-based anti-jamming algorithm is widely used in GPS receivers, since it can avoid matrix inversion and has low complexity. For convenience, we call them LMS-GPS receivers. To improve the anti-jamming performance of the LMS-GPS receivers, it is very meaningful to study the jamming technique. Considering that existing jamming signals are easily suppressed by LMS-GPS receivers, a new jamming method named as optimal power difference jamming is proposed in this paper to improve the jamming effect further. Specifically, the analytical relationship between jamming-to-signal ratio (JSR) and the power difference of two interference signals is firstly given. Then, the conclusion that there is always an optimal power difference where the JSR can take the extreme value is drawn. Finally, the optimal power difference is derived as about 22 dB for single-tone interference and 29 dB for band-limited Gaussian noise interference. Simulation results show that the proposed method with optimal power difference is able to improve the JSR remarkably.

“…Therefore, the space-time adaptive antijamming method is developed to overcome the aforementioned problem, and several delay taps are placed behind each antenna element, namely, a temporal filtering is added on the basis of the spatial filtering. Thus, the space-time adaptive antijamming method can suppress more interference signals owing to the addition of temporal DOF [5][6][7][8][9][10]. A distortionless spacetime adaptive antijamming method is presented [5], which can not only obtain a higher DOF but also enhance the gain of GNSS signals.…”

Section: Introductionmentioning

confidence: 99%

Adaptive Antijamming Based on Space-Time 2-D Sparse Array for GNSS Receivers

Du¹,

Liu²,

Tang³

et al. 2020

Self Cite

Space-time adaptive antijamming problem has received significant attention recently for global navigation satellite system (GNSS). It can jointly utilize spatial filters and temporal filters to suppress interference signals. However, most of the works on space-time antijamming problem presented in the literature require a space-time two-dimension (2-D) array with multiple antennas and delay taps. In this paper, an effective adaptive antijamming method based on a space-time 2-D sparse array is proposed. The maximum array gain is utilized to construct a space-time 2-D sparse array. The spacetime antijamming weight vector is given by minimizing the 2-D sparse array output power. Compared with the previous works, the presented method can have better antijamming performance than a spacetime 2-D uniform array. Simulation results verify the effectiveness and feasibility of the proposed method.