208 research outputs found
Sidelobe Suppression for Capon Beamforming with Mainlobe to Sidelobe Power Ratio Maximization
High sidelobe level is a major disadvantage of the Capon beamforming. To
suppress the sidelobe, this paper introduces a mainlobe to sidelobe power ratio
constraint to the Capon beamforming. it minimizes the sidelobe power while
keeping the mainlobe power constant. Simulations show that the obtained
beamformer outperforms the Capon beamformer.Comment: 8 pages, 2 figure
Quadratically Constrained Beamforming Robust Against Direction-of-Arrival Mismatch
It is well known that the performance of the minimum variance distortionless response (MVDR) beamformer is very sensitive to steering vector mismatch. Such mismatches can occur as a result of direction-of-arrival (DOA) errors, local scattering, near-far spatial signature mismatch, waveform distortion, source spreading, imperfectly calibrated arrays and distorted antenna shape. In this paper, an adaptive beamformer that is robust against the DOA mismatch is proposed. This method imposes two quadratic constraints such that the magnitude responses of two steering vectors exceed unity. Then, a diagonal loading method is used to force the magnitude responses at the arrival angles between these two steering vectors to exceed unity. Therefore, this method can always force the gains at a desired range of angles to exceed a constant level while suppressing the interferences and noise. A closed-form solution to the proposed minimization problem is introduced, and the diagonal loading factor can be computed systematically by a proposed algorithm. Numerical examples show that this method has excellent signal-to-interference-plus-noise ratio performance and a complexity comparable to the standard MVDR beamformer
A new method for robust beamforming using iterative second-order cone programming
This paper addresses the problem of beamforming for antenna arrays in the presence of mismatches between the true and nominal steering vectors. A new method for robust beamforming is proposed by minimizing the array output power while controlling the array mainlobe response. Due to the presence of the non-convex response constraints, a new approach based on iteratively linearizing the non-convex constraints is proposed to reformulate the non-convex problem to a series of second-order cone programming (SOCP) subproblems, each of which can be optimally solved by well-established convex optimization techniques. Simulation results show that the proposed method offers better performance than conventional methods tested. © 2012 IEEE.published_or_final_versionThe 2012 IEEE International Symposium on Circuits and Systems (ISCAS), Seoul, Korea, 20-23 May 2012. In IEEE International Symposium on Circuits and Systems Proceedings, 2012, p. 2569-257
A Robust Beamformer Based on Weighted Sparse Constraint
Applying a sparse constraint on the beam pattern has been suggested to
suppress the sidelobe level of a minimum variance distortionless response
(MVDR) beamformer. In this letter, we introduce a weighted sparse constraint in
the beamformer design to provide a lower sidelobe level and deeper nulls for
interference avoidance, as compared with a conventional MVDR beamformer. The
proposed beamformer also shows improved robustness against the mismatch between
the steering angle and the direction of arrival (DOA) of the desired signal,
caused by imperfect estimation of DOA.Comment: 4 pages, 2 figure
A robust adaptive beamforming method based on the matrix reconstruction against a large DOA mismatch
- …