Journal ArticleDOI
Quadratically constrained adaptive beamforming for coherent signals and interference
Feng Qian,B.D. Van Veen +1 more
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TLDR
It is shown that if the quadratic constraint is properly chosen, then the original linearly constrained beamformer's signal cancellation is reduced to an arbitrarily small level while the interference cancellation is unchanged.Abstract:
Severe signal cancellation often occurs in conventional adaptive beamforming if coherent interferers are present. The paper proposes adding quadratic constraints to a linearly constrained minimum variance (LCMV) adaptive beamformer to prevent signal cancellation in coherent interference environments. The additional constraint limits the beamformer output mean squared error to be less than a specified level. It is shown that if the quadratic constraint is properly chosen, then the original linearly constrained beamformer's signal cancellation is reduced to an arbitrarily small level while the interference cancellation is unchanged. In practice, the quadratic constraint is constructed based on estimates of the interference parameters. Sensitivity analyses show the performance of the resulting beamformer is robust with respect to this approximate constraint. The effectiveness of the quadratically constrained adaptive beamformer is further illustrated through simulations. >read more
Citations
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Journal ArticleDOI
Application of antenna arrays to mobile communications. II. Beam-forming and direction-of-arrival considerations
TL;DR: This paper provides a comprehensive and detailed treatment of different beam-forming schemes, adaptive algorithms to adjust the required weighting on antennas, direction-of-arrival estimation methods-including their performance comparison-and effects of errors on the performance of an array system, as well as schemes to alleviate them.
Journal ArticleDOI
Quadratically Constrained Beamforming Robust Against Direction-of-Arrival Mismatch
Chun-Yang Chen,P.P. Vaidyanathan +1 more
TL;DR: An adaptive beamformer that is robust against the DOA mismatch is proposed, and a closed-form solution to the proposed minimization problem is introduced, and the diagonal loading factor can be computed systematically by a proposed algorithm.
Book ChapterDOI
Adaptive Beamforming for Audio Signal Acquisition
TL;DR: From this, a robust generalized sidelobe canceller (GSC) results as an attractive solution for practical audio acquisition systems and the general theoretical framework leads to new insights for the GSC behavior in complex practical situations.
Journal ArticleDOI
Robust near-field adaptive beamforming with distance discrimination
TL;DR: It is shown with a nine-element uniform linear array that the proposed near-field adaptive beamformer is robust against distance errors as large as /spl plusmn/32% of the presumed radial distance and angle errors up to /splplusmn/20/spl deg/.
DissertationDOI
Signal processing algorithms for mimo radar
P.P. Vaidyanathan,Chun-Yang Chen +1 more
TL;DR: The main contribution of this thesis is to study the signal processing issues in MIMO radar and propose novel algorithms for improving the MIMo radar system, including an adaptive beamformer that is robust against the DOA mismatch.
References
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Journal ArticleDOI
An algorithm for linearly constrained adaptive array processing
TL;DR: A constrained least mean-squares algorithm has been derived which is capable of adjusting an array of sensors in real time to respond to a signal coming from a desired direction while discriminating against noises coming from other directions.
Journal ArticleDOI
An alternative approach to linearly constrained adaptive beamforming
L.J. Griffiths,C. Jim +1 more
TL;DR: A beamforming structure is presented which can be used to implement a wide variety of linearly constrained adaptive array processors and is shown to incorporate algorithms which have been suggested previously for use in adaptive beamforming as well as to include new approaches.
Journal ArticleDOI
Robust adaptive beamforming
TL;DR: It is shown that a simple scaling of the projection of tentative weights, in the subspace orthogonal to the linear constraints, can be used to satisfy the quadratic inequality constraint.
Journal ArticleDOI
Coherent signal-subspace processing for the detection and estimation of angles of arrival of multiple wide-band sources
H. Wang,Mostafa Kaveh +1 more
TL;DR: In this paper, a method of constructing a single signal subspace for high-resolution estimation of the angles of arrival of multiple wide-band plane waves is presented, which relies on an approximately coherent combination of the spatial signal spaces of the temporally narrow-band decomposition of the received signal vector from an array of sensors.
Journal ArticleDOI
Adaptive beamforming for coherent signals and interference
Tie-Jun Shan,Thomas Kailath +1 more
TL;DR: A new adaptive array beam-former able to work well even when the desired signal and the interference are coherent, and the results of simulations support the theoretical predictions.