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Adaptive beamformer

About: Adaptive beamformer is a research topic. Over the lifetime, 4934 publications have been published within this topic receiving 93100 citations.


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Patent
Debajyoti Pal1
09 Nov 1994
TL;DR: In this paper, a singular value decomposition of the auto-covariance matrix is used to form three matrices, the first matrix determines the number of signal paths, the second matrix determines several polynomials, and the third matrix determines points on the unit circle that are associated with each signal path.
Abstract: Signals from multiple signal paths are received using a multi-element antenna (20) and a beam-forming network (36). Signals from each of the antenna elements are sampled (34) to form a sample vector. Several sample vectors are used to form an auto-covariance matrix. A singular value decomposition of the auto-covariance matrix is used to form three matrices. The first matrix is used to determine the number of signal paths and the second matrix is used to form several polynomials. The polynomial roots that are on or near the unit circle are used to determine points on the unit circle that are associated with each signal path. Each point on the unit circle is used to calculate weights for a beam-forming network (36) that forms a receive beam for each signal path.

17 citations

Journal ArticleDOI
TL;DR: In this article, a novel scheme for a subband adaptive beamforming array (SABA) implementation is presented, where the higher subband output signal is optimised and then multiplied with a factor to generate an output similar to the optimised lower subband.
Abstract: A novel scheme for a subband adaptive beamforming array (SABA) implementation is presented. The higher subband output signal is optimised and then multiplied with a factor to generate an output similar to the optimised lower subband. Both outputs are then combined to produce the desired signal. This arrangement reduces circuit complexity as well as the cost of the SABA, while maintaining the same beamforming performance.

17 citations

Journal ArticleDOI
TL;DR: In this article, a perturbation sequence for an adaptive beamformer is described, which permits simultaneous adaption and reception by use of weight perturbations that do not obstruct the look direction constraint.
Abstract: The generation of a perturbation sequence for an adaptive beamformer is described. This perturbation sequence permits simultaneous adaption and reception by use of weight perturbations that do not obstruct the look direction constraint. It is shown that this sequence is generally shorter in length than previously described sequences and offers scope for computational savings through reduction of the number of projection operations required. Convergence in the mean of the resulting adaptive algorithm is demonstrated. Experiments conducted using a four-element linear array operating in the MW RF range have confirmed that the predicted results are achievable under the nonideal conditions of quantized array weights and finite word length arithmetic. >

17 citations

Proceedings ArticleDOI
14 Oct 1997
TL;DR: In this paper, the authors proposed a constrained adaptive beam pattern synthesis (CAPS) algorithm, which combines the benefits of subspace and penalty function approaches to overcome the problem of high sidelobes and weight jitter while maintaining an acceptable SNIR.
Abstract: The primary objective of adaptive beamforming is to suppress jamming signals while maintaining the response of the array in the desired signal direction. It is also desirable to obtain low sidelobes in the adaptive beam pattern and to minimise sidelobe jitter in order to aid the performance against clutter and pulsed deception jammers. Sample matrix inversion (SMI) is one of the simplest adaptive beamforming algorithms, involving minimisation of the average output power for a set of input data vectors (snapshots), subject to constraints on the beam pattern. However, the basic SMI algorithm tends to produce beam patterns with high sidelobes away from the jammer directions and considerable weight and sidelobe jitter. Penalty function methods as given in Hughes and McWhirter (see SPIE Proc.2563, p.170-81) and methods based on subspace projection e.g. Richardson (see Proc. of EUSIPCO-94, vol.3, p.1301-4, 1994), are two types of method which can be used to overcome the problem of high sidelobes and weight jitter while maintaining an acceptable signal to noise plus interference ratio (SNIR). This paper presents a new algorithm, which has been termed `constrained adaptive beam pattern synthesis' (CAPS). It is a projection based algorithm which incorporates the pattern fitting element of penalty function methods in order to obtain the best possible sidelobe levels. It therefore combines the benefits of subspace and penalty function approaches. Following an explanation of the algorithm, an investigation of its performance in the presence of mainlobe and sidelobe jamming is presented.

17 citations

Patent
30 Sep 2011
TL;DR: In this paper, a beamforming technique for a microphone array is described to attenuate a source of undesired noise that is deemed the most limiting to audio quality in an acoustic environment.
Abstract: A beamforming technique for a microphone array is described to attenuate a source of undesired noise that is deemed the most limiting to audio quality in an acoustic environment. Possible sources of undesired noise include echo, background noise (stationary) and other interference signals (non-stationary). The beamforming technique is updated based on long-term evaluations. Once an evaluation occurs and a decision is made, the beamformer adapts with a maximum responsiveness and without intentional delay, and therefore not affecting the beamformer's tracking ability. When fixed beamforming is utilized, one of several fixed beamformers having different attenuation targets are selected to implement noise attenuation. When adaptive beamforming is utilized, the beamformer adapts whenever the selected target is deemed dominant.

17 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202371
2022168
2021133
2020154
2019198
2018154