Topic
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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01 Jan 2005
TL;DR: It is shown that the antenna main lobe remains stable in the presence of position errors and sensor failures, and thus can be steered in an adaptive manner as a UAV files past.
Abstract: We present an adaptive distributed beamforming approach for sensor networks, wherein sensor nodes coordinate their transmissions to form a distributed antenna array that directs a beam toward an airborne relay (an unmanned aerial vehicle). Distributed beamforming using sensors is challenging since the number of nodes and their exact positions are unknown. A simulation model was implemented to study adaptive beamforming, and results are compared to theoretical results for random arrays. We show that the antenna main lobe remains stable in the presence of position errors and sensor failures, and thus can be steered in an adaptive manner as a UAV files past
27 citations
TL;DR: Theoretical analysis and simulation results indicate that these beamformers improve in performance with every iterative step and converge to a stabilized solution, and the iterative convergence properties are proved.
27 citations
14 May 2006
TL;DR: It is demonstrated how the data dimensionality reduction obtained from Krylov pre-processing decreases the sensitivity of reduced-rank adaptive beamforming techniques to incorrect model-order selection and lessens the computational complexity of systems involving large arrays with many elements.
Abstract: In this work, we present a class of low-complexity reduced-dimension adaptive beamformers constructed from expanding Krylov subspaces. We demonstrate how the data dimensionality reduction obtained from Krylov pre-processing decreases the sensitivity of reduced-rank adaptive beamforming techniques to incorrect model-order selection and lessens the computational complexity of systems involving large arrays with many elements. An important advantage of the proposed dimensionality reduction scheme is that it relieves reduced-rank methods from the stringent requirement on the precise model order determination.
27 citations
TL;DR: Theoretical analysis and real-time experiments show the superiority of the robust adaptive beamforming integrating stereophonic acoustic echo cancellation concept over comparable time-domain approaches in terms of computational complexity and adaptation behaviour.
Abstract: A concept of robust adaptive beamforming integrating stereophonic acoustic echo cancellation is presented which reconciles the need for low-computational complexity and efficient adaptive filtering with versatility and robustness in real-world scenarios. The synergetic combination of a robust generalized sidelobe canceller and a stereo acoustic echo canceller is designed in the frequency domain based on a general framework for multichannel adaptive filtering in the frequency domain. Theoretical analysis and real-time experiments show the superiority of this concept over comparable time-domain approaches in terms of computational complexity and adaptation behaviour. The real-time implementation confirms that the concept is robust and meets well the practical requirements of real-world scenarios, which makes it a promising candidate for commercial products.
27 citations
TL;DR: Computer simulation results are presented, which show that the algorithms proposed here yield significantly better performance as compared to the previous algorithms of Gershman et al. and Hung and Turner in a variety of situations required to handle wide-band, moving, and coherent jammers.
Abstract: The problem of providing robustness to the conventional narrow-band uniform linear array configuration so as to handle wide-band and moving jammers is addressed. This robustness is achieved via the use of derivative constraints in jammer directions. However, since the jammer directions are not known a priori, these constraints are incorporated with a maximum likelihood characterization of the so-called jammer subspace. This formulation does not need to assume the availability of signal-free observations, as stipulated in earlier work. Computer simulation results are presented, which show that the algorithms proposed here yield significantly better performance as compared to the previous algorithms of Gershman et al. (see ibid., vol.44, p.361-6, 1996, and IEEE Trans. Signal Processing, vol.45, p.1878-85, 1997) and Hung and Turner (1983) in a variety of situations required to handle wide-band, moving, and coherent jammers.
26 citations