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Acoustic source localization and sound recognition are common acoustic scene analysis tasks that are usually considered separately. In this paper, a new source localization technique is proposed that works jointly with an acoustic event detection system. Given the identities and the end-points of simultaneous sounds, the proposed technique uses the statistical models of those sounds to compute a likelihood...
Advances in hardware and communication technology make distributed sound acquisition increasingly attractive. We describe a distributed beamforming method based on the diffusion adaptation paradigm. In contrast to existing distributed beamforming methods, the method does not impose conditions on the topology or the structure of the network nor does it require knowledge of the noise co-variance matrix...
The minimum variance distortionless response (MVDR) beam-former has been widely studied for extraction of desired speech signals in noisy acoustic environments. The performance of this beam-former, however, depends on many factors such as the array geometry, the source incidence angle, the noise field characteristics, the reverberation conditions, etc. In this paper, we study the performance of the...
This paper proposes a new generalized sidelobe canceller with a compact array of microphones suitable for mobile terminals. The output of the fixed beamformer (FBF) is further processed by a newly introduced decorrelation unit which has an auxiliary input signal to improve poor interference suppression of FBF in low frequencies. The output of the decorrelation unit is used as the reference signal...
A randomly positioned microphone array is considered in this work. In many applications, the locations of the array elements are known up to a certain degree of random mismatch. We derive a novel statistical model for performance analysis of the multi-channel Wiener filter (MWF) beamformer under random mismatch in sensors location. We consider the scenario of one desired source and one interfering...
We consider the problem of electroencephalography (EEG) and magnetoencephalography (MEG) source localization using beamforming techniques. Specifically, we propose a reduced-rank extension of the recently derived multi-source activity index (MAI), which itself is an extension of the classical neural activity index to the multi-source case. We show that, for uncorrelated dipole sources and any nonzero...
This paper presents an investigation of far field speech recognition using beamforming and channel concatenation in the context of Deep Neural Network (DNN) based feature extraction. While speech enhancement with beamforming is attractive, the algorithms are typically signal-based with no information about the special properties of speech. A simple alternative to beamforming is concatenating multiple...
This paper addresses the problem of RF-based wide-area human motion monitoring in indoor multipath environments. A major challenge for conventional pulse-Doppler radar in mul-tipath scenarios is the difficulty in discriminating direct-path targets from ghost returns due to multipath scattering. In this paper, the ability of a multiple-input multiple-output (MIMO) RF probe to discern both direction-of-departure...
We consider physical-layer security of a wireless LAN where multiple receivers collude to eavesdrop the information from the basestation to the intended receiver. To enhance the physical-layer security, we design the interference signals to combat the eavesdropping. Our design problems are resolved using semidefinite relaxation problems, which can be numerically solved efficiently by the existing...
In this work, we propose an adaptive set-membership (SM) reduced-rank filtering algorithm using the constrained constant modulus (CCM) criterion for beamforming. We develop a stochastic gradient (SG) type algorithm based on the concept of SM technique for adaptive implementation. The filter weights are updated only if the bounded constraint cannot be satisfied. In addition, we also propose a scheme...
Beamformer-assisted acoustic echo cancelers have raised a lot of interest lately. The same performance can be obtained with a reduced length acoustic echo canceler (AEC) as the beamformer (BF) performs spatial cancellation. Structures that jointly optimize the BF and the AEC coefficients are preferred in order to exploit synergies. Analytical models have been already derived for the behavior of the...
Depth imaging is commonly based on light. For example, LIDAR and Kinect use infrared light, while stereo cameras use visible light. These systems require hardware operating at high sampling frequencies, precise calibration, and they dissipate significant power. In this paper, we investigate the potential of ultrasound for image and depth acquisition, with applications to human-computer interaction...
Contemporary sonography is performed by digitally beamforming signals sampled by several transducer elements placed upon an array. High-resolution digital beamforming introduces the demand for a sampling rate significantly higher than the signal's Nyquist rate, which greatly increases the volume of data that must be processed. In 3D ultrasound imaging, 2D transducer arrays rather than 1D arrays are...
The Square Kilometre Array (SKA) is a future radio telescope, currently being designed by the worldwide radio-astronomy community. During the first of two construction phases, more than 250,000 antennas will be deployed, clustered in aperture-array stations. The antennas will generate 2.5 Pb/s of data, which needs to be processed in real time. For the processing stages from A/D conversion to central...
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