Results 1 to 10 of about 123,247 (141)

3D Super-Resolution Ultrasound with Adaptive Weight-Based Beamforming [PDF]

, 2022
Super-resolution ultrasound (SRUS) imaging through localising and tracking sparse microbubbles has been shown to reveal microvascular structure and flow beyond the wave diffraction limit. Most SRUS studies use standard delay and sum (DAS) beamforming, where large main lobe and significant side lobes make separation and localisation of densely ...
arxiv   +1 more source

Adaptive Dereverberation, Noise and Interferer Reduction Using Sparse Weighted Linearly Constrained Minimum Power Beamforming [PDF]

, 2023
Interfering sources, background noise and reverberation degrade speech quality and intelligibility in hearing aid applications. In this paper, we present an adaptive algorithm aiming at dereverberation, noise and interferer reduction and preservation of binaural cues based on the wBLCMP beamformer.
arxiv   +1 more source

IRS-Aided WPCNs: A New Optimization Framework for Dynamic IRS Beamforming [PDF]

arXiv, 2021
In this paper, we propose a new dynamic IRS beamforming framework to boost the sum throughput of an intelligent reflecting surface (IRS) aided wireless powered communication network (WPCN). Specifically, the IRS phase-shift vectors across time and resource allocation are jointly optimized to enhance the efficiencies of both downlink wireless power ...
arxiv  

Contextual Beamforming: Exploiting Location and AI for Enhanced Wireless Telecommunication Performance [PDF]

arXiv, 2023
The pervasive nature of wireless telecommunication has made it the foundation for mainstream technologies like automation, smart vehicles, virtual reality, and unmanned aerial vehicles. As these technologies experience widespread adoption in our daily lives, ensuring the reliable performance of cellular networks in mobile scenarios has become a ...
arxiv  

Quadratic Matrix Inequality Approach to Robust Adaptive Beamforming for General-Rank Signal Model [PDF]

IEEE Trans. Signal Processing, vol. 68, pp. 2244-2255, 2020, 2019
The worst-case robust adaptive beamforming problem for general-rank signal model is considered. This is a nonconvex problem, and an approximate version of it (obtained by introducing a matrix decomposition on the presumed covariance matrix of the desired signal) has been well studied in the literature.
arxiv   +1 more source

Joint Waveform and Beamforming Optimization for MIMO Wireless Power Transfer [PDF]

, 2020
In this paper, we study a multi-sine multiple-input multiple-output (MIMO) wireless power transfer (WPT) system with the objective to increase the output DC power. We jointly optimize the multi-sine waveform and beamforming accounting for the rectenna nonlinearity, and consider two combining schemes for the rectennas at the receiver, namely DC and RF ...
arxiv   +1 more source

Deep Long Short-Term Memory Adaptive Beamforming Networks For Multichannel Robust Speech Recognition [PDF]

2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), New Orleans, LA, 2017, pp. 271-275, 2017
Far-field speech recognition in noisy and reverberant conditions remains a challenging problem despite recent deep learning breakthroughs. This problem is commonly addressed by acquiring a speech signal from multiple microphones and performing beamforming over them. In this paper, we propose to use a recurrent neural network with long short-term memory
arxiv   +1 more source

Adaptive Time-Channel Beamforming for Time-of-Flight Correction [PDF]

arXiv, 2021
Adaptive beamforming can lead to substantial improvement in resolution and contrast of ultrasound images over standard delay and sum beamforming. Here we introduce the adaptive time-channel (ATC) beamformer, a data-driven approach that combines spatial and temporal information simultaneously, thus generalizing minimum variance beamformers. Moreover, we
arxiv  

Low-Cost Maximum Entropy Covariance Matrix Reconstruction Algorithm for Robust Adaptive Beamforming [PDF]

arXiv, 2020
In this letter, we present a novel low-complexity adaptive beamforming technique using a stochastic gradient algorithm to avoid matrix inversions. The proposed method exploits algorithms based on the maximum entropy power spectrum (MEPS) to estimate the noise-plus-interference covariance matrix (MEPS-NPIC) so that the beamforming weights are updated ...
arxiv  

Medical Photoacoustic Beamforming Using Minimum Variance-Based Delay Multiply and Sum [PDF]

Proceedings Volume 10335, Digital Optical Technologies 2017; 1033522 (2017), 2018
Delay-and-Sum (DAS) beamformer is the most common beamforming algorithm in Photoacoustic imaging (PAI) due to its simple implementation and real time imaging. However, it provides poor resolution and high levels of sidelobe. A new algorithm named Delay-Multiply-and-Sum (DMAS) was introduced. Using DMAS leads to lower levels of sidelobe compared to DAS,
arxiv   +1 more source