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This work presents a highly optimized computational framework for the Discrete Dipole Approximation, a numerical method for calculating the optical properties associated with a target of arbitrary geometry that is widely used in…

Instrumentation and Methods for Astrophysics · Physics 2009-08-07 James Mc Donald , Aaron Golden , S. Gerard Jennings

This paper jointly designs linear precoding (LP) and codebook-based beamforming implemented in a satellite with massive multiple-input multiple-output (mMIMO) antenna technology. The codebook of beamforming weights is built using the…

Large-scale contrastive vision-language pre-trained models provide the zero-shot model achieving competitive performance across a range of image classification tasks without requiring training on downstream data. Recent works have confirmed…

Machine Learning · Computer Science 2024-04-02 Giung Nam , Byeongho Heo , Juho Lee

Millimeter wave communications are essential for modern wireless networks. It supports high data rates but suffers from severe path loss, which requires precise beam alignment to maintain reliable links. This beam management is particularly…

Signal Processing · Electrical Eng. & Systems 2025-11-05 Ailton Oliveira , Amir Khatibi , Daniel Suzuki , Ilan Correa , José Rezende , Aldebaro Klautau

In future 6G communication systems, large-scale antenna arrays promise enhanced signal strength and spatial resolution, but they also increase the complexity of beam training. Moreover, as antenna counts grow and carrier wavelengths shrink,…

Information Theory · Computer Science 2025-09-22 Ran Li , Ziyi Xu , Ying-Jun Angela Zhang

Reconfigurable intelligent surfaces (RIS) can reshape the characteristics of wireless channels by intelligently regulating the phase shifts of reflecting elements. Recently, various codebook schemes have been utilized to optimize the…

Information Theory · Computer Science 2025-04-01 Zhiheng Yu , Jiancheng An , Lu Gan , Hongbin Li , Symeon Chatzinotas

Extremely large-scale massive MIMO (XL-MIMO) is a promising technique for future 6G communications.However, existing far-field or near-field channel model mismatches the hybrid-field channel feature in the practical XL-MIMO…

Information Theory · Computer Science 2021-11-23 Xiuhong Wei , Linglong Dai

Classical Density Functional Theory (DFT) is a statistical-mechanical framework to analyze fluids, which accounts for nanoscale fluid inhomogeneities and non-local intermolecular interactions. DFT can be applied to a wide range of…

Computational Engineering, Finance, and Science · Computer Science 2017-02-07 Andreas Nold , Benjamin D. Goddard , Peter Yatsyshin , Nikos Savva , Serafim Kalliadasis

Extremely large-scale multiple-input multiple-output (XL-MIMO) is regarded as one of the key techniques to enhance the performance of future wireless communications. Different from regular MIMO, the XL-MIMO shifts part of the communication…

Information Theory · Computer Science 2024-10-16 Kangjian Chen , Chenhao Qi , Jingjia Huang , Octavia A. Dobre , Geoffrey Ye Li

Near-field (NF) line-of-sight (LoS) MIMO systems enable efficient channel state information (CSI) acquisition and precoding by exploiting known antenna geometries at both the base station (BS) and user equipment (UE). This paper introduces…

Signal Processing · Electrical Eng. & Systems 2025-05-08 Shima Eslami , Bikshapathi Gouda , Antti Tölli

This paper proposes a multi-user Spatial Division Multiplexing (SDM) near-field access scheme, inspired by the orthogonal characteristics of multi-mode vortex waves. A Reconfigurable Meta-surface (RM) is ingeniously employed as the gateway…

Signal Processing · Electrical Eng. & Systems 2025-02-26 Yufei Zhao , Qihao Lv , Yuanbin Chen , Afkar Mohamed Ismail , Yong Liang Guan , Chau Yuen

Enhancing high-speed wireless communication in the future relies significantly on harnessing high frequency bands effectively. These bands predominantly operate in line-of-sight (LoS) paths, necessitating well-configured antenna arrays and…

Information Theory · Computer Science 2024-04-09 Jiyoung Yun , Hojun Rho , Wan Choi

In this letter, we study efficient near-field beam training design for the extremely large-scale array (XL-array) communication systems. Compared with the conventional far-field beam training method that searches for the best beam direction…

Information Theory · Computer Science 2022-09-30 Yunpu Zhang , Xun Wu , Changsheng You

Near-field extremely large multiple input multiple output (XL-MIMO) breaks the assumptions that make classical super-resolution effective: the receiver acquires only a limited set of compressed pilot observations, while each propagation…

Signal Processing · Electrical Eng. & Systems 2026-04-14 Sajad Daei , Gabor Fodor , Mikael Skoglund

Spatial division multiple access (SDMA), a powerful method routinely applied in multi-user multiple-input multiple-output (MIMO) communications, relies on the angular orthogonality of beams in the far field, to distinguish multiple users at…

Signal Processing · Electrical Eng. & Systems 2024-08-26 Sotiris Droulias , Giorgos Stratidakis , Angeliki Alexiou

Static correlation is a difficult problem for density-functional theory (DFT) as it arises in cases of degenerate or quasi-degenerate states where a multideterminantal wave function provides the simplest reasonable first approximation to…

Chemical Physics · Physics 2024-01-01 Abraham Ponra , Carolyne Bakasa , Anne Justine Etindele , Mark E. Casida

Medical image segmentation has achieved remarkable advancements using deep neural networks (DNNs). However, DNNs often need big amounts of data and annotations for training, both of which can be difficult and costly to obtain. In this work,…

Computer Vision and Pattern Recognition · Computer Science 2021-10-19 Hengji Cui , Dong Wei , Kai Ma , Shi Gu , Yefeng Zheng

Future wireless systems are expected to employ extremely large-scale multiple-input multiple-output (XL-MIMO) arrays at high carrier frequencies, where near-field propagation makes the channel depend jointly on angle and distance. The…

Signal Processing · Electrical Eng. & Systems 2026-05-27 Maral Safari , Italo Atzeni

Background: Windowed Fourier decompositions (WFD) are widely used in measuring stationary and non-stationary spectral phenomena and in describing pairwise relationships among multiple signals. Although a variety of WFDs see frequent…

Quantitative Methods · Quantitative Biology 2019-01-30 Christopher K. Kovach , Phillip E. Gander

Affine Frequency Division Multiplexing (AFDM), a new chirp-based multicarrier waveform for high mobility communications, is introduced here. AFDM is based on discrete affine Fourier transform (DAFT), a generalization of discrete Fourier…

Information Theory · Computer Science 2022-05-04 Ali Bemani , Nassar Ksairi , Marios Kountouris