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Optical aberrations prevent telescopes from reaching their theoretical diffraction limit. Once estimated, these aberrations can be compensated for using deformable mirrors in a closed loop. Focal plane wavefront sensing enables the…

Ultrasonic backscatter measurements are widely used for microstructural characterisation. However, in materials containing strong anisotropy and spatial heterogeneity, the interpretation of backscatter signals becomes challenging because…

Applied Physics · Physics 2026-05-22 Wei Yi Yeoh , Bo Lan , Michael J. S. Lowe

Cellular uplink analysis has typically been undertaken by either a simple approach that lumps all interference into a single deterministic or random parameter in a Wyner-type model, or via complex system level simulations that often do not…

Information Theory · Computer Science 2016-11-17 Thomas D. Novlan , Harpreet S. Dhillon , Jeffrey G. Andrews

In this work, we study the effect of beam deviation angle at the reception side and calculate the theoretical demultiplexed collected energy for up to 15 modes, investigating the influence of the ratio between incoming beam size and…

Satellite-based communications are expected to be a substantial future market in 6G networks. As satellite constellations grow denser and transmission resources remain limited, frequency reuse plays an increasingly important role in…

Signal Processing · Electrical Eng. & Systems 2025-10-30 Alea Schröder , Steffen Gracla , Carsten Bockelmann , Dirk Wübben , Armin Dekorsy

Massive MIMO OFDM waveforms help support a large number of users in the same time-frequency resource and also provide significant array gain for uplink reception in cellular systems. However, channel estimation in such large antenna systems…

Information Theory · Computer Science 2024-06-04 P Aswathylakshmi , Radha Krishna Ganti

Location-aware communication systems are expected to play a pivotal part in the next generation of mobile communication networks. Therefore, there is a need to understand the localization limits in these networks, particularly, using…

Information Theory · Computer Science 2018-11-29 Zohair Abu-Shaban , Xiangyun Zhou , Thushara Abhayapala , Gonzalo Seco-Granados , Henk Wymeersch

Achieving integrated sensing and communication (ISAC) via uplink transmission is challenging due to the unknown waveform and the coupling of communication and sensing echoes. In this paper, a joint uplink communication and imaging system is…

Signal Processing · Electrical Eng. & Systems 2023-01-11 Shengyu Zhu , Zehua Yu , Qinghua Guo , Jinshan Ding , Qiang Cheng , Tie Jun Cui

Reuse-1 systems operating in the sub-1 GHz UHF band are limited by substantial co-channel interference (CCI). In such orthogonal frequency division multiple access (OFDMA) cellular systems, the inter-sector or inter-tower interference (ITI)…

Information Theory · Computer Science 2022-11-16 Abhay Mohan M , Giridhar K

Recent constellations of satellites, including the Skysat constellation, are able to acquire bursts of images. This new acquisition mode allows for modern image restoration techniques, including multi-frame super-resolution. As the…

Computer Vision and Pattern Recognition · Computer Science 2021-02-05 Jérémy Anger , Thibaud Ehret , Gabriele Facciolo

Reciprocity-based beamforming-most commonly employed in time-division duplexing-uses noisy, estimated (i.e., measured) channel state information (CSI) acquired on the uplink. While computationally efficient, reciprocity-based beamforming…

Signal Processing · Electrical Eng. & Systems 2025-03-25 Benjamin J. B. Deutschmann , Erik Leitinger , Klaus Witrisal

Nowadays, panoramic images can be easily obtained by panoramic cameras. However, when the panoramic camera orientation is tilted, a non-upright panoramic image will be captured. Existing upright adjustment models focus on how to estimate…

Computer Vision and Pattern Recognition · Computer Science 2023-04-13 Heyu Chen , Jianfeng Li , Shigang Li

The emerging space-air-ground integrated network has attracted intensive research and necessitates reliable and efficient aeronautical communications. This paper investigates terahertz Ultra-Massive (UM)-MIMO-based aeronautical…

Information Theory · Computer Science 2021-03-04 Anwen Liao , Zhen Gao , Dongming Wang , Hua Wang , Hao Yin , Derrick Wing Kwan Ng , Mohamed-Slim Alouini

Reliable transmission of quantum optical states through real-world environments is key for quantum communication and imaging. Yet, aberrations and scattering in the propagation path can scramble the transmitted signal and hinder its use. A…

Quantum Physics · Physics 2025-09-05 Shaurya Aarav , Hugo Defienne

Increasing interest in astronomical applications of non-linear curvature wavefront sensors for turbulence detection and correction makes it important to understand how best to handle the data they produce, particularly at low light levels.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 P. L. Aisher , J. Crass , C. Mackay

The document covers the fundamental algorithm of backward propagation from the point of view of reconstructing the wavefield captured by a "screen" in an imaging system. Owing to a property of the Helmholtz equation, wavefields have an…

Image and Video Processing · Electrical Eng. & Systems 2020-04-20 Anurag Pallaprolu

Perceptive mobile networks (PMNs), integrating ubiquitous sensing capabilities into mobile networks, represent an important application of integrated sensing and communication (ISAC) in 6G. In this paper, we propose a practical framework…

Signal Processing · Electrical Eng. & Systems 2025-03-14 Liangbin Zhao , Zhitong Ni , Yimeng Feng , Jianguo Li , Xiangyuan Bu , J. Andrew Zhang

A low-divergence beam is an essential prerequisite for a high-efficiency longdistance optical link, particularly for satellite-based quantum communication. A point-ahead angle, caused by satellite motion, is always several times larger than…

This paper presents a novel optimization framework for beamforming design in integrated sensing and communication systems where a base station seeks to minimize the Bayesian Cram\'er-Rao bound of a sensing problem while satisfying quality…

Information Theory · Computer Science 2024-04-23 Kareem M. Attiah , Wei Yu

In pulse-echo ultrasound, aberration often degrades image quality when beamforming does not account for wavefront distortions. To address this issue, local sound speed estimators have been developed in the past decade for distributed…

Medical Physics · Physics 2026-05-08 Louise Zhuang , Samuel Beuret , Ben Frey , Saachi Munot , Walter Simson , Dongwoon Hyun , Jeremy J. Dahl