English
Related papers

Related papers: Cophasing multiple aperture telescopes with Linear…

200 papers

In this paper, we consider the problem of iterative detection and decoding (IDD) for multi-antenna systems using low-density parity-check (LDPC) codes. The proposed IDD system consists of a soft-input soft-output parallel interference (PIC)…

Information Theory · Computer Science 2013-04-24 Jingjing Liu , Peng Li , Rodrigo C. de Lamare

We propose a learning-based method for adaptively generating low probability of detection (LPD) radar waveforms that blend into their operating environment. Our waveforms are designed to follow a distribution that is indistinguishable from…

Signal Processing · Electrical Eng. & Systems 2025-02-25 Matthew R. Ziemann , Christopher A. Metzler

Conventional optical imaging is limited by diffraction, preventing discrimination of closely spaced incoherent sources. Inspired by quantum parameter estimation, this thesis explores spatial-mode demultiplexing (SPADE) as a method to…

Optics · Physics 2025-09-23 Nickolay Erin Titov

We propose a method to track signals from quadrant photodiodes (QPD) in heterodyne laser interferometers that employ digital phase-locked loops for phase readout. Instead of separately tracking the four segments from the QPD and then…

Instrumentation and Detectors · Physics 2020-11-17 Gerhard Heinzel , Miguel Dovale Álvarez , Alvise Pizzella , Nils Brause , Juan José Esteban Delgado

The combination of deep unfolding with vector approximate message passing (VAMP) algorithm, results in faster convergence and higher sparse recovery accuracy than traditional compressive sensing approaches. However, deep unfolding alters…

Signal Processing · Electrical Eng. & Systems 2025-04-15 Haoyun Zhang , Chengyang Zhang , Xueqian Wang , Gang Li , Xiao-Ping Zhang

Fiber-optical networks are a crucial telecommunication infrastructure in society. Wavelength division multiplexing allows for transmitting parallel data streams over the fiber bandwidth, and coherent detection enables the use of…

Signal Processing · Electrical Eng. & Systems 2020-02-19 Lars Lundberg , Mikael Mazur , Ali Mirani , Benjamin Foo , Jochen Schröder , Victor Torres-Company , Magnus Karlsson , Peter A. Andrekson

Grant-free non-orthogonal multiple access has been regarded as a viable approach to accommodate access for a massive number of machine-type devices with small data packets. The sporadic activation of the devices creates a multiuser setup…

Signal Processing · Electrical Eng. & Systems 2023-05-15 Yanna Bai , Wei Chen , Bo Ai , Petar Popovski

We propose a comprehensive scheme for realizing a massive multiple-input multiple-output (MIMO) system with dual-polarized antennas in frequency division duplexing (FDD) mode. Employing dual-polarized elements in a massive MIMO array has…

Information Theory · Computer Science 2020-08-26 Mahdi Barzegar Khalilsarai , Tianyu Yang , Saeid Haghighatshoar , Xinping Yi , Giuseppe Caire

On 3D imaging, light field cameras typically are of single shot, and however, they heavily suffer from low spatial resolution and depth accuracy. In this paper, by employing an optical projector to project a group of single high-frequency…

Image and Video Processing · Electrical Eng. & Systems 2024-04-11 Geyou Zhang , Ce Zhu , Kai Liu , Yipeng Liu

Distributed antennas must be phase-calibrated (phase-synchronized) for certain operations, such as reciprocity-based joint coherent downlink beamforming, to work. We use rigorous signal processing tools to analyze the accuracy of…

Information Theory · Computer Science 2024-01-23 Erik G. Larsson

Free-space optical communication (FSOC) systems offer high-bandwidth and secure communication with minimal capital costs. Adaptive optics (AO) are typically added to these systems to decrease atmospheric channel losses; however, the…

Estimating homography to align image pairs captured by different sensors or image pairs with large appearance changes is an important and general challenge for many computer vision applications. In contrast to others, we propose a generic…

Computer Vision and Pattern Recognition · Computer Science 2021-04-26 Yiming Zhao , Xinming Huang , Ziming Zhang

Our aim is to assess the benefits and limitations of using the redundant visibility information in regular phased array systems for improving the calibration. Regular arrays offer the possibility to use redundant visibility information to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Parisa Noorishad , Stefan J. Wijnholds , Arnold van Ardenne , Thijs van der Hulst

We consider the problem of channel estimation and joint active and passive beamforming for reconfigurable intelligent surface (RIS) assisted millimeter wave (mmWave) multiple-input multiple-output (MIMO) orthogonal frequency division…

Signal Processing · Electrical Eng. & Systems 2022-10-05 Xi Zheng , Jun Fang , Hongwei Wang , Peilan Wang , Hongbin Li

There exists the phase ambiguity problem in the coherent beam combining (CBC) system with centrosymmetric arrays, which means that multiple different piston aberrations may generate the same far-field image. This will cause that the…

Optics · Physics 2021-12-02 H. Jia , J. Zuo , Q. Bao , C. Geng , A. Tang , Y. Luo , Z. Li , J. Jiang , F. Li , F. Zou , X. Yang , Z. Pan , J. Jiang , J. Ren , X. Li

Optical phase-space functions describe spatial and angular information simultaneously; examples include light fields in ray optics and Wigner functions in wave optics. Measurement of phase-space enables digital refocusing, aberration…

Optics · Physics 2017-08-02 Hsiou-Yuan Liu , Jingshan Zhong , Laura Waller

In this work, we introduce DifFoundMAD, a parameter-efficient D-MAD framework that exploits the generalisation capabilities of vision foundation models (FM) to capture discrepancies between suspected morphs and live capture images. In…

Computer Vision and Pattern Recognition · Computer Science 2026-04-21 Lazaro J. Gonzalez-Soler , André Dörsch , Christian Rathgeb , Christoph Busch

In order for telescopes to obtain good and precise images they need to see through atmospheric turbulence. To accomplish this and compensate for atmospheric turbulence we use Adaptive Optics technologies. In this thesis we analyze the…

Instrumentation and Methods for Astrophysics · Physics 2023-10-13 Cesar Laguna

In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Benjamin Pope , Nick Cvetojevic , Anthony Cheetham , Frantz Martinache , Barnaby Norris , Peter Tuthill

For astronomical instruments, accurate knowledge of the optical pointing and coupling are essential to characterize the alignment and performance of (sub-)systems prior to integration and deployment. Ideally, this requires the phase…

Instrumentation and Methods for Astrophysics · Physics 2020-02-11 S. J. C. Yates , K. K. Davis , W. Jellema , J. J. A. Baselmans , A. M. Baryshev