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Affine Frequency Division Multiplexing (AFDM) has been proposed as an effective waveform for achieving the full diversity of doubly-dispersive (delay-Doppler) channels. While this property is closely related to range and velocity estimation…

Information Theory · Computer Science 2025-11-07 Ali Bemani , Nassar Ksairi , Marios Kountouris

Affine frequency division multiplexing (AFDM) and orthogonal AFDM access (O-AFDMA) are promising techniques based on chirp signals, which are able to suppress the performance deterioration caused by Doppler shifts in high-mobility…

Information Theory · Computer Science 2024-05-07 Yiwei Tao , Miaowen Wen , Yao Ge , Tianqi Mao , Lixia Xiao , Jun Li

We present an approach for improving spatial frequency sampling in active incoherent millimeter-wave (AIM) imaging systems using frequency diversity. AIM imaging relies on active transmission of spatio-temporally incoherent signals to…

Signal Processing · Electrical Eng. & Systems 2025-03-12 Jorge R. Colon-Berrios , Jeffrey A. Nanzer

Affine frequency division multiplexing (AFDM) has recently emerged as a resilient waveform candidate for high-mobility next-generation wireless systems. However, current literature mostly focuses on discrete time (DT) models, often…

Signal Processing · Electrical Eng. & Systems 2026-03-06 Michele Mirabella , Hyeon Seok Rou , Pasquale Di Viesti , Giuseppe Thadeu Freitas de Abreu , Giorgio Matteo Vitetta

This paper proposes an integrated sensing and communications (ISAC) system based on affine frequency division multiplexing (AFDM) waveform. To this end, a metric set is designed according to not only the maximum tolerable delay/Doppler, but…

Signal Processing · Electrical Eng. & Systems 2025-02-03 Yuanhan Ni , Peng Yuan , Qin Huang , Fan Liu , Zulin Wang

Affine frequency division multiplexing (AFDM) has recently emerged as an excellent backward-compatible 6G waveform. In this paper, we study matched filtering (MF) assisted channel estimation (CE) for AFDM systems in complex doubly selective…

Signal Processing · Electrical Eng. & Systems 2026-02-18 Xiangjun Li , Zilong Liu , Zhengchun Zhou , Pingzhi Fan

The time-domain technique for impedance spectroscopy consists of computing the excitation voltage and current response Fourier images by fast or discrete Fourier transformation and calculating their relation. Here we propose an alternative…

Data Analysis, Statistics and Probability · Physics 2017-12-14 Daniil D. Stupin , Sergei V. Koniakhin , Nikolay A. Verlov , Michael V. Dubina

The quality of energy produced in renewable energy systems has to be at the high level specified by respective standards and directives. The estimation accuracy of grid signal parameters is one of the most important factors affecting this…

Systems and Control · Computer Science 2016-01-05 Józef Borkowski , Dariusz Kania

The Stroke Minimization algorithm developed at the Princeton High Contrast Imaging Laboratory has proven symmetric dark hole generation using minimal stroke on two deformable mirrors (DM) in series. The windowed approach to Stroke…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Tyler D. Groff , N. Jeremy Kasdin , Alexis Carlotti , A J Eldorado Riggs

The concept of the frequency diverse reconfigurable intelligent surface (FD-RIS) technology has been introduced, which can enable simultaneous implementation of distance-angle beamforming in far-field communication scenarios. In order to…

Information Theory · Computer Science 2025-12-02 Han Xiao , Xiaoyan Hu , Wenjie Wang , Kai-Kit Wong , Kun Yang , Shi Jin

Spectrometry is a general physical-analysis approach for investigating light-matter interactions. However, the complex designs of existing spectrometers render them resistant to simplification and miniaturization, both of which are vital…

Digital correlated double sampling (DCDS), a readout technique for charge-coupled devices (CCD), is gaining popularity in astronomical applications. By using an oversampling ADC and a digital filter, a DCDS system can achieve a better…

Instrumentation and Methods for Astrophysics · Physics 2015-11-23 Cristobal Alessandri , Angel Abusleme , Dani Guzman , Ignacio Passalacqua , Enrique Alvarez-Fontecilla , Marcelo Guarini

Affine frequency division multiplexing (AFDM) is a novel modulation technique based on chirp signals that has been recently proposed as an effective solution for highly reliable communications in high-mobility scenarios. In this paper, we…

Signal Processing · Electrical Eng. & Systems 2024-11-18 Yiwei Tao , Miaowen Wen , Yao Ge , Jun Li , Ertugrul Basar , Naofal Al-Dhahir

Millimeter wave communications require multibeam beamforming in order to utilize wireless channels that suffer from obstructions, path loss, and multi-path effects. Digital multibeam beamforming has maximum degrees of freedom compared to…

The Current Mirror (CM) is a basic building block commonly used in analogue and mixed-signal integrated circuits. Its significance lies in its ability to replicate and precisely regulate the current, making it crucial in various…

Signal Processing · Electrical Eng. & Systems 2025-02-24 Lua Ying Qian , Chia Chao Kang , Tan Jian Ding , Mohammad Arif Sobhan Bhuiyan , Khairun Nisa Minhad , Mahdi H. Miraz

We consider realistic satellite communications systems for broadband and broadcasting applications, based on frequency-division-multiplexed linear modulations, where spectral efficiency is one of the main figures of merit. For these…

Information Theory · Computer Science 2013-01-18 Amina Piemontese , Andrea Modenini , Giulio Colavolpe , Nader Alagha

Digital acquisition of high bandwidth signals is particularly challenging when Nyquist rate sampling is impractical. This has led to extensive research in sub-Nyquist sampling methods, primarily for spectral and sinusoidal frequency…

Information Theory · Computer Science 2024-09-26 Ruiming Guo , Yuliang Zhu , Ayush Bhandari

We present the development and characterization of a generic, reconfigurable, low-cost ($<$ 350 USD) software-defined digital receiver system (DRS) for temporal correlation measurements in atomic spin ensembles. We demonstrate the use of…

Instrumentation and Detectors · Physics 2021-01-26 V. Mugundhan , Maheswar Swar , Subhajit Bhar , Saptarishi Chaudhuri

We have constructed a Fourier-transform spectrometer (FTS) operating between 50 and 330 GHz with minimum volume (355 x260 x64 mm) and weight (13 lbs) while maximizing optical throughput (100 $\mathrm{mm}^2$ sr) and optimizing the spectral…

Instrumentation and Methods for Astrophysics · Physics 2019-09-04 Zhaodi Pan , Mira Liu , Ritoban Basu Thakur , Bradford A. Benson , Dale J. Fixsen , Hazal Goksu , Eleanor Rath , Stephan S. Meyer

This work presents a fully-digital high-accuracy real-time calibration procedure for frequency and time alignment of open-loop wirelessly coordinated coherent distributed antenna array (CDA) modems, enabling radio frequency (RF) phase…

Signal Processing · Electrical Eng. & Systems 2025-12-02 Jason M. Merlo , Samuel Wagner , John Lancaster , Jeffrey A. Nanzer