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CSI-Free Position Optimization for Movable Antenna Communication Systems: A Black-Box Optimization Approach

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arXiv 2024年

作者： Zeng, Xianlong Fang, Jun Wang, Bin Ning, Boyu Li, Hongbin National Key Laboratory of Wireless Communications University of Electronic Science and Technology of China Chengdu611731 China Department of Electrical and Computer Engineering Stevens Institute of Technology HobokenNJ07030 United States

Movable antenna (MA) is a new technology which leverages local movement of antennas to improve channel qualities and enhance the communication performance. Nevertheless, to fully realize the potential of MA systems, complete channel state information (CSI) between the transmitter-MA and the receiver-MA is required, which involves estimating a large number of channel parameters and incurs an excessive amount of training overhead. To address this challenge, in this paper, we propose a CSI-free MA position optimization method. The basic idea is to treat position optimization as a black-box optimization problem and calculate the gradient of the unknown objective function using zeroth-order (ZO) gradient approximation techniques. Simulation results show that the proposed ZO-based method, through adaptively adjusting the position of the MA, can achieve a favorable signal-to-noise-ratio (SNR) using a smaller number of position measurements than the CSI-based approach. Such a merit makes the proposed algorithm more adaptable to fast-changing propagation channels. Copyright © 2024, The Authors. All rights reserved.

关键词： Channel estimation

Single-Photon Emitters in Aluminum Nitride by Zr ion Implantation

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Single-Photon Emitters in Aluminum Nitride by Zr ion Implant...

2023 Conference on Lasers and Electro-Optics, CLEO 2023

作者： Senichev, Alexander Martin, Zachariah O. Wang, Yongqiang Htoon, Han Lagutchev, Alexei S. Boltasseva, Alexandra Shalaev, Vladimir M. School of Electrical and Computer Engineering Birck Nanotechnology Center Purdue Quantum Science and Engineering Institute Purdue University West LafayetteIN47907 United States OakRidgeTN37931 United States Ion Beam Materials Laboratory Materials Science and Technology Division Los Alamos National Laboratory Los AlamosNM87545 United States Center for Integrated Nanotechnologies Materials Physics and Applications Division Los Alamos National Laboratory Los AlamosNM87545 United States

We report on the generation of single-photon emitters in aluminum nitride films through Zr-ion implantation, which was predicted to form optically addressable spin defects. We studied implantation conditions, post-imp... 详细信息

ISBN: (纸本)9781957171258

关键词： Ion implantation

An Unstructured Body-of-Revolution Electromagnetic Particle-in-Cell Algorithm with Radial Perfectly Matched Layers and Dual Polarizations

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arXiv 2024年

作者： Na, Dong-Yeop Teixeira, Fernando L. Omelchenko, Yuri A. Department of Electrical Engineering Pohang University of Science and Technology Pohang37673 Korea Republic of ElectroScience Laboratory Department of Electrical and Computer Engineering The Ohio State University ColumbusOH43212 United States Trinum Research Inc. San DiegoCA92126 United States

A novel electromagnetic particle-in-cell algorithm has been developed for fully kinetic plasma simulations on unstructured (irregular) meshes in complex body-of-revolution geometries. The algorithm, implemented in the BORPIC++ code, utilizes a set of field scalings and a coordinate mapping, reducing the Maxwell field problem in a cylindrical system to a Cartesian finite element Maxwell solver in the meridian plane. The latter obviates the cylindrical coordinate singularity in the symmetry axis. The choice of an unstructured finite element discretization enhances the geometrical flexibility of the BORPIC++ solver compared to the more traditional finite difference solvers. Symmetries in Maxwell's equations are explored to decompose the problem into two dual polarization states with isomorphic representations that enable code reuse. The particle-in-cell scatter and gather steps preserve charge-conservation at the discrete level. Our previous algorithm (BORPIC+) discretized the E and B field components of TEφ and TMφ polarizations on the finite element (primal) mesh [1, 2]. Here, we employ a new field-update scheme. Using the same finite element (primal) mesh, this scheme advances two sets of field components independently: (1) E and B of TEφ polarized fields, (Ez,Eρ,Bφ) and (2) D and H of TMφ polarized fields, (Dφ,Hz,Hρ). Since these field updates are not explicitly coupled, the new field solver obviates the coordinate singularity, which otherwise arises at the cylindrical symmetric axis, ρ = 0 when defining the discrete Hodge matrices (generalized finite element mass matrices). A cylindrical perfectly matched layer is implemented as a boundary condition in the radial direction to simulate open space problems, with periodic boundary conditions in the axial direction. We investigate effects of charged particles moving next to the cylindrical perfectly matched layer. We model azimuthal currents arising from rotational motion of charged rings, which produce TMφ polarized

关键词： Maxwell equations

Multiple Stable Oscillators Referenced to the Same Multimode AlN/Si MEMS Resonator with Mode-Dependent Phase Noise and Frequency Stability

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Multiple Stable Oscillators Referenced to the Same Multimode...

International Electron Devices Meeting (IEDM)

作者： Tahmid Kaisar S M Enamul Hoque Yousuf Jaesung Lee Afzaal Qamar Mina Rais-Zadeh Soumyajit Mandal Philip X.-L. Feng Electrical & Computer Engineering University of Florida Gainesville FL USA Electrical & Computer Engineering University of Michigan Ann Arbor MI USA Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA Brookhaven National Laboratory Upton NY USA

ISBN: (纸本)9781665489607

We report on the first experimental demonstration of multiple self-sustaining feedback oscillators referenced to a single multimode resonator, using piezoelectric aluminum nitride on silicon (AlN/Si) microelectromechanical systems (MEMS) technology. Integrated piezoelectric transduction enables efficient readout of three resonance modes of the same AlN/Si MEMS resonator, at 10MHz, 30MHz, and 65MHz with quality (Q) factors of 18600, 4350, 4230, respectively. Three stable self-sustaining oscillators are built, each referenced to one of these high-Q modes, and their mode-dependent phase noise and frequency stability (Allan deviation) are measured and analyzed. The 10, 30 and 65MHz oscillators exhibit low phase noise of -114, -100 and -105dBc/Hz at 1kHz offset frequency, respectively. The 65MHz oscillator yields excellent Allan deviation of $4\times 10^{-9}$ and $2\times 10^{-7}$ at ls and 1000s averaging time, respectively. The 10MHz oscillator’s low phase noise holds strong promise for clock and timing applications. The three oscillators’ overall excellent performance also suggests suitability for multimode resonant sensing and tracking. This work also elucidates mode dependency in oscillator noise and stability, on key attributes of mode-engineerable resonators.

关键词： Phase noise Micromechanical devices Temperature measurement Phase measurement Resonant frequency Stability analysis Sensors

NOMA-Empowered Federated Learning for Enhancing Uplink Efficiency in Wireless Networks

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NOMA-Empowered Federated Learning for Enhancing Uplink Effic...

International Conference on Ubiquitous Information Management and Communication (IMCOM)

作者： Hung Hoang Le Toan-Van Nguyen Tung Dinh Van Tien Hoa Nguyen Hyunseung Choo School of Electrical and Electronic Engineering Hanoi University of Science and Technology Hanoi Vietnam School of Computer Science and Engineering International University HCM Vietnam Vietnam National University HCM Vietnam Superintelligence Laboratory Sungkyunkwan University Suwon Korea

This paper proposes an uplink non-orthogonal multiple access (NOMA)-assisted federated learning (FL) framework to enhance the stable and accurate convergence in wireless networks. In this system, clients upload their local models securely to the base station through uplink NOMA to improve the uplink transmissions efficiency. We mathematically formulate the total latency optimization problem, taking into account the quality-of-service (QoS) requirements for clients, the power allocation at the base station (BS), and the frequency considerations. Simulation results show the that of the proposed FL framework achieves an 11% higher test accuracy and reduces latency by 25% compared to FedAvg and FedProx.

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Transi-Net: An Explainable Deep Learning Model Ensemble For Prostate's Transition Zone Segmentation

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Transi-Net: An Explainable Deep Learning Model Ensemble For ...

IEEE Symposium on Bioinformatics and Bioengineering (BIBE)

作者： Dimitrios I. Zaridis Eugenia Mylona Nikolaos S. Tachos Charalampos Kalantzopoulos Kostas Marias Manolis Tsiknakis Dimitrios D. Koutsouris George K. Matsopoulos Dimitrios I. Fotiadis Biomedical Engineering Laboratory School of Electrical & Computer Engineering and Biomedical Research Institute National Technical University of Athens and FORTH Athens & Ioannina Greece Biomedical Research Institute FORTH Ioannina Greece Computational Biomedicine Laboratory FORTH Heraklion Greece Biomedical Engineering Laboratory School of Electrical & Computer Engineering National Technical University of Athens Athens Greece Biomedical Research Institute and Unit of Medical Technology and Intelligent Information Systems FORTH and University of Ioannina Ioannina Greece

The identification of the location of prostate cancer is of paramount importance for improved treatment. This process is strictly bonded with the accurate segmentation of the prostate gland and its zones, on MR images. In the present study, an ensemble of 3 deep learning models along with a Meta-learner module able to refine the outcomes of the models, is proposed (Transi-Net) to segment the prostate's transition zone. A method to quantify the model's uncertainty is introduced to measure the confidence of an architecture with respect to its final decision. The backbone of Transi-Net consist the original U-net, Dense2U-net and Bridged U-net models. The proposed model showcased significant improvement in comparison with its base components as well as an independent model, the USE-Net, while it was proven more confident about its decision. The proposed model resulted in an improvement of 5%, 3%, 3% and 4% for Sensitivity, Balanced Accuracy, Dice Score and Rand Error Index respectively, compared to the second best, USE-Net.

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Iterative Equalization of CPM With Unitary Approximate Message Passing

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arXiv 2024年

作者： Liu, Zilong Song, Yi Guo, Qinghua Sun, Peng Gong, Kexian Wang, Zhongyong The School of Electrical and Information Engineering Zhengzhou University Zhengzhou450001 China The Key Laboratory of Grain Information Processing and Control Ministry of Education The College of Information Science and Engineering Henan University of Technology Zhengzhou450001 China The School of Electrical Computer and Telecommunications Engineering University of Wollongong WollongongNSW2522 Australia

Continuous phase modulation (CPM) has extensive applications in wireless communications due to its high spectral and power efficiency. However, its nonlinear characteristics pose significant challenges for detection in frequency selective fading channels. This paper proposes an iterative receiver tailored for the detection of CPM signals over frequency selective fading channels. This design leverages the factor graph framework to integrate equalization, demodulation, and decoding functions. The equalizer employs the unitary approximate message passing (UAMP) algorithm, while the unitary transformation is implemented using the fast Fourier transform (FFT) with the aid of a cyclic prefix (CP), thereby achieving low computational complexity while with high performance. For CPM demodulation and channel decoding, with belief propagation (BP), we design a message passing-based maximum a posteriori (MAP) algorithm, and the message exchange between the demodulator, decoder and equalizer is elaborated. With proper message passing schedules, the receiver can achieve fast convergence. Simulation results show that compared with existing turbo receivers, the proposed receiver delivers significant performance enhancement with low computational complexity. Copyright © 2024, The Authors. All rights reserved.

关键词： Fast Fourier transforms

Lymphocyte-Infiltrated Periportal Region Detection With Structurally-Refined Deep Portal Segmentation and Heterogeneous Infiltration Features

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IEEE Open Journal of Engineering in Medicine and Biology

IEEE Open Journal of engineering in Medicine and Biology 2024年 5卷 261-270页

作者： Tsai, Hung-Wen Chiou, Chien-Yu Yang, Wei-Jong Hsieh, Tsan-An Chen, Cheng-Yi Hsu, Che-Wei Lin, Yih-Jyh Hsieh, Min-En Yeh, Matthew M. Chen, Chin-Chun Shen, Meng-Ru Chung, Pau-Choo National Cheng Kung University Department of Pathology National Cheng Kung University Hospital College of Medicine Tainan701 Taiwan National Cheng Kung University Department of Electrical Engineering Tainan701 Taiwan National Chin-Yi University of Technology Department of Artificial Intelligence and Computer Engineering Taichung411030 Taiwan National Cheng Kung University Institute of Computer and Communication Engineering Tainan701 Taiwan National Cheng Kung University College of Medicine Department of Cell Biology and Anatomy Tainan701 Taiwan National Cheng Kung University Department of Surgery National Cheng Kung University Hospital College of Medicine Tainan701 Taiwan University of Washington School of Medicine Department of Laboratory Medicine and Pathology SeattleWA98195 United States National Cheng Kung University Department of Statistics Tainan701 Taiwan National Cheng Kung University Department of Pharmacology National Cheng Kung University Hospital College of Medicine Tainan701 Taiwan

Goal: The early diagnosis and treatment of hepatitis is essential to reduce hepatitis-related liver function deterioration and mortality. One component of the widely-used Ishak grading system for the grading of periportal interface hepatitis is based on the percentage of portal borders infiltrated by lymphocytes. Thus, the accurate detection of lymphocyte-infiltrated periportal regions is critical in the diagnosis of hepatitis. However, the infiltrating lymphocytes usually result in the formation of ambiguous and highly-irregular portal boundaries, and thus identifying the infiltrated portal boundary regions precisely using automated methods is challenging. This study aims to develop a deep-learning-based automatic detection framework to assist diagnosis. Methods: The present study proposes a framework consisting of a Structurally-REfined Deep Portal Segmentation module and an Infiltrated Periportal Region Detection module based on heterogeneous infiltration features to accurately identify the infiltrated periportal regions in liver Whole Slide Images. Results: The proposed method achieves 0.725 in F1-score of lymphocyte-infiltrated periportal region detection. Moreover, the statistics of the ratio of the detected infiltrated portal boundary have high correlation to the Ishak grade (Spearman's correlations more than 0.87 with p-values less than 0.001) and medium correlation to the liver function index aspartate aminotransferase and alanine aminotransferase (Spearman's correlations more than 0.63 and 0.57 with p-values less than 0.001). Conclusions: The study shows the statistics of the ratio of infiltrated portal boundary have correlation to the Ishak grade and liver function index. The proposed framework provides pathologists with a useful and reliable tool for hepatitis diagnosis. © 2020 IEEE.

关键词： Feature extraction

Triangular cross-section grating couplers for integrated quantum nanophotonic hardware in silicon carbide

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arXiv 2024年

作者： Saha, Pranta Majety, Sridhar Dhuey, Scott Radulaski, Marina Electrical and Computer Engineering Department University of California DavisCA95616 United States The Molecular Foundry Lawrence Berkeley National Laboratory 1 Cyclotron Rd BerkeleyCA94720 United States

Triangular cross-section nanodevices are among the leading approaches for integrating color centers with photonics for applications in quantum information processing. We design periodic and aperiodic fishbone triangular grating couplers in silicon carbide. We optimize the designs for achieving up to ∼ 31% collection efficiency from color center integrated triangular devices to a microscopy system. Using an ion beam angle etching process, we demonstrate proof-of-principle fabrication of the designed devices for future implementation in wafer-scale quantum nanophotonics. © 2024, CC BY.

关键词： Nanophotonics