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A Novel Prior-Based Channel Estimation and Activity Detection in Cell-Free mMTC systems

IEEE TRANSACTIONS ON SIGNAL processing 2024年 72卷 5500-5516页

作者： Rajoriya, Anupama Singh, Nakul Budhiraja, Rohit Chaturvedi, Ajit K. IIT Kanpur Dept Elect Engn Kanpur 208016 India Georgia Inst Technol Atlanta GA 30332 USA

We consider the problem of joint channel estimation (CE) and device activity detection (DAD) in the uplink of a cell-free millimeter wave massive multiple-input multiple output (mMIMO) system for massive machine-type communication. We know that the mMIMO channel is spatially correlated, and is sparse in the angular domain. The correlation and sparsity are captured by tailoring a Gaussian prior. This prior is then used to design a centralized variational Bayesian learning (cVBL) algorithm for CE and DAD. The variational approximation in cVBL algorithm reduces its complexity from cubic to linear in terms of devices. We next propose an asynchronous decentralized VBL (adVBL) algorithm, wherein each AP locally estimates its channel from all the devices. The adVBL algorithm is robust to the AP failures, and its complexity is invariant of the number of APs. The adVBL algorithm is developed by reformulating cVBL updates as global optimization problems, and by deriving their local counterparts using the alternating direction method of multipliers. Through extensive numerical studies, we show that the proposed cVBL and adVBL algorithms i) outperform several existing algorithms;ii) require much less pilot overhead;and iii) estimate large-scale fading, unlike the existing ones.

关键词： Approximation algorithms Signal processing algorithms Correlation Channel estimation Antennas Millimeter wave communication Complexity theory Optimization Bayes methods Vectors Decentralized algorithm expectation maximization variational Bayesian learning

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Attack on optical cryptosystems by skip connection networks

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OPTICS EXPRESS 2024年第11期32卷 19424-19437页

作者： Wang, Jiaao Wang, Dongfei Beijing Inst Graph Commun Sch Informat Engn Beijing 102600 Peoples R China Nnchang Inst Technol Nanchang 330044 Jiangxi Peoples R China

optical encryption methods, due to their efficient operation speed and parallel processing capabilities, hold significant importance in securing multidimensional and large -volume data. Enhancing the security of optical cryptosystems from the perspective of cryptanalysis holds significant importance currently. Presently, attack methods against optical encryption are complex, and the effectiveness of these attacks is insufficient. Security analysis solutions face limitations in both breadth and depth. Therefore, this paper proposes an attack on optical cryptosystems based on a skip connection network, demonstrating the susceptibility of optical cryptosystems to attacks based on neural network algorithms. The network model is trained on plaintext-ciphertext pairs, fitting equivalent keys without various additional conditions. It approximates plaintext information in high -dimensional space, directly obtaining corresponding plaintext through ciphertext information, expanding the applicability and enhancing the effectiveness of the attack scheme. Finally, the feasibility and effectiveness of the attack scheme were verified through computer simulations. The experiments indicate that the method proposed in this paper has low computational complexity, wide applicability, produces high -quality decrypted images, and high decipherment accuracy. This provides a universal approach for analyzing the security of various optical cryptosystems from the perspective of chosen plaintext attacks.

关键词： Computer simulation Image encryption Light beams optical encryption optical security Phase retrieval

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Clipping discrete multi-tone for peak-power-constraint IM/DD optical systems

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Science China(information Sciences) 2023年第5期66卷 227-237页

作者： Ji ZHOU Liangchuan LI Jiale HE Xiaofeng LU Yu BO Guanyu WANG Yuanda HUANG Gengchen LIU Yanzhao LU Shecheng GAO Yuanhua FENG Shancheng ZHAO Weiping LIU Changyuan YU Zhaohui LI Department of Electronic Engineering College of Information Science and Technology Jinan University Optical Research Department Huawei Technologies Co. Ltd. Department of Electronic and Information Engineering The Hong Kong Polytechnic University Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen University Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)

High peak-to-average power ratio(PAPR) is a major drawback of discrete multi-tone(DMT) in peak-power-constraint(PPC) intensity-modulation/direct-detection(IM/DD) optical systems. Symmetric clipping operation is a frequently-used and practical method for mitigating the PAPR of the DMT ***, clipping noise is inevitably induced by the symmetric clipping operation, thereby deteriorating the system's performance. In this paper, we study the statistical characteristics of the clipping noise in *** on the statistical characteristics, clipping-noise-cancellation(CNC) algorithms are proposed to mitigate the clipping noise in the clipping DMT systems. Theoretically, the clipping noise can be completely removed using the low-density-parity-check-assisted CNC algorithm(LDPC-assisted CNC algorithm). To verify the superiority of the clipping DMT with the CNC algorithm, we conduct an experiment with a50 Gb/s DMT system using 10G-class commercial devices for the scenario of PPC passive optical *** receiver sensitivity of the clipping DMT system with the CNC algorithm can reach-24 d Bm at a 20%soft-decision forward-error-correction limit, which is 2.5 d B higher than that of the DMT system without clipping operation. The clipping operation and the CNC algorithm are added after the original digital signal processing, thereby demonstrating the potential to efectively overcome the drawback in DMT signals and other high-PAPR signals.

关键词： discrete multi-tone peak-to-average power ratio peak-power constraint clipping-noise cancellation intensity-modulation/direct-detection optical systems

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Distributed intelligence for pervasive optical network telemetry

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JOURNAL OF optical COMMUNICATIONS AND NETWORKING 2023年第9期15卷 676-686页

作者： Velasco, Luis Gonzalez, Pol Ruiz, Marc Univ Politecn Cataluna Barcelona Spain

optical network automation and failure management require measuring the status and the performance of the different network devices to anticipate any degradation and ensure the quality of the provided services, i.e., optical connectivity. Such pervasive network telemetry entails collecting large amounts of measurements and events from different sources and with very fine granularity, which given the amount and variety of telemetry sources and the size of each measurement and event, imposes requirements that are hard to achieve without large investments. In this paper, we analyze the main limitations of telemetry architectures relying exclusively on centralized systems for data analysis and propose an architecture with distributed intelligence. Data aggregation techniques, especially conceived for optical network telemetry, are presented with the objective of reducing data dimensionality. Illustrative results from our experimental telemetry system reveal a reduction of 3 orders of magnitude in terms of total data volume without introducing significant error and processing delay and, more importantly, helping network automation algorithms to identify meaningful changes in the network status.

关键词： Telemetry optical variables measurement Pollution measurement optical fiber networks Computer architecture Adaptive optics optical receivers

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Research on SMA motor modelling and control algorithm for optical image stabilization

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MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOsystems-information STORAGE AND processing systems 2025年第6期31卷 1381-1400页

作者： Li, Chen Qu, Yingmin Song, Zhengxun Liu, Xinliang Liu, Weiwen Changchun Univ Sci & Technol Int Res Ctr Nano Handling & Mfg China Changchun 130022 Jilin Peoples R China Changchun Univ Sci & Technol Zhongshan Inst Zhongshan 528437 Guangdong Peoples R China Changchun Univ Sci & Technol Sch Elect & Informat Engn Changchun 130022 Jilin Peoples R China

Cameras play an increasingly important role in mobile devices and intelligent systems. With the development of technology, the resolution of the camera continues to improve and the images become much clearer. However, image quality is easily affected by lens shake. optical stabilization technology improves the shooting stability as well as image quality of mobile devices by overcoming image blur which is caused by lens shake. In the current camera modules of smart devices, the voice coil motor (VCM) drives the lens movement. However, the traditional VCMs contain permanent magnets, thus generating stray magnetic fields and affecting the quality of captured images. Compared with VCM technology, shape memory alloy (SMA) motors driven by shape memory alloys have the advantages, such as lighter weight, higher accuracy, greater thrust, and lower energy consumption. But there are still some issues with the current SMA motors. To begin with, there is a control problem of SMA wire, and the current control algorithms are difficult to achieve high-precision control of SMA wire. What's more, the strain range of SMA wires used in current SMA motors is limited, so their application in certain fields are restricted. A SMA motor with a larger shrinkage of SMA wire was designed, which could be used in larger lenses and whose application range was extended. Given the hysteresis effect of SMA, a Hammerstein-like model was established to describe the dynamic hysteresis characteristics of SMA. The Prandtl Ishlinskii model was used to describe the static hysteresis model of SMA, and the Nonlinear AutoRegressive network with eXogenous inputs (NARX) model was used to describe the dynamic model of SMA and predict its properties. A composite control scheme based on inverse compensation was designed to eliminate the dynamic hysteresis phenomenon of SMA, using the PI inverse model as the feed-forward controller and BP-FOPID as the feedback controller. In a gesture to address the problem of mul

关键词： Permanent magnets

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Smart Machine Vision for Universal Spatial-Mode Reconstruction

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IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING systems 2025年 PP卷 PP页

作者： Huerta-Morales, Jose D. You, Chenglong Magana-Loaiza, Omar S. Dong, Shi-Hai Leon-Montiel, Roberto de J. Quiroz-Juarez, Mario A. Univ Nacl Autonoma Mexico Inst Ciencias Nucl Mexico City 04510 Mexico Louisiana State Univ Dept Phys & Astron Quantum Photon Lab Baton Rouge LA 70803 USA Huzhou Univ Res Ctr Quantum Phys Huzhou 310003 Peoples R China UPALM Inst Politecn Nacl Lab Cienciasde Informac Cuant CIC Mexico City 07700 Mexico Univ Nacl Autonoma Mexico Ctr Fis Aplicada & Tecnol Avanzada Queretaro 76230 Mexico

Structured light beams, in particular, those carrying orbital angular momentum (OAM), have gained a lot of attention due to their potential for enlarging the transmission capabilities of communication systems. However, the use of OAM-carrying light in communications faces two major problems, namely distortions introduced during propagation in disordered media, such as the atmosphere or optical fibers, and the large divergence that high-order OAM modes experience. While the use of nonorthogonal modes may offer a way to circumvent the divergence of high-order OAM fields, artificial intelligence (AI) algorithms have shown promise for solving the mode-distortion issue. Unfortunately, current AI-based algorithms make use of large-amount data-handling protocols that generally lead to large processing time and high power consumption. Here, we show that a low-power, low-cost image sensor can act as an artificial neural network that simultaneously detects and reconstructs distorted OAM-carrying beams. We demonstrate the capabilities of our device by reconstructing (with a 95% efficiency) individual Vortex, Laguerre-Gaussian (LG), and Bessel modes, as well as hybrid (nonorthogonal) coherent superpositions of such modes. Our work provides a potentially useful basis for the development of low-power-consumption, light-based communication devices.

关键词： Accuracy Laser beams Image reconstruction optical distortion optical fiber networks optical beams Convolutional neural networks optical fibers Deep learning Crosstalk Artificial intelligence (AI) neural networks smart machine-vision device spatial-mode reconstruction

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Advances in Wearable Brain-Computer Interfaces From an Algorithm-Hardware Co-Design Perspective

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IEEE TRANSACTIONS ON CIRCUITS AND systems ii-EXPRESS BRIEFS 2022年第7期69卷 3071-3077页

作者： Byun, Wooseok Je, Minkyu Kim, Ji-Hoon SAPEON Korea Architecture Team Seongnam 13486 South Korea Korea Adv Inst Sci & Technol Sch Elect Engn Daejeon 34141 South Korea Ewha Womans Univ Dept Elect & Elect Engn Smart Factory Multidisciplinary Program Seoul 03760 South Korea

Brain-computer interface (BCI), a communication technology between brain and computer developed for a long time since the 1970s, can be incorporated into wearable devices by developing powerful signal processing algorithms and semiconductor technologies. For a satisfactory user experience based on BCI, high information transfer rate and low power consumption should be considered together without losing accuracy. Although many existing BCI algorithms have been mainly focused solely on the accuracy, their deployment on wearable devices is not straightforward due to the limited hardware resources and computational capabilities. This tutorial summarizes recent advances in wearable BCI algorithms and hardware implementations from an algorithm-hardware co-design perspective and discusses future directions.

关键词： Signal processing algorithms Partitioning algorithms Hardware Wearable computers Recording Visualization Signal processing Brain-computer interface (BCI) algorithm-hardware co-design domain-specific architecture deep learning accelerator linear algebra accelerator

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Design of photovoltaic radio energy transmission system based on NSGA-ii

Design of photovoltaic radio energy transmission system base...

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2024 International Conference on Signal processing and Communication Security, ICSPCS 2024

作者： Zhou, Jiacheng Ma, Jun Wang, Hongxiang Chen, Bohang Institute of Computer Science Qinghai Normal University Qinghai China Institute of Physics and Electronic Information Engineering Qinghai Normal University Xining Qinghai China

ISBN: (纸本)9781510681699

In order to efficiently apply Wireless Power Transfer (WPT) technology in photovoltaic (PV) systems, mathematical modeling and mechanism analysis of Magnetic Coupling Resonant Wireless Power Transfer (MCR-WPT) systems were conducted. By employing the multi-objective genetic algorithm (NSGA-ii) and an adjustable coupling distance LCC-S topology, the reliability of power supply was ensured. The results demonstrate stable charging efficiency, strong adaptability, and high potential for widespread application. © 2024 SPIE.

关键词： Genetic algorithms

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Interferometer response characterization algorithm for multi-aperture Fabry-Perot imaging spectrometers

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OPTICS EXPRESS 2023年第14期31卷 23066-23085页

作者： Picone, Daniele Gousset, Silvere Dalla Mura, Mauro Ferrec, Yann Le Coarer, Etienne Univ Grenoble Alpes GIPSA lab CNRS Grenoble INP F-38000 Grenoble France Univ Grenoble Alpes CNRS IPAG F-38000 Grenoble France Inst Univ France IUF F-75005 Paris France Off Natl Etud & Rech Aerosp DOTA BP 80100Chemin Huniere F-91123 Palaiseau France

In recent years, the demand for hyperspectral imaging devices has grown significantly, driven by their ability of capturing high-resolution spectral information. Among the several possible optical designs for acquiring hyperspectral images, there is a growing interest in interferometric spectral imaging systems based on division of aperture. These systems have the advantage of capturing snapshot acquisitions while maintaining a compact design. However, they require a careful calibration to operate properly. In this work, we present the interferometer response characterization algorithm (IRCA), a robust three-step procedure designed to characterize the transmittance response of multi-aperture imaging spectrometers based on the interferometry of Fabry-Perot. Additionally, we propose a formulation of the image formation model for such devices suitable to estimate the parameters of interest by considering the model under various regimes of finesse. The proposed algorithm processes the image output obtained from a set of monochromatic light sources and refines the results using nonlinear regression after an ad-hoc initialization. Through experimental analysis conducted on four different prototypes from the Image SPectrometer On Chip (ImSPOC) family, we validate the performance of our approach for characterization. The associated source code for this paper is available from Zenodo (http://***/10.5281/zenodo.7978514).& COPY;2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Hyperspectral imaging Image processing algorithms Imaging systems Medical imaging optical components optical design

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Intelligent electronic-optical sensor for information-measurement system of detection and identification of ground and aerodynamic objects

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SEMICONDUCTOR PHYSICS QUANTUM ELECTRONICS & OPTOELECTRONICS 2022年第2期25卷 219-226页

作者： Lepikh, Ya, I Santoniy, V., I Budiyanskaya, L. M. Yanko, V., I Balaban, A. P. Odesa II Mechnikov Univ Minist Educ & Sci Interdept Sci & Educ Physicotech Ctr Odesa Ukraine Odesa II Mechnikov Univ Natl Acad Sci Ukraine Odesa Ukraine

This work describes an original intelligent electronic-optical (laser) sensor (EOS) operating in the infrared range for systems that detect ground and aerodynamic objects and send control commands to the executive devices of portable information-measurement systems using specified algorithms. EOS proposed here differs from the known analogues by its ability of early detection and recognition of high-speed special machinery objects and small-sized unmanned aircrafts. EOS generates and sends probing optical pulses in the direction of a monitored high- speed object, processes the reflected location signal and retrieves the object coordinates and motion parameters. The classification features of the object are determined from the parameters of optical location signal used for object identification with the account the specific nature of optical location information systems.

关键词： electronic-optical sensor optical location signal algorithm information-measurement system

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