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IET International Radar Conference 2018, IRC 2018

作者： Gao, Lu Liu, Li Cao, Yang Wang, Shangyue You, Shixun National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China DFH Satellite Co. Ltd Beijing China Harbin Engineering University 145 Nantong Street Nangang District Harbin China

Strong adaptive radar, such as cognitive radar (CNR), can perform various missions while ensuring its own security in electronic warfare, via detecting environments and changing the radar parameters in real time. Unfortunately, most of the current military countermeasures, such as jamming-based electronic countermeasures, have rarely been related to jamming for CNR. Since the behaviours of radar in the traditional design of the jammer-radar scenario are always static, it is easy to create a subjective or local optimal jamming effect. In order to dynamically analyse the execution process of a complete jamming radar mission, this work establishes an equivalent attack-defence game in which the radar is regarded as a defence decision agent, and the jammer is an attack decision agent. The attributes of the game's players, the rules of the game, and the conditions for the end of the game are set clearly by setting reasonable parameters. After searching for antagonism strategies by exhaustive method, it can be found that the survivability of the predictive cognitive jamming is much stronger than that of the normal jamming based on real-time sampling data of radars. This conclusion is demonstrated through a 1 ms simulation of the game process. © This is an open access article published by the IET under the Creative Commons Attribution License (http://***/licenses/by/3.0/)

关键词： Jamming

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Adaptive feed-forward control for seeker based on the disturbance observer

Adaptive feed-forward control for seeker based on the distur...

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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Xin Liu Zhenhong Niu Yi Shu Lian Xue Mingchao Zhu National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences

In order to improve the tracking and stabilization performance, a control method combining disturbance observer and adaptive feed-forward control using parameterization is proposed for seeker stabilized platforms. The system identification algorithm is used to identify dynamic model of the true plant. Then the discrete-time disturbance observer is designed. The feedback loop controller is designed using pole-placement techniques. The recursive least square (RLS) adaptive filter is used to build the inverse model of the feedback control loop and in this way, the feed-forward control is constructed. The adaptive filter and the feedback loop constitute a control scheme with two degrees-of-freedom (DOF). Tracking experiments conducted on velocity command inputs verify the validity of the adaptive feed-forward controller. Experimental results show that this method responses quickly to commands. For a sinusoidal signal at the frequency of 30Hz, the adaptive feed-forward controller can obtain an amplitude response without attenuation and the phase lag is reduced to 11° in contrast with the feedback control whose phase lag is 60°. This method significantly improves the transient performance and is superior to the feedback control alone.

关键词： Adaptive filters Feedback control Disturbance observers Feedforward systems Low pass filters Tracking loops Stability analysis

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A Direct Position Determination Method for Four-station TDOA Location System

A Direct Position Determination Method for Four-station TDOA...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Sun-Rui Qi Chen-Shun Yuan Bai-Jin Liang Gao-Lu Li-Hu Sun-Heng BEIJING INSTITUTE OF SPACE LONG MARCH VEHICLE National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

Aiming at the four-station networked TDOA (Time Difference of Arrival) localization system, a direct location method based on electronic elevation map search is proposed, the Geometric Dilution Precision (GDOP) is derived, and the factors affecting the location accuracy are analyzed. The location method under real conditions is also simulated, and its feasibility is demonstrated, which provides a new engineering method for networked TDOA location.

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An Improved Adaptive Pulse Compression Algorithm Based on Linear Frequency Modulation Signal

An Improved Adaptive Pulse Compression Algorithm Based on Li...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Jinliang Bai Peng Qin Hu Li Ran Zhang Xinyu Zhang National key laboratory of science and technology on test physics and numerical mathematics Beijing Institute of Space Long March Vehicle Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

In this paper, the radar signal is optimized based on the pulse compression repair (PCR) algorithm, which mainly reduces the computational amount to makes it more advantageous to achieve. The main idea is to implement PCR in a parallel way. The method of implementing parallelism is well known, that is, the signal is segmented, and different segmentation methods can be adopted according to different signal models. In this paper, the chirp signal is mainly processed by decimation and segmentation, and some intrinsic benefits of the performance and computational balance of the proposed method are discussed.

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Broadband Dual-Polarized Antenna with Enhanced Front-To-Back Ratio Using Meta-surface

Broadband Dual-Polarized Antenna with Enhanced Front-To-Back...

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Asia-Pacific Conference on Microwave

作者： Pei Zheng Yuwei Qiu Jinliang Bai Ziwei Xu Xin Liu Jiaqi Liu Jun Li Shuo Zhang Hailiang Zhu Gao Wei National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China Northwestern Polytechnical University Xi'an Shaanxi China

ISBN: (数字)9781728135175

ISBN: (纸本)9781728135182

A novel broadband dual-polarized dipole antenna with enhanced front-to-back ratio is proposed. By placing metasurface around the radiators, the proposed dipole antenna exhibits wide impedance bandwidth (S11&S22 ≤ -12dB) of 52% from 0.675 to 1.15 GHz, covering the lower frequency band (0.69~0.96GHz) of base station antenna. Simulated results show that the front-to-back ratio can be increased by 4-5dB after adding the meta-surface, radiation pattern with enhanced frontto-back ratio (FBR) higher than 20dB were achieved over the operating frequency range. In addition, the antenna architecture is simple and easy to fabricate in base stations that can be used in modern mobile communication systems.

关键词： Dipole antennas Broadband antennas Antenna radiation patterns Probes Broadband communication Bandwidth

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Physical Layer Security of Cooperative Network with Machine Learning-based Relay Selection

Physical Layer Security of Cooperative Network with Machine ...

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IEEE International Symposium on Electromagnetic Compatibility (EMC-Beijing)

作者： Fang Liu Yajuan Wang Hu Li Beijing University of Posts and Telecommunications Beijing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (数字)9781728144160

ISBN: (纸本)9781728144177

We explore the potential of machine learning for relay selection in a cooperative multi-relay wiretap network with decode-and-forward (DF) protocol, aiming to enhance the physical layer security. Such network is divided into two scenarios according to whether the channel state information (CSI) of wiretap links is available or not for source, when it is assumed that the CSI of the main links has been known at the source. In addition, two machine learning-based schemes, namely, the convolutional neural network(CNN)-based multi-classifier and the support vector machine(SVM)-based multi-classifier, are proposed to characterize the conventional optimization problem of cooperative relay selection as a multi-classification problem in two scenarios mentioned above. In our study, we provide more insight into the spatial correlation of CSI and make the first attempt to introduce the CNN for relay selection in a cooperative multi-relay wiretap network. Finally, the simulation results indicate that two machine learning-based with relatively low selection complexity and less feedback amount achieve substantially the same secrecy performance as the conventional selection scheme.

关键词： Relays Training Machine learning Support vector machines Physical layer security Neurons Correlation

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A Novel Deceptive Jamming Method Via Frequency Diverse Array

A Novel Deceptive Jamming Method Via Frequency Diverse Array

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Wei Mao Hui Wang Shunsheng Zhang Xiangrong Liu National Key Laboratory of Science and Technology Test Physics and Numerical Mathematics Beijing China Research Institute of Electronic Science and Technology University of Electronic Science and Technology of China Chengdu China

Different from traditional single-element and phased-array antennas, frequency diverse array (FDA) uses a slight frequency offset across the elements to produce angle-, range- and even time-dependent transmit beampattern, which provides promising potentials to develop new jamming techniques on synthetic aperture radar (SAR) imaging. In this paper, we propose a novel deception jamming method against SAR imaging, which uses FDA to quickly generate false targets. Moreover, the position of the false target is controlled by the jammer, and the number of false targets is determined by the number of FDA elements. The proposed methods are validated by extensive simulation results with range-Doppler imaging algorithm.

关键词： Jamming Synthetic aperture radar Imaging Azimuth Interference Radar imaging

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Impact analysis of CFAR detection for false targets generated by the phase-switched screen

Impact analysis of CFAR detection for false targets generate...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Ran Zhang Yuan S Chen Yu X Zhang Lei Guo Liang J Bai Ping L Zhang National key laboratory of science and technology on test physics and numerical mathematics Beijing institute of Space Long March Vehicle No. 1 Nanda Hongmen Road of Fengtai District Beijing China National key laboratory of science and technology on test physics and numerical mathematics Beijing institute of Space Long March Vehicle Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

The phase-switched screen (PSS) has been proved effective in the application of shielding a target or deceiving the radar system when the modulation frequency of it is set greater or smaller than the signal bandwidth. This paper analyses impacts of false targets generated by PSS (PSS-decoys) echoes on radar constant false alarm rate detection. The generation principle of PSS-decoys and the key factors that influence the signatures of PSS-decoys are introduced briefly at first. On base of it, the detection cost caused by the false alarm and false dismissal in a search period of radar is chosen as the criteria of detection performance. The detection costs of CA-CFAR, OS-CFAR, CMLD-CFAR detectors under multiple decoys jamming environment are analysed. Specially, we investigate the influence of the PSS key factors on detection costs from the perspective of simulation. The results show that detection costs will increase remarkably due to false targets existing and it is sensitive to the switching frequency, and the relationship to the duty ratio is tightly relevant to SNR. Among three detectors, the detection costs of CMLD-CFAR detector are higher than that of adopting CA-CFAR and that of adopting OS-CFAR.

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Harnessing Atomic-Scale Thinning in Two-Dimensional Organic Molecular Crystals for In-Situ Characterization and Superior Optoelectronics

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Nano letters 2025年第23期25卷 2025 May 29页

作者： Linglong Zhang Fan Yang Fuguo Tian Yichun Cui Kan Zhou Tong Tong Haizeng Song Zhixing Gan Han Yan Xueqian Sun ShunShun Yang Rui Fang Jiong Yang Neng Wan Yangyang Fu Hucheng Song Yongbiao Zhai Youwen Liu Yi Shi Yuerui Lu College of Physics Nanjing University of Aeronautics and Astronautics Key Laboratory of Aerospace Information Materials and Physics (NUAA) MIIT Nanjing 211106 China. Laboratory of Solid State Microstructures Nanjing University Nanjing 210093 China. National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing 100076 China. National Key Laboratory on Electromagnetic Environment Effects and Electro-Optical Engineering PLA Army Engineering University Nanjing 210007 China. School of Physical Science and Technology Suzhou University of Science and Technology Suzhou 215009 China. Center for Future Optoelectronic Functional Materials School of Computer and Electronic Information/School of Artificial Intelligence Nanjing Normal University Nanjing 210023 China. Department of Materials Science and Metallurgy University of Cambridge Cambridge CB30FS U.K. School of Engineering College of Engineering and Computer Science the Australian National University Canberra 0200 Australian Capital Territory Australia. School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China Soochow University Suzhou 215006 China. SEU-FEI Nano Pico Center Key Laboratory of MEMS of Ministry of Education School of Electronics Science and Engineering Southeast University Nanjing 210096 China. College of Electronics and Information Engineering Shenzhen University Shenzhen 518060 P. R. China.

Two-dimensional organic single crystals (2D OSCs) offer high crystallinity and quantum limit properties, making them ideal for exploring unique quantum phases and developing scaled optoelectronic devices. However, accurately probing the structure-optoelectronic relationship in 2D OSCs remains challenging. Here we realize in situ optoelectronic characterization of 2D OSCs through an atomically precise thinning technique. Thinning 3D pentacene crystals to the monolayer limit induces a phase transition from Frenkel excitons to charge-transfer (CT) excitons, achieving a near-unity quantum yield (∼95.1%). In-situ electrical measurements demonstrate that this thinning improves carrier mobility and reduces threshold voltages. Utilizing 2D pentacene crystals, we construct a high-performance synapse device, showing a record paired-pulse facilitation index (PPF index ∼ 261%). This remarkable synaptic plasticity further allows us to emulate the human vision system, predicting the object trajectory with exceptional accuracy (∼99.1%). These results provide new insights into the intrinsic properties of 2D OSCs and lay the foundation for multifunctional optoelectronic applications.

关键词： artificial synaptic devices bionic machine vision in situ optoelectronic characterizations large-scale organic crystal monolayer ultrahigh paired-pulse facilitation

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A Physical Layer key Generation method with Reliable Negotiation

A Physical Layer Key Generation method with Reliable Negotia...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Yuchen Wang Xuanli Wu Zhicong Xu Wei Wu Hu Li Ran Zhang School of Electronics and Information Engineering Harbin Institude of Technology Harbin China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

There is a risk of information leakage in the process of wireless communication. The introduction of key generation in the physical layer can effectively improve the security of wireless communication. This paper proposes a new physical layer key generation method in the TDD (time division duplex) communication system. Assume that the uplink and downlink channels are reciprocal. Through LDPC (Low Density Parity Check)channel coding and negotiation algorithm, the inconsistency rate of key generation between Alice and Bob is reduced. Simulation and analysis results show that the method improves the key generation rate and reduces the key inconsistency rate.

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