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2019 IEEE International Conference on Signal, Information and Data Processing, ICSIDP 2019

作者： Zheng, Ran Chen, Yuan S Zhang, Yu X Guo, Lei Bai, Liang J Zhang, Ping L Zhang, Ran National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China 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

ISBN: (纸本)9781728123455

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. © 2019 IEEE.

关键词： Signal detection

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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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2019 IEEE International Conference on Signal, Information and Data Processing, ICSIDP 2019

作者： Qi, Sun-Rui Yuan, Chen-Shun Liang, Bai-Jin 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 Beijing100076 China

ISBN: (纸本)9781728123455

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. © 2019 IEEE.

关键词： Time difference of arrival

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Design of Non-uniform Flexible Meta-surface for Antenna Beam-steering

Design of Non-uniform Flexible Meta-surface for Antenna Beam...

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IEEE International Conference on Electronic Information and Communication technology (ICEICT)

作者： Yuwei Qiu Zhiye Jiang Pei Zheng School of Electronic Information Northwestern Polytechnical University Xi'an China National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing China

ISBN: (数字)9781728190457

ISBN: (纸本)9781728190464

Design of non-uniform flexible meta-surface for antenna beam-steering is presented in this paper. By properly tuning the dimensions of quasi-I-shaped unit cells on meta-surface, we propose a bi-layer meta-surface that can achieve beam deflection of up to 34°. Horn antenna is adopted as the feed antenna to illuminate the meta-surface which is printed on flexible plastic sheet. The meta-surface is fixed on the outside surface of horn antenna with an electric motor, making it possible to slide relative to the aperture of feed antenna. The horn antenna together with the meta-surface will work like a projector when operating, the main-beam of the horn antenna can be steered when different frames of the meta-surface cover the horn aperture and the steering range is ±34°. Radiation reconfigurable is thus achieved through a simple structure. Prototype will be fabricated in the following research.

关键词： Horn antennas Prototypes Antenna feeds Aperture antennas Information and communication technology Plastics Tuning

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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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2019 IEEE International Conference on Signal, Information and Data Processing, ICSIDP 2019

作者： Wang, Yuchen Wu, Xuanli Xu, Zhicong Wu, Wei Li, Hu Zhang, Ran 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: (纸本)9781728123455

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. © 2019 IEEE.

关键词： Hash functions

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Low-overlap square aperture ptychography with selective scanning

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Optics and Laser technology 2025年 190卷

作者： Qiao, Ziling Wen, Xiu Chen, Hang Huang, Guancheng Zhou, Xuyang Li, Ziyang Ji, Yu Liu, Wei Chi, Dazhao Gao, Bin Liu, Shutian Xue, Feng Liu, Zhengjun Li, Yutong School of Physics Harbin Institute of Technology Harbin150001 China School of Physical Science and Technology Tiangong University Tianjin300387 China School of Space Information Space Engineering University Beijing101416 China Optical Imaging Laboratory Harbin Institute of Technology Shenzhen518055 China National Key Laboratory of Precision Welding & Joining of Materials and Structures Harbin Institute of Technology Harbin150001 China College of Data Science and Technology Heilongjiang University Harbin150080 China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beiiing100076 China

As an excellent representative of coherent diffraction imaging, ptychography iterative engine plays a crucial role in biomedical imaging and crystal structure analysis. However, the significant challenges regarding imaging speed and throughput have hindered its development in fast imaging. In this paper, we propose a fast square aperture reconstruction method with a low-overlap rate aimed at mitigating the issue of low efficiency. Our approach, employing the Tamura coefficient of gradient (TOG) operator-guided strategy with square aperture, surpasses the performance of previous initial iterations. Enhanced imaging quality is demonstrated by intentionally selecting patterns in the reconstruction stage. Our results illustrate that a high-overlap rate and extensive patterns are no longer indispensable for lensless ptychography. © 2025 Elsevier Ltd

关键词： Computational Imaging

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Application of improved genetic ant colony optimization in radar resource interference allocation

Application of improved genetic ant colony optimization in r...

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IET International Radar Conference (IET IRC 2020)

作者： Y. Liao W. Guo L. Hu Harbin Engineering University Information and Communication Engineering Department Harbin China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

Under the condition of limited interference resources, how to maximize the benefits of multiple jammers interfering with multiple radars has become a research hotspot. This paper has designed a reasonable interference evaluation method. Aiming at the disadvantages of genetic algorithm and ant colony optimization, made some improvements, and combined genetic methods and ant colony optimization, besides, a new crossover and mutation method based on constraints is proposed, which overcomes the shortcomings of invalid iteration of genetic algorithm and easy to fall into local optimal solution of ant colony optimization. Through simulation analysis, the fused algorithm can reach the optimal value within a short number of iterations, improving the utilization efficiency of the jammer.

关键词：

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Mechanically Beam-steering of Horn Antenna Using Non-uniform Flexible Meta-Surface

Mechanically Beam-steering of Horn Antenna Using Non-uniform...

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International Conference on Computer and Communications (ICCC)

作者： Zhiye Jiang Pei Zheng Yuwei Qiu Hailiang Zhu Chenyu Ding Gao Wei National Key Laboratory of Science and Technology on Test Physics &Numerical Mathematics Beijing China School of Electronics and Information Northwestern Polytechnical University Xi'an Shaanxi China

ISBN: (数字)9781728186351

ISBN: (纸本)9781728186368

Research on mechanically beam-steering of horn antenna using non-uniform meta-surface is presented in this paper. After optimizing the layout of quasi-I-shaped unit cell, we designed a flexible bi-layer meta-surface that can bring a main beam deflection of 40°. When the meta-surface is sliding along the long side of horn antenna, the main beam can be steered accordingly in a range of ±40°. A mechanically radiation reconfigurable antenna is thus achieved by a simple structure. Sliding of the meta-surface relative to the horn can be realized by a motor-driven conveyor belt when the prototype is fabricated in the following research.

关键词： Geometry Beam steering Horn antennas Conferences Layout Prototypes Bandwidth

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Unified OSTBC-based communication scheme for cooperative space vehicles

Unified OSTBC-based communication scheme for cooperative spa...

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IET International Radar Conference 2018, IRC 2018

作者： Geng, Jian Liu, Hongyan Jin, Wen Yan, Xinfeng Xu, Jin Beijing Institute of Space Long March Vehicle Beijing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics China

In many spatial cooperative vehicle networks, omni-directional communication is preferred due to its flexibility for networking. In the recent studies, space time code was shown to be an effective approach for improving the performance of the omni-directional communication between space vehicles. This paper studies the unified scheme for the orthogonal space time block code-based transmission between two space vehicles equipped with different numbers of antennas. It is obtained that at most six passive antennas and four RF chains are enough for the typical use. In the proposed scheme, the receiver can perform a unified detection procedure regardless of the actual number of the transmit antennas, which facilitates the practical application. Simulation results validate the proposed scheme in terms of the cumulative distribution function of the received signal-to-noise ratios. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Space time codes

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Deep representation method for radar emitter signal using wavelet packets decomposition

Deep representation method for radar emitter signal using wa...

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IET International Radar Conference 2018, IRC 2018

作者： Cao, Yang Bai, Jin Liang Li, Hongbo Zhao, Jian Liu, Shuo Gao, Zhiyong National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China School of Electronics and Information Engineering Harbin Institute of Technology Harbin China

Signal representation is to transform the intercepted original signal into feature parameters, which is the basis for the electronic reconnaissance system to analyse and identify a radar. The traditional method is to manually design a limited number of features with prior knowledge, which can only achieve the desired results in specific applications. Therefore, it is necessary to study signal representation methods that are more adaptable, reasonable, and effective. This study proposes a feature-level design scheme that extracts multi-level signal feature parameters to obtain deep essential feature representations, which is consistent with deep-learning frameworks. Through the decomposition through wavelet packet transform (WPT), the best sub-band tree structure of the signal can be obtained, and the depth representation of the signal can be well achieved, which can meet requirements of time-frequency analysis automatically. Here, Symlets wavelet packet decomposition (WPD) is used as an example to implement multi-layer signal feature representation. The combination of characteristic parameters at different levels can reflect the different information contained in different radar signals. The simulation results show that the method can effectively identify the modulation mode of radar signals and enhance the information mining ability from radar signals. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Radar

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Station Layout Optimization Genetic Algorithm for Four Stations TDOA Location

Station Layout Optimization Genetic Algorithm for Four Stati...

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第二届人工智能、网络与信息技术国际研讨会

作者： Ruiqi Sun Zhonghang He Lu Gao Jinliang Bai National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics

Station layout has a direct impact on localization precision for four-station TDOA(time difference of arrival) location system. In order to optimize the overall location precision of targets in certain area, genetic algorithm for station layout optimization is presented. GDOP is regarded as the measurement rule of location precision. Then the multi-object programming mathematical model of station layout optimization is built. The optimal solution is searched by genetic algorithm. Consequently, the optimal layout of station is obtained. The simulation provides the GDOP distribution of two station layouts. One is the initial station layout, and the other is the optimal station layout. The simulation results show that for the optimal station layout, the effect of improving the location precision is obvious, and also indicate the validity of genetic algorithm.

关键词： Station Layout Optimization Genetic Algorithm for Four Stations TDOA Location

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