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Beamforming design for covert broadcast communication with hidden adversary

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Science China(Information Sciences) 2024年第6期67卷 384-398页

作者： Weiyu CHEN Haiyang DING shilian wang Junshan LUO Fengkui GONG College of Electronic Science and Technology National University of Defense Technology College of Information and Communication National University of Defense Technology State Key Laboratory of Integrated Service Networks Xidian University

This paper explores covert broadcast communication in a challenging situation in which the transmitter, Alice, faces uncertainty regarding the position of the passive adversary, Willie. In this situation,controlling the signal exposure becomes difficult. Specifically, this paper focuses on the cases where Alice can delimit the suspicious areas where Willie may be located. The suspicious areas can have arbitrary number and shapes. Under the Rician fading model, the analytical expression of Willie's detection performance is derived. Then, the transmit power, the beamforming direction, and the number of channel uses are jointly designed to minimize the optimal Willie's detection performance among all the possible positions of Willie, on the premise of satisfying receivers' quality-of-service requirements. To tackle the formulated knotty problem with an infinite number of irregular and discontinuous Willie's possible positions, the continuous nature of the antenna pattern is exploited to convert the original problem into the one with a finite number of possible positions, by sampling the suspicious areas. Then, different algorithms are developed to address the resultant non-convex optimization problem for single-antenna Willie and multi-antenna Willie, respectively. Numerical results demonstrate significant performance gains of the proposed scheme over the widely-adopted maximum ratio transmission scheme, which indicates that simply adjusting the main lobe towards the receiver is indeed far away from optimum and shows the importance of leveraging Alice's limited knowledge of Willie's position.

关键词： low-probability-of-detection communication multiple antennas covertness performance uncertain position parameters optimization

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基于CNN-GRU的对流层散射通信短期传输损耗预测

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电讯技术 2024年第8期64卷 1175-1180页

作者：赵玉超钱佳静芮义斌王世练国防科技大学电子科学学院长沙410073 中国电子科技集团公司第五十四研究所石家庄050081 南京理工大学电子工程与光电技术学院南京210094

针对对流层散射通信短期传输损耗预测这一难题,提出了一种基于卷积神经网络联合门控循环单元(Convolutional Neural Networks-Gated Recurrent Neural Network, CNN-GRU)的混合神经网络模型,利用CNN提取气象数据的特征,再利用GRU提取数... 详细信息

针对对流层散射通信短期传输损耗预测这一难题,提出了一种基于卷积神经网络联合门控循环单元(Convolutional Neural Networks-Gated Recurrent Neural Network, CNN-GRU)的混合神经网络模型,利用CNN提取气象数据的特征,再利用GRU提取数据的时间相关性特征,最后通过全连接层将特征映射到信道传输损耗,从而利用气象数据实现对散射通信短期传输损耗的预测。通过实测数据进行了验证,结果显示该模型相对现有的短期预测算法精确度提升10.98%,最大误差下降8.57 dB,能更准确地预测对流层散射通信短期传输损耗。

关键词：散射通信短期传输损耗预测卷积神经网络门控循环单元

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γ能谱级联符合相加效应校正技术研究进展

核技术 2024年第3期47卷 1-9页

作者：樊元庆李奇张新军赵允刚贾怀茂张瑞芹李芮莹牛亚洲王世联禁核试北京国家数据中心和北京放射性核素实验室北京100085

使用γ谱仪近距离测量具有级联衰变关系的放射性核素时会不可避免地发生级联符合相加效应。级联符合相加效应会导致能谱中的全能峰计数变化,并产生干扰能谱分析的加和峰,从而影响γ能谱分析的准确性和效率,为此,国内外研究机构建立了多... 详细信息

使用γ谱仪近距离测量具有级联衰变关系的放射性核素时会不可避免地发生级联符合相加效应。级联符合相加效应会导致能谱中的全能峰计数变化,并产生干扰能谱分析的加和峰,从而影响γ能谱分析的准确性和效率,为此,国内外研究机构建立了多种方法和技术用于γ能谱级联符合相加效应的校正。本文在详细总结级联符合相加效应校正技术发展历程的基础上,对级联符合相加效应的产生机制、校正算法、校正软件、技术应用等进行了综述,并对不同校正算法和软件进行了比较。结合发展现状,对级联符合相加效应校正技术今后的研究方向提出了建议。

关键词：级联符合相加效应 γ能谱加出效应加入效应

MIMO-DCSK communication scheme and its performance analysis over multipath fading channels

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Journal of Systems Engineering and Electronics 2013年第5期24卷 729-733页

作者： shilian wang Shujun Lu Eryang Zhang School of Electrical Science and Engineering National University of Defense Technology

The differential chaotic shift keying （DCSK） communication in multiple input multiple output （MIMO） multipath fading chan- nels is considered. A simple MIMO-DCSK communication scheme based on orthogonal multi-codes （OMCs） and equal gain combination （EGC） is proposed, in which OMCs are used to spread the same information bit at each transmitting antenna and the infor- mation bit is detected by EGC at receiving antenna. The OMCs are constructed from one chaotic sequence by means of othogo- nal space-time block coding （OSTBC）. The output signal-to-noise ratio （SNR） after EGC is given based on central limit theory （CLT）, and it can effectively exploit the spatial diversity of the underlying MIMO system. Simulation results show that the full spatial diversity gain is achieved without channel estimation in the MIMO-DCSK communication scheme and it performs better than MC-EGC for a large number of transmitting antennas.

关键词： chaotic communication differential chaotic shift keying (DCSK) multiple input multiple output (MIMO) orthogonal multi- code (OMC) equal gain combination (EGC).

Inter-satellite Radio Links and Spread-spectrum Ranging for Satellite Formation Flying

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Inter-satellite Radio Links and Spread-spectrum Ranging for ...

Ambient Backscatter Communications over NOMA Downlink Channels

2002 3rd International Conference on Microwave and Millimeter Wave Technology

作者： wang.shilian Zhang.eryang School of Electronic Science and Engineering National University of Defence Technology

ISBN: (纸本)078037486X

＜正＞To maintain and control a satellite cluster effectively,an on-board executive controller is necessary. Both information exchange among satellites and relative position determination with high accuracy in real time are of prime importance in satellites formation flying. This article firstly makes an overview of research programs of formation flying satellites cluster with inter-satellite link（ISL） at *** proposals for the development of ISL low layer protocols are presented in the following.A novel satellite-to-satellite ranging model based on direct spread spectrum in inter-satellite radio links are brought forward,the corresponding expected system performance of ranging accuracy is analyzed theoretically in the end.

关键词： satellite links space communication links transport protocols spread spectrum communication distance measurement channel coding radiofrequency interference inter-satellite radio link intersatellite links satellite-to-satellite ranging model spread-spectrum ranging satellite formation flying formation flying satellite cluster satellite constellations on-board executive controller multi-path interference satellite cluster control low layer protocols distance measurement on-board guidance/navigation/control RFI

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China Communications 2020年第6期17卷 80-100页

作者： Weiyu Chen Haiyang Ding shilian wang Daniel Benevides daCosta Fengkui Gong Pedro Henrique Juliano Nardelli College of Electronic Science and Technology National University of Defense TechnologyChangsha 410073China College of Information and Communication National University of Defense TechnologyXi’an 710106China Department of Computer Engineering Federal University of CearáSobral 62010-560Brazil State Key Laboratory of Integrated Service Networks Xidian UniversityXi’an 710071China School of Energy Systems Lappeenranta University of TechnologyLappeenranta 53850Finland

In this paper,we investigate the performance of commensal ambient backscatter communications(AmBC)that ride on a non-ortho go nal multiple access(NOMA)downlink transmission,in which a backscatter device(BD)splits part of its received signals from the base station(BS)for energy harvesting,and backscatters the remaining received signals to transmit information to a cellular ***,under the power consumption constraint at BD and the peak transmit power constraint at BS,we derive the optimal reflection coefficient at BD,the optimal total transmit power at BS,and the optimal power allocation at BS for each transmission block to maximize the ergodic capacity of the ambient backscatter transmission on the premise of preserving the outage performance of the NOMA downlink ***,we consider a scenario where the BS is restricted by a maximum allowed average transmit power and the reflection coefficient at BD is fixed due to BD’s low-complexity *** algorithm is developed to determine the optimal total transmit power and power allocation at BS for this ***,a low-complexity algorithm is proposed for this scenario to reduce the computational complexity and the signaling ***,the performance of the derived solutions are studied and compared via numerical simulations.

关键词： power-domain NOMA ambient backscatter communications IoT wireless-powered devices optimization

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热加工方式对火麻仁风味与品质的影响

中国食品学报 2022年第2期22卷 200-212页

作者：赖惠敏王世连阮征李汴生华南理工大学食品科学与工程学院广州510640

采用常压蒸制、炒制、热风烘烤以及微波4种热加工方式处理云南大姚火麻仁。以火麻仁香味为指标,探究4种热加工方式在最佳香味处理条件下对其挥发性风味物质、色泽、营养成分及贮藏稳定性的影响。结果表明:4种热加工方式最优处理条件分别... 详细信息

采用常压蒸制、炒制、热风烘烤以及微波4种热加工方式处理云南大姚火麻仁。以火麻仁香味为指标,探究4种热加工方式在最佳香味处理条件下对其挥发性风味物质、色泽、营养成分及贮藏稳定性的影响。结果表明:4种热加工方式最优处理条件分别为100℃常压蒸制8 min、150℃炒制15 min、130℃热风烘烤40 min以及600 W功率微波4 min。未处理火麻仁中含有较多的2-3丁二醇(10.21%)、1-己醇(7.92%)等醇类物质。4种热加工方式均可使挥发性风味物质的种类和含量增加,其中炒制处理和热风烘烤可明显增加醛类、杂环类物质的含量。不同热加工方式处理后火麻仁的色泽、蛋白质、总糖、灰分、脂肪、总酚、总黄酮含量及不饱和脂肪酸比例存在显著性差异(P<0.05)。微波处理可保留较高含量的蛋白质、总酚和总黄酮;蒸制处理和热风烘烤后可保留较高比例的不饱和脂肪酸,其中亚麻酸保留率最高,分别为92.64%和98.73%。不同热加工方式处理的火麻仁对脂肪氧化酶均有显著的抑制作用(P<0.05),在短期贮藏过程中均能抑制脂肪的氧化。本研究结果为火麻仁深层次的加工利用提供参考。

关键词：火麻仁热加工方式挥发性风味物质脂肪酸相对含量脂肪氧化酶

Seawater Short-Range Electromagnetic Wave Communication Method Based on OFDM Subcarrier Allocation

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Journal of Computer and Communications 2019年第10期7卷 63-71页

作者： Jun wang shilian wang College of Electronic Science and Technology National University of Defense Technology Changsha China

Aiming at the problems of underwater acoustic communication such as narrowband, low speed and multipath effect, this paper studies the high-speed communication technology of electromagnetic wave in short distance at sea. The channel model of seawater electromagnetic wave is given, and the performance of different modulation modes in this channel is analyzed. A meth-od of seawater short-range high-speed electromagnetic wave communication based on OFDM is proposed. In order to reduce the BER of the system, a method of allocating different modulation modes to subcarriers in seawater channel is introduced, which combines frequency domain equalization. This method has low complexity, improves the utilization of frequency band, and improves the reliability. It can realize high-speed and reliable communication in short distance in seawater.

关键词： Underwater Electromagnetic Wave OFDM Subcarrier Modulation

非对称Colonel Blotto博弈模型下的多信道功率分配抗干扰

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国防科技大学学报 2023年第1期45卷 35-48页

作者：魏鹏王世练陆锐敏骆俊杉国防科技大学第六十三研究所江苏南京210007 国防科技大学电子科学学院湖南长沙410073

针对智能干扰条件下传输速率固定的通信系统多信道功率分配问题,建立了非对称Colonel Blotto博弈模型。在完全信息条件下,推导出了各种功率预算约束下通信方和干扰方的等效单信道最优功率分配策略,进而证明了通信方和干扰方存在唯一混... 详细信息

针对智能干扰条件下传输速率固定的通信系统多信道功率分配问题,建立了非对称Colonel Blotto博弈模型。在完全信息条件下,推导出了各种功率预算约束下通信方和干扰方的等效单信道最优功率分配策略,进而证明了通信方和干扰方存在唯一混合纳什均衡策略,并求得了纳什均衡收益。基于等效单信道最优功率分布,提出了一种多重扫描直接列元素交换算法,可以快速构建多信道混合功率分配矩阵,且相比于线性规划方法,可适应更多的信道数和更广的功率分布范围。通过数值仿真,验证了所提多信道混合功率分配矩阵构造算法的有效性及多信道功率分配策略的最优性。

关键词：非对称Colonel Blotto博弈抗干扰多信道功率分配混合策略纳什均衡