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IEEE International Conference on Information communication and Signal Processing (ICICSP)

作者： Chao Yang Yi Yang Defeng Liu Nai Lin Wei Liu Jie Zhuang Beijing Changcheng Aeronautic Measurement and Control Technology Research Institute China School of Information and Communication Engineering University of Electronic Science and Technology of China (UESTC) Chengdu China The 10th Research Institute of CETC Chengdu Sichuan China

The terahertz radar system can realize accurate detection, high-resolution imaging, and feature recognition of targets due to its small size, lightweight, and high resolution. Based on this special-shaped terahertz frequency-modulated continuous-wave radar, this paper studies the slope control of the transmitter and the local oscillator signal source and the change rule of the difference frequency signal and the effective acquisition interval. A short-time Fourier transform is used to simulate and verify the effective acquisition interval of the received intermediate frequency signal. It can be seen from the experimental results that under the special-shaped structure, controlling the FM continuous-wave slope at the transmitting and receiving ends can obtain the desired frequency-varying frequency signal, which can verify the correctness of the theoretical derivation.

关键词： Time-frequency analysis Terahertz wave imaging Frequency modulation Fourier transforms Transmitters Target recognition Radar

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Performance analysis of intelligent reflecting surface assisted NOMA networks

arXiv

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arXiv 2020年

作者： Yue, Xinwei Liu, Yuanwei Key Laboratory of Modern Measurement and Control Technology Ministry of Education School of Information and Communication Engineering Beijing Information Science and Technology University Beijing100101 China School of Electronic Engineering and Computer Science Queen Mary University of London LondonE1 4NS United Kingdom

Intelligent reflecting surface (IRS) is a promising technology to enhance the coverage and performance of wireless networks. We consider the application of IRS to non-orthogonal multiple access (NOMA), where a base station transmits superposed signals to multiple users by the virtue of an IRS. The performance of an IRS-assisted NOMA networks with imperfect successive interference cancellation (ipSIC) and perfect successive interference cancellation (pSIC) is investigated by invoking 1-bit coding scheme. In particular, we derive new exact and asymptotic expressions for both outage probability and ergodic rate of the mth user with ipSIC/pSIC. Based on analytical results, the diversity order of the m-th user with pSIC is in connection with the number of reflecting elements and channel ordering. The high signal-to-noise radio (SNR) slope of ergodic rate for the m-th user is obtained. The throughput and energy efficiency of nonorthogonal users for IRS-NOMA are discussed both in delaylimited and delay-tolerant transmission modes. Additionally, we derive new exact expressions of outage probability and ergodic rate for IRS-assisted orthogonal multiple access (IRS-OMA). Numerical results are presented to substantiate our analyses and demonstrate that: i) The outage behaviors of IRS-NOMA are superior to that of IRS-OMA and relaying schemes;ii) With increasing the number of reflecting elements, IRS-NOMA is capable of achieving enhanced outage performance;and iii) The M-th user has a larger ergodic rate compared to IRS-OMA and benchmarks. However, the ergodic performance of the m-th user exceeds relaying schemes in the low SNR regime. Copyright © 2020, The Authors. All rights reserved.

关键词： Signal to noise ratio

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Adaptive Load Balancing Routing Algorithm for Low Earth Orbit Satellite Cluster Networks

Adaptive Load Balancing Routing Algorithm for Low Earth Orbi...

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International Conference on Computers, communications, and Systems (ICCCS)

作者： Liming Wang Zhan Xu Ruxin Zhi Jiahui Wang School of Electronics and Communication Engineering Beijing Information Science and Technology University Key Laboratory of Information and Communication Systems Ministry of Information Industry Beijing Information Science and Technology University Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science and Technology University Beijing China

ISBN: (数字)9798350350210

ISBN: (纸本)9798350350227

Large-scale satellite networks are a crucial component of future communication systems. However, they pose several challenges to satellite routing design and link recovery. This paper proposes an Adaptive Load Balancing routing algorithm for Low Earth Orbit (LEO) Satellite Cluster Networks (ALBSCN) to meet the needs of large-scale Low Earth Orbit LEO satellite networks. The constellation is divided into clusters, with each cluster maintaining the intra-cluster link state by electing a cluster head. The cluster head computes intra-cluster and inter-cluster routes. Messages are forwarded using inter-cluster multipath routing and intra-cluster routing techniques. We validated the algorithm's performance and compared it with other algorithms in terms of packet delivery delay using simulation. Simulation results indicate that the proposed clustering routing scheme effectively reduced packet loss and end-to-end delay, while also increasing network throughput.

关键词： Satellites Adaptive systems Simulation Clustering algorithms Low earth orbit satellites Packet loss Routing

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Real-Time Routing Design for LEO Satellite Networks: An Enhanced Multi-Agent DRL Approach

Real-Time Routing Design for LEO Satellite Networks: An Enha...

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IEEE International Conference on communications in China Workshops (ICCC)

作者： Hailong Liao Xian Zhang Jiaen Zhou Xuehua Li Key Laboratory of Information and Communication Systems Ministry of Information Industry and the Key Laboratory of Modern Measurement & Control Technology School of Information and Communication Engineering Beijing Information Science and Technology University Beijing China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9798350377675

ISBN: (纸本)9798350377682

Low Earth Orbit (LEO) satellite networks have been heralded as a promising solution for provisioning space-based Internet services. However, the inherent dynamic topology, characterized by frequent variations in inter-satellite link states, causes pronounced fluctuations in latency and exacerbated packet loss rates. To address the challenge, in this paper, we formulate a routing design and optimization problem to maximize the average throughput with considering the end-to-end latency constraint and the real-time routing demand in LEO satellite networks. To solve this problem, we design an enhanced Multi-Agent Deep Reinforcement Learning (MADRL) algorithm, which encapsulates the intricate interplay among LEO satellite agents and their environs within a Real-Time Markov Decision Process (RTMDP) framework, and introduces the self-attention mech-anism to endow agents with a better grasp of environmental state dynamics. Simulation results demonstrate that our proposed routing design outperforms the benchmark schemes in terms of both end-to-end latency and network average throughput.

关键词： Satellites Network topology Simulation Heuristic algorithms Low earth orbit satellites Routing Throughput Real-time systems Topology Optimization

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Strip Weld Inspection Based on Improved VGG16

Strip Weld Inspection Based on Improved VGG16

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IEEE International Conference on Signal and Image Processing (ICSIP)

作者： Sisi Fu Yuan Chen Dexin Xian Shiyuan Kong Hao Wang Jinsong Wang School of Optoelectronic Engineering Changchun University of Science and Technology Zhongshan Guangdong China School of Measurement and Control Technology and Communication Engineering Harbin University of Science and Technology Harbin Heilongjiang China School of Optoelectronic Engineering Zhongshan Institute of Changchun University of Science and Technology Zhongshan Guangdong China School of Optoelectronic Engineering Changchun University of Science and Technology Zhongshan Institute of Changchun University of Science and Technology Zhongshan Guangdong China

As one of the indispensable materials in modern industry, high precision and high efficiency defect detection of strip weld has become an important part of production and quality control. In response to the shortcomings of the existing strip weld detection technology with low detection accuracy, this paper proposes a deep learning based strip weld defect detection and classification technique. First, the CBAM attention mechanism is introduced into the network structure to improve the attention to important features; second, the traditional convolution layer is replaced by using the dilated convolution to reduce the computation while increasing the perceptual field; finally, the original ReLU activation function is replaced by the PReLU activation function to effectively overcome the problem of neuron death in the Relu activation function. The improved model finally achieves a recognition rate of 98.1% in the test set, which is 22.1% higher than that of the unimproved model, greatly improving the accuracy and robustness of the algorithm.

关键词：

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Reliability Study of Leo Satellite Networks Based on Random Linear Network Coding

Reliability Study of Leo Satellite Networks Based on Random ...

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Acoustics, Speech, and Signal Processing Workshops (ICASSPW), IEEE International Conference on

作者： Jiahui Wang Zan Xu Ruxin Zhi Liming Wang School of Electronics and Communication Engineering Beijing Information Science and Technology University China Key Laboratory of Information and Communication Systems Ministry of Information Industry Beijing Information Science and Technology University China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science and Technology University China

ISBN: (数字)9798350374513

ISBN: (纸本)9798350374520

This paper proposes a random linear network coding method tailored for data transmission within Low Earth Orbit (LEO) constellation networks to address the challenges of long delay and high bit error rates (BER) in LEO satellite networks. The method employs a link quality-aware strategy, enabling dynamic adjustment of source-side redundancy based on the corresponding link quality to maximize network fault tolerance with minimal overhead. Validation using the OMNET++ discrete event simulation platform indicates that the proposed method performs well in LEO satellite networks of various scales and configurations, exhibiting superior performance in more extensive networks. In particular, in the 300-LEO and 200-LEO scenarios, the proposed method demonstrates a successful delivery rate improvement of 19.6% and 18.73%, respectively, compared to traditional single-path approaches. This method is deemed more suitable for application in dynamic satellite networks with large hop counts.

关键词： Satellite constellations Satellites Bit error rate Fault tolerant systems Low earth orbit satellites Termination of employment Network coding

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Temperature Response Analysis of Intelligent OPPC Cable Core Based on Finite Element Simulation

Temperature Response Analysis of Intelligent OPPC Cable Core...

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International Conference on Optical communications and Networks (ICOCN)

作者： Wenping Xie Ming Nie Yongchun Liang Xiaoyu Luo Yu Han Hongwei Li Xiaohui Tang Electric Power Research Institute of Guangdong Power Grid Co. Ltd. Guangzhou China Harbin University of Science and Technology Harbin China Heilongjiang Provincial Key Laboratory of Quantum Control School of Measurement and Communication Engineering Harbin China

ISBN: (数字)9798350367652

ISBN: (纸本)9798350367669

The Optical Fiber Composite Overhead Conductor (OPPC) cable is a special type of power optical cable that combines overhead conductor and communication capabilities. It has advantages such as strong wind resistance, good corrosion resistance, high bandwidth transmission, low loss transmission, and high reliability. However, as the OPPC cable operates for a long time power transmission, its long-term working temperature has a significant impact on transmission performance and lifespan. Therefore, monitoring the temperature of the OPPC cable and internal fibers can improve the transmission capacity of the line, ensure good thermal stability, and provide important references for fault warning and maintenance. This study aims to explore the temperature characteristics of the OPPC cable through actual monitoring and analysis, providing guidance and decision-making basis for practical applications.

关键词： Temperature sensors Temperature measurement Resistance Optical fibers Temperature Optical fiber cables communication cables

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Secure communications in a unified non-orthogonal multiple access framework

arXiv

引用

arXiv 2019年

作者： Yue, Xinwei Liu, Yuanwei Yao, Yuanyuan Li, Xuehua Liu, Rongke Nallanathan, Arumugam School of Information and Communication Engineering Key Laboratory of Modern Measurement & Control Technology Ministry of Education Beijing Information Science and Technology University Beijing100101 China School of Electronic Engineering and Computer Science Queen Mary University of London LondonE1 4NS United Kingdom School of Electronic and Information Engineering Beihang University Beijing100191 China

This paper investigates the impact of physical layer secrecy on the performance of a unified non-orthogonal multiple access (NOMA) framework, where both external and internal eavesdropping scenarios are examined. The spatial locations of legitimate users (LUs) and eavesdroppers are modeled by invoking stochastic geometry. To characterize the security performance, new exact and asymptotic expressions of secrecy outage probability (SOP) are derived for both code-domain NOMA (CD-NOMA) and power-domain NOMA (PD-NOMA), in which imperfect successive interference cancellation (ipSIC) and perfect SIC (pSIC) are taken into account. For the external eavesdropping scenario, the secrecy diversity orders by a pair of LUs (the n-th user and m-th user) for CD/PD-NOMA are obtained. Analytical results make known that the diversity orders of the n-th user with ipSIC/pSIC for CD-NOMA and PD-NOMA are equal to zero/ K and zero/one, respectively. The diversity orders of the m-th user are equal to K/one for CD/PD-NOMA. For the internal eavesdropping scenario, we examine the analysis of secrecy diversity order and observe that the m-th user to wiretap the n-th user with ipSIC/pSIC for CD-NOMA and PDNOMA provide the diversity orders of zero/K and zero/one, respectively, which is consistent with external eavesdropping scenario. Numerical results are present to confirm the accuracy of the analytical results developed and show that: i) The secrecy outage behavior of the n-th user is superior to that of the m-th user;ii) By increasing the number of subcarriers, CD-NOMA is capable of achieving a larger secrecy diversity gain compared to PD-NOMA. Copyright © 2019, The Authors. All rights reserved.

关键词： Geometry

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Event-triggered State Estimation for Dynamics Networks with Stochastic Coupling under Uncertain Occurrence Probabilities

Event-triggered State Estimation for Dynamics Networks with ...

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第37届中国控制会议

作者： Hongxu Zhang Jun Hu Lei Zou Department of Applied Mathematics Harbin University of Science and Technology School of Measurement and Communication Harbin University of Science and Technology The Higher Educational Key Laboratory for Measuring & Control Technology and Instrumentations of Heilongjiang Province Harbin University of Science and Technology School of Engineering University of South Wales College of Electrical Engineering and Automation Shandong University of Science and Technology

In this paper, we address the event-triggered state estimation problem for a class of time-varying complex networks subject to multiplicative noises and stochastic coupling under uncertain occurrence probability. The stochastic coupling is modeled by introducing a set of Bernoulli distributed random variables, where the uncertainties of the occurrence probability is characterized. Moreover, the event-triggered mechanism is employed with hope to reduce the network burden and save energy consumption. The aim of the paper is to design the robust state estimator for addressed dynamics networks and derive an optimized upper bound of the estimation error covariance by properly choosing the estimator gain. Finally, simulations and comparisons are provided to verify the validity of the proposed robust state estimation method.

关键词： Stochastic coupling networks State estimation Event-triggered mechanism Multiplicative noises Uncertain occurrence probability

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Prediction-based Optimal Distributed Filtering with communication Delay over Sensor Networks

Prediction-based Optimal Distributed Filtering with Communic...

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第三十八届中国控制会议

作者： Jun Hu Guo-Ping Liu Zidong Wang Hongxu Zhang School of Engineering University of South Wales Heilongjiang Provincial Key Laboratory of Optimization Control and Intelligent Analysis for Complex Systems Harbin University of Science and Technology CTGT center Harbin Institute of Technology Department of Computer Science Brunel University London School of Measurement and Communication Harbin University of Science and Technology

In this paper, the prediction-based distributed filtering problem is discussed for a class of time-varying stochastic systems with communication delay and different types of noises over sensor networks. The communication delay is characterized when the state estimations are transmitted between adjacent sensor nodes. In order to compensate the effects induced by the communication delay, the prediction-based idea is employed and then the active compensation estimation is provided when designing the time-varying distributed filter. In particular, both the prediction-based state estimation and its own innovation measurements are utilized in terms of the concerned sensor networks under given topological structure. Subsequently, a locally minimum upper bound of the filtering error covariance is given by determining the filter gain at each time step. Finally, the validity and advantages of the presented prediction-based distributed filtering method are illustrated by some simulations.

关键词： Time-varying stochastic systems Sensor networks Optimal distributed filtering communication delay Prediction compensation

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