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Dual-band dynamic reconfigurable intelligent surface for signal enhancement in millimeter wave

Science China(Technological Sciences) 2024年第4期67卷 1133-1138页

作者： YAO HuiMing DU XinRun WANG HengBin GAO Song PANG YaChen ZHENG HaiRong GONG HuiWen LI Yi XU JianChun ZHANG JianHua BI Ke State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

Millimeter wave with large bandwidth,high transmission rate,and low delay is considered a reliable alternative to cope with the spectrum ***,the fast attenuation and narrow beam characteristics make it difficult to achieve long-distance or wide-range ***,a 1-bit dual-band reflective reconfigurable intelligent surface(RIS)for signal enhancement in millimeter wave with 16×16 elements is designed,fabricated,and *** from most existent RIS,dynamic programming is realized at two separate frequency bands by integrating the PIN diodes and field-programmable gate array(FPGA).Particularly,the beam deflection,dual-beam,and multi-beam are created based on the coding theory and convolution operation,proving the effectiveness of wavefront ***,the far-field patterns and signal power with different coding sequences are measured and *** is indicated that the received signal power is 6–7 dB stronger than that without coding,which shows good agreement with the desired *** proposed reconfigurable metasurface exhibits great potential in beam forming,making it a promising candidate for progressive wireless communication applications.

关键词： dual-band millimeter wave reconfigurable intelligent surface signal enhancement

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A Double-Timescale Reinforcement Learning Based Cloud-Edge Collaborative Framework for Decomposable Intelligent Services in Industrial Internet of Things

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China Communications 2024年第10期21卷 181-199页

作者： Zhang Qiuyang Wang Ying Wang Xue School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory of Networking and Switching Technology(Beijing University of Posts and Telecommunications) Beijing 100876China

With the proportion of intelligent services in the industrial internet of things(IIoT)rising rapidly,its data dependency and decomposability increase the difficulty of scheduling computing *** this paper,we propose an intelligent service computing *** the framework,we take the long-term rewards of its important participants,edge service providers,as the optimization goal,which is related to service delay and computing *** the different update frequencies of data deployment and service offloading,double-timescale reinforcement learning is utilized in the *** the small-scale strategy,the frequent concurrency of services and the difference in service time lead to the fuzzy relationship between reward and *** solve the fuzzy reward problem,a reward mapping-based reinforcement learning(RMRL)algorithm is proposed,which enables the agent to learn the relationship between reward and action more *** large time scale strategy adopts the improved Monte Carlo tree search(MCTS)algorithm to improve the learning *** simulation results show that the strategy is superior to popular reinforcement learning algorithms such as double Q-learning(DDQN)and dueling Q-learning(dueling-DQN)in learning speed,and the reward is also increased by 14%.

关键词： computing service edge intelligence industrial internet of things(IIoT) reinforcement learning(RL)

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Edge Intelligence Assisted Resource Management for Satellite Communication

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China Communications 2022年第8期19卷 31-40页

作者： Yaohua Sun Mugen Peng State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

Satellite communication has been seen as a vital part of the sixth generation communication,which greatly extends network *** satellite communication,resource management is a key problem attracting many research ***,previous study mainly focuses on throughput improvement via power allocation and spectrum assignment and the proposed approaches are mostly model-based and dedicated to specific problem ***,with the trend of edge intelligence,complex resource management problems can be efficiently resolved in a model-free *** this paper,a joint beam activation,user-beam association and time resource allocation approach is *** core idea is using stochastic learning at the ground station to identify active user-link beams to meet user rate *** addition,the convergence,optimality and complexity of our proposal are rigorously *** simulation,it is shown that the rate goal of most of the users can be met and meanwhile satellite energy is saved owing to much less active beams.

关键词： satellite communication resource management stochastic learning

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ADC-DL:Communication-Efficient Distributed Learning with Hierarchical Clustering and Adaptive Dataset Condensation

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China Communications 2022年第12期19卷 73-85页

作者： Zhipeng Gao Yan Yang Chen Zhao Zijia Mo State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

The rapid growth of modern mobile devices leads to a large number of distributed data,which is extremely valuable for learning ***,model training by collecting all these original data to a centralized cloud server is not applicable due to data privacy and communication costs concerns,hindering artificial intelligence from empowering mobile ***,these data are not identically and independently distributed(Non-IID)caused by their different context,which will deteriorate the performance of the *** address these issues,we propose a novel Distributed Learning algorithm based on hierarchical clustering and Adaptive Dataset Condensation,named ADC-DL,which learns a shared model by collecting the synthetic samples generated on each *** tackle the heterogeneity of data distribution,we propose an entropy topsis comprehensive tiering model for hierarchical clustering,which distinguishes clients in terms of their data ***,synthetic dummy samples are generated based on the hierarchical structure utilizing adaptive dataset *** procedure of dataset condensation can be adjusted adaptively according to the tier of the *** experiments demonstrate that the performance of our ADC-DL is more outstanding in prediction accuracy and communication costs compared with existing algorithms.

关键词： distributed learning Non-IID data partition hierarchical clustering adaptive dataset condensation

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Federated Reinforcement Learning with Adaptive Training Times for Edge Caching

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China Communications 2022年第8期19卷 57-72页

作者： Shaoshuai Fan Liyun Hu Hui Tian State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

To relieve the backhaul link stress and reduce the content acquisition delay,mobile edge caching has become one of the promising *** this paper,a novel federated reinforcement learning(FRL)method with adaptive training times is proposed for edge *** a new federated learning process with the asynchronous model training process and synchronous global aggregation process,the proposed FRL-based edge caching algorithm mitigates the performance degradation brought by the non-identically and independently distributed(noni.i.d.)characteristics of content popularity among edge *** theoretical bound of the loss function difference is analyzed in the paper,based on which the training times adaption mechanism is proposed to deal with the tradeoff between local training and global aggregation for each edge node in the *** simulations have verified that the proposed FRL-based edge caching method outperforms other baseline methods in terms of the caching benefit,the cache hit ratio and the convergence speed.

关键词： edge caching federated reinforcement learning(FRL) non-identically and independently distributed(non-i.i.d.)

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Single-shot Carrier Phase Positioning Method with Wrapping Effect Solution in 5G New Radio Cellular Networks

Single-shot Carrier Phase Positioning Method with Wrapping E...

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2024 IEEE Global Communications Conference, GLOBECOM 2024

作者： Ou, Jinghang Fan, Shaoshuai Tian, Hui Beijing University of Posts and Telecommunications State Key Laboratory of Networking and Switching Technology Beijing100876 China

ISBN: (纸本)9798350351255

As the demand for positioning accuracy reaches the centimeter level, Carrier Phase Positioning (CPP) technology has received widespread attention in 5G New Radio (NR) positioning scenarios due to its high ranging accuracy. In this paper, we presents a new single-shot CPP method suitable for 5G NR cellular networks. By performing a search in the coordinate neighborhood space of the Time Difference of Arrival (TDOA) positioning results, the proposed method bypasses the need for resolving the integer ambiguity required for CPP. It also includes a wrapping effect detection and elimination for the carrier phase measurements. The proposed method finally get the positioning result by calculating cost function which considers both TDOA and CPP results. Numerical simulations demonstrate superior performance compared to other positioning solutions. © 2024 IEEE.

关键词： 5G mobile communication systems

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Hybrid CRB Analysis for Location Sensing in UAV mmWave Systems Under Jittering Effects 16

Hybrid CRB Analysis for Location Sensing in UAV mmWave Syste...

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16th International Conference on Wireless Communications and Signal Processing, WCSP 2024

作者： Chen, Wenyun Liu, Chenxi Peng, Mugen Beijing University of Posts and Telecommunications State Key Laboratory of Networking and Switching Technology Beijing100876 China

ISBN: (纸本)9798350390643

Unmanned aerial vehicle (UAV) systems are vulnerable to the inevitable UAV jitter, the impacts of which on both communications and sensing become more detrimental in the high frequency millimeter wave (mmWave) band. While the UAV jittering effects on communications have been intensively investigated, those on sensing have so far drawn little attention. In this paper, we investigate the location sensing performance of the UAV mmWave system in the presence of jitter. To this end, we identify that the location sensing performance under jittering effects is determined not only the deterministic target's location, but also random instantaneous attitude angles of the UAV. Based on this identification, we derive the closed-form expression of the hybrid Cramer-Rao bound (HCRB) and its approximation to characterize the location sensing performance of our considered system, revealing how the UAV jitter introduces extra location sensing error. Through numerical results, we validate our HCRB analysis. Moreover, we show that the detrimental effects of UAV jitter can be well alleviated by increasing the number of measurements. © 2024 IEEE.

关键词： Cramer-Rao bounds

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Gaussian Decoupling Based Stochastic Resonance for Weak Optical Signal Detection 24

Gaussian Decoupling Based Stochastic Resonance for Weak Opti...

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24th IEEE International Conference on Communication technology, ICCT 2024

作者： Chen, Zhibei Yuan, Renzhi Wang, Siming Chu, Xinyi Di, Shijie Li, Junwei Li, Yuchai Sun, Kailin Guo, Jia Beijing University of Posts and Telecommunications State Key Laboratory of Networking and Switching Technology Beijing100876 China

ISBN: (纸本)9798350363760

Weak signal detection methods can improve the SNR by recognizing the effective signals submerged in background noise. However, the existing stochastic resonance (SR) method is confined exclusively to the optimization of potential function parameters. Actually, the bit-error rate (BER) can be optimized by eliminating the correlation among SR output points. In this work, we propose a Gaussian decoupling based SR method to improve the detection performance of weak optical signals. We first perform the SR method on the received weak optical signal and approximate the probability distribution of the SR output points as a multi-dimensional Gaussian distribution. Then we apply a linear transformation based on eigenvalue decomposition of the Gaussian covariance matrix to decouple the correlation among SR output points. Numerical results show that the BER of Gaussian decoupling based SR method can be one order of magnitude lower than that of the ordinary SR method even when the SNR of input signal is -8 dB. © 2024 IEEE.

关键词： Eigenvalues and eigenfunctions

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BGP prefix hijack detection algorithm based on MOAS event feature

BGP prefix hijack detection algorithm based on MOAS event fe...

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2024 International Conference on Computer Network Security and Software Engineering, CNSSE 2024

作者： Chen, Kaiyu State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing100876 China

ISBN: (纸本)9781510680234

Border Gateway Protocol (BGP) is the Internet standard inter-domain routing protocol, has become an important infrastructure of the Internet. Due to the limitation of the initial design, BGP prefix hijacking is a kind of BGP security problem that needs to be solved urgently. This paper proposes a BGP prefix hijack detection algorithm based on Multiple Origin AS (MOAS) event feature, discovering and restoring MOAS events from BGP packets, and creating an event matrix for MOAS events based on the changes of source AS observed from different observation points over time. According to the MOAS event matrix, the eigenvalue of the event is calculated from the perspective of the overall probability of the event and the local visibility of the observation point. Finally, the characteristic value of the MOAS event is compared with the exception event threshold to determine whether the event is an exception event, and then the BGP prefix hijacking is found. Compared with the prefix hijacking detection algorithm based on source AS validity, the detection results of this algorithm have higher accuracy. This method is more practical in detecting prefix hijacking according to the characteristics of the event itself. © 2024 SPIE.

关键词： Anomaly detection

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Device-Cloud Collaborative DDoS Resistance for QoS-Sensitive Mobile Applications: A Seamlessly Shuffle-based Moving Target Defense Approach

Device-Cloud Collaborative DDoS Resistance for QoS-Sensitive...

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2024 IEEE Global Communications Conference, GLOBECOM 2024

作者： Yan, Lin Zhou, Zan Yang, Shujie Xu, Changqiao Beijing University of Posts and Telecommunications State Key Laboratory of Networking and Switching Technology Beijing100876 China

ISBN: (纸本)9798350351255

DDoS attacks pose a fundamental security consideration for any application. With the rapid development of technology, highly QoS-sensitive and rich interaction mobile applications have occupied a great portion of current network traffic. However, owing to their inherent compatibility defects, current shuffle-based solutions fail to accommodate the urgent needs of QoS-sensitive applications, as the defenders require either nonnegligible service interruption or obligatory system modification. Therefore, we propose a feasible DDoS defense solution called RINP, which can be seamlessly integrated with existing applications through its innovative overlay-based wrap mechanism and isolated sidecar implementation. What's more, we mathematically analyse the communication efficiency and false positive rate of RINP, which provides theoretical foundation for further adaptive defense strategy generation. Last but not least, to demonstrate the superiority of the RINP demo, we conduct a series of experiments in real-world WAN scenarios. The experimental results with Iperf3 (both TCP/UDP modes) show that our compatible defense solution can jointly provide great service continuity and maintain high-quality QoS. To the best of our knowledge, this is the first user-imperceptible and nonintrusive device-cloud collaborative defense solution for QoS-sensitive mobile applications. The source code can be found at https://***/bupt-narc/rinp. © 2024 IEEE.

关键词： HTTP

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