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9th International Conference on Computer and Communications, ICCC 2023

作者： Feng, Tao Nie, Gaofeng Tian, Hui Zhang, Bo Zhao, Yaozhong Beijing University of Posts and Telecommunications State Key Lab. of Networking and Switching Technology Beijing China China Huaneng Yimin Open Coal Mine Hulunbuir China

ISBN: (纸本)9798350317251

Low Earth Orbit (LEO) satellite networks play a crucial role in achieving the ubiquitous connectivity. Due to the limited radio resources and large moving coverage area, the access procedure of LEO networks exhibit a dynamic nature. Traditional access class barring (ACB) scheme adopted in terrestrial networks is able to deal with the access conflicts of massive terminals, but is not suitable for LEO networks with fluctuated serving terminals. To this end, a dynamic access control based on reinforcement learning (DACRL) is proposed in this paper to improve the access adaptation of LEO networks. DACRL iteratively conducts the access terminal quantity adjustment and access conflict control. To achieve a fine access terminal quantity adjustment, a deep Q-network (DQN) with state windows is designed to generate the proper access parameters without knowing the number of access users. To relieve the conflict access, reward of the proposed DQN is formulated by obtaining the tradeoff between the access success rate and the average access delay. Simulation results show that, compared with the reference algorithms, DACRL significantly improves access efficiency and is able to satisfy the access requirements of dynamic terminal quantity. © 2023 IEEE.

关键词： Reinforcement learning

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A Sequential-Fairness RIS Deployment for Indoor Multi-User Systems

A Sequential-Fairness RIS Deployment for Indoor Multi-User S...

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2023 IEEE/CIC International Conference on Communications in China, ICCC 2023

作者： Chang, Qirui Nie, Gaofeng Tian, Hui Li, GuoPeng Zhang, Bo Beijing University of Posts and Telecommunications State Key Lab. of Networking and Switching Technology Beijing China China Huaneng Yimin Open Coal Mine Hulunbuir China

ISBN: (纸本)9798350345384

In this paper, we investigate multi-user systems in indoor environments with priority zones, which are assisted by reconfigurable intelligent surfaces (RIS). Different areas in the scene are assigned different priority levels, with higher priority areas having a higher signal-to-noise ratio (SNR). Our objective is to optimize the deployment position and reflection coefficient of RIS on the ceiling to maximize the minimum SNR among all users. Meanwhile, according to the priority level of users, the relative order of signal-to-noise ratio between users need to be kept unchanged to achieve sequential-fairness. For the deployment position of RIS, we employ a particle swarm optimization (PSO) algorithm. In order to avoid local optima when determining the optimal reflection coefficient of RIS, we use an iterative algorithm consisting of manifold optimization and simulated annealing (SA). The simulation results demonstrate that the proposed algorithm has a fast convergence rate and effectively enhances the SNR of users in the lowest priority area. © 2023 IEEE.

关键词： Signal to noise ratio

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Doppler Analysis and Modeling of V2V Channel at 6 GHz in Typical Urban Scenarios

Doppler Analysis and Modeling of V2V Channel at 6 GHz in Typ...

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European Conference on Antennas and Propagation, EuCAP

作者： Yufeng Qin Pan Tang Lei Tian Peijie Liu Weirang Zuo Qi Wei Jianhua Zhang State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9788831299107

ISBN: (纸本)9798350366327

This paper conducts a measurement campaign for the vehicle-to-vehicle (V2V) channel at 6 GHz in urban scenarios and analyzes its Doppler characteristics. Firstly, the distribution and variation of the Doppler shift of the multipath components are examined from the Doppler power spectrum (DPS). Secondly, the variation of the mean Doppler shift is described. The mean Doppler shift in the head-on driving scenario is found to have the greatest fluctuation, while the Doppler frequency shift in the overtaking is the most stable. Then, the Doppler spread (DOPS) is calculated and analyzed. The Doppler spread varies across different scenarios, and within the same environment, it also shows significant differences due to varying speeds. Finally, a normal distribution model for the Doppler spread is established. This work contributes to modeling the V2V channel in the urban environment.

关键词： Doppler shift Fluctuations Roads Urban areas Vehicular ad hoc networks Europe Gaussian distribution Market research Antennas and propagation Standards

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Experimental Modeling of Power Attenuation Factor for Characterizing Spatial Non-Stationary in XL-MIMO Channels

Experimental Modeling of Power Attenuation Factor for Charac...

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European Conference on Antennas and Propagation, EuCAP

作者： Jie Meng Pan Tang Haiyang Miao Lei Tian Jianhua Zhang State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9788831299107

ISBN: (纸本)9798350366327

Extremely large-scale Multiple-Input Multiple-Output (XL-MIMO) is envisioned as a promising technology for sixth-generation (6G) communication, with the deployment of extremely large-scale antenna arrays at both the transmitter and receiver in XL-MIMO channels resulting in spatial non-stationary (SnS) characteristics. Although numerous channel measurements and models have been proposed focusing on the SnS characteristics of XL-MIMO channels, few low-complexity channel models characterize the characteristics. This paper proposes a low-complexity experimental model based on the power attenuation factor to characterize SnS. In this paper, channel measurements are conducted at 13 GHz in an indoor office. Analysis of the measurement data reveals significant fluctuations in cluster power along the antenna elements due to SnS. The power attenuation factor is used to model the power variations of clusters caused by SnS. The modeling method effectively captures the SnS characteristics. It provides important references for the XL-MIMO channel modeling research and standardization work.

关键词： Antenna measurements 6G mobile communication Power measurement Fluctuations Transmitting antennas Standardization Attenuation measurement Attenuation Channel models Antenna arrays

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Anomaly Detection Method based on Multi-Source Subsequence Multi-View Fusion

Anomaly Detection Method based on Multi-Source Subsequence M...

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2023 IEEE/CIC International Conference on Communications in China, ICCC 2023

作者： Guo, Yizhuo Xu, Peng Liu, Keqi Zhang, Anyi Beijing University of Posts and Telecommunications School of Information and Communication Engineering Beijing China Beijing University of Posts and Telecommunications State Key Lab of Networking and Switching Technology Beijing China

ISBN: (纸本)9798350345384

The integration of multiple sensors in industrial systems and subsequent anomaly detection based on the sensor-collected data has emerged as one of the most popular applications of the Internet of Things. Therefore, it is highly significant to conduct anomaly detection based on multi-source subsequence data. However, existing research either deals with anomaly detection for multi-source data fusion or anomaly detection for subsequences. In this paper, we propose a novel Anomaly Detection method based on multi-source subsequence multi-View data that overcomes the limitations of the existing methods. Specifically, we introduce an improved shape-based subsequence mapping method for the representation of multi-source subsequences, followed by a multi-view based feature fusion matrix construction method. Finally, we propose an anomaly scoring method based on property attribute fusion, which is the first of its kind to introduce a source importance factor that takes into account the importance of different data sources for adjusting the impact weight. Our experimental results demonstrate that the proposed method outperforms traditional anomaly detection methods. © 2023 IEEE.

关键词： Anomaly detection

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Multi-Frequency Channel Measurement in Smart Factories: Comparative Analysis with 3GPP InF Scenarios*

Multi-Frequency Channel Measurement in Smart Factories: Comp...

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IEEE Conference on Vehicular technology (VTC)

作者： Qingmei Mo Yuxiang Zhang Jialin Wang Yameng Liu Zeyong Chai Huiwen Gong Jianhua Zhang State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9798331517786

ISBN: (纸本)9798331517793

Smart factory scenarios in the Industrial Internet of Things (IIoT) introduce novel challenges to wireless communication, characterized by large-scale device interaction, strong reflection, and dense scattering, diverging from typical factories. To ascertain the channel disparities between smart factories and typical factories, we analyze channel characteristics across sub-6 GHz (e.g., 6 GHz) and mmWave frequencies (e.g., 28 and 39 GHz) in smart factory scenarios, establishing a multi-frequency path loss model. Furthermore, the comparison between the large-scale fading characteristics, including path loss and root mean square delay spread (RMS DS), observed in smart factory scenarios and those in the typical indoor factory (InF) scenarios defined by the 3rd-Generation Partnership Project (3GPP). Additionally, channel characteristics of the metal and non-metal scatterer areas in the smart factories are extracted to analyze the impact of metal scatterers on angle spread (AS) and RMS DS.

关键词： Wireless communication Area measurement Metals Scattering Production facilities Reflection Delays 3GPP Smart manufacturing Industrial Internet of Things

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Analysis of Near-Field Effects, Spatial Non-Stationary Characteristics Based on 11-15 GHz Channel Measurement in Indoor Scenario

arXiv

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arXiv 2024年

作者： Miao, Haiyang Tang, Pan Zuo, Weirang Wei, Qi Tian, Lei Zhang, Jianhua State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

In the sixth-generation (6G), with the further expansion of array element number and frequency bands, the wireless communications are expected to operate in the near-field region. The near-field radio communications (NFRC) will become crucial in 6G communication systems. The new mid-band (6-24 GHz) is the 6G potential candidate spectrum. In this paper, we will investigate the channel measurements and characteristics for the emerging NFRC. First, the near-field spherical-wave signal model is derived in detail, and the stationary interval (SI) division method is discussed based on the channel statistical properties. Then, the influence of line-of-sight (LOS) and obstructed-LOS (OLOS) environments on the near-field effects and spatial non-stationary (SnS) characteristic are explored based on the near-field channel measurements at 11-15 GHz band. We hope that this work will give some reference to the NFRC research. Copyright © 2024, The Authors. All rights reserved.

关键词： Radio communication

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Measurement-Based Massive MIMO Channel Characterization in 6 GHz Band for 6G

Measurement-Based Massive MIMO Channel Characterization in 6...

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IEEE Conference on Wireless Communications and networking

作者： Haiyang Miao Pan Tang Jianhua Zhang Lei Tian Huixin Xu Shuo Liu Tianyang Gao Yi Li State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9798350303582

ISBN: (纸本)9798350303599

Massive multiple-input multiple-output (MIMO) is envisioned as a promising technology in 5G-Advanced and sixth-generation (6G) communication. Channel characteristics are important for the development and performance assessment of massive MIMO systems. Besides, the 6 GHz band (5925- 7125 MHz) has rapidly become the focus band of industry and academia at present. Therefore, this paper conducts the massive MIMO channel measurements in 6 GHz band in typical urban scenarios, and focuses on the massive MIMO channel characteristics in 6 GHz band. The important channel characteristic parameters such as power delay profile (PDP), delay spread, angular spread, channel capacity and data transmission rate are obtained and investigated, which are statistically different from Third Generation Partnership Project (3GPP) TR 38.901 model parameters. Besides, the impact of bandwidth on the system is important, and the great bandwidth allocation has the ability to provide higher transmission rates for future communication systems. Based on deeply exploration of the channel characteristics in 6 GHz band, this work hopes to provide some reference for the design and optimization of 6G communication systems.

关键词： 6G mobile communication Channel capacity Massive MIMO Bandwidth Delays Planning Data communication

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Novel Application Creation Paradigm Using Natural Language Compiler Based on LLM

Novel Application Creation Paradigm Using Natural Language C...

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IEEE International Smart Cities Conference (ISC2)

作者： Peng Xu Haoran Wang Chuang Wang Yuewen Liu State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9798350364316

ISBN: (纸本)9798350364323

The development of smart cities requires an increasing demand for diversified applications, thus requiring more convenient ways of application creation. In recent years, the rapid development and applications of Large Language Model (LLM) technology increasingly facilitate its use in application creation. Although “LLM Aided Coding” can reduce the need for developers to have advanced computer skills, it still requires them to master the use of computer programming languages. As a new type of application creation method, “LLM-Enabled Application / AI Agents” can simplify the development process and meet the complex application requirements in smart cities. Developers could create applications using natural language, thus effectively reducing the complexity and workload of application creation. However, these applications still rely on LLM in the execution phase, which greatly limits their operational efficiency and cost. In this paper, we propose a new application creation paradigm using the Natural Language Compiler (NLC) based on LLM. The introduction of NLC allows developers to create and release applications by simply describing the application requirements in natural language and performing simple configurations, without relying on LLM during the application execution phase. NLC draws on the architecture of AI Agents and further introduces Methodology Component to address the issue of inaccuracies and erroneous assumptions in planning due to the lack of factual grounding, thus enhancing the extensibility of planning capabilities. NLC adopts the “register-discover-invoke” mechanism to support the flexible extension of tools. These improvements maintain the convenience of application creation while enabling NLC to have a stronger and more flexible application creation capability, this new application creation paradigm provides a more efficient and flexible solution for smart cities. The source code is available at https://***/free4inno/NLC.

关键词： Hands Runtime environment Smart cities Source coding Scalability Natural languages Programming Extensibility Planning Software development management

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An Enhanced Dynamic Ray Tracing Architecture for Channel Prediction Based on Multipath Bidirectional Geometry and Field Extrapolation

An Enhanced Dynamic Ray Tracing Architecture for Channel Pre...

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IEEE Conference on Global Communications (GLOBECOM)

作者： Yinghe Miao Li Yu Yuxiang Zhang Hongbo Xing Jianhua Zhang State Key Lab of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9798350351255

ISBN: (纸本)9798350351262

With the development of sixth generation (6G) networks toward digitalization and intelligentization of communications, rapid and precise channel prediction is crucial for the network potential release. Interestingly, a dynamic ray tracing (DRT) approach for channel prediction has recently been proposed, which utilizes the results of traditional RT to extrapolate the multipath geometry evolution. However, both the priori environmental data and the regularity in multipath evolution can be further utilized. In this work, an enhanced-dynamic ray tracing (E-DRT) algorithm architecture based on multipath bidirectional extrapolation has been proposed. In terms of accuracy, all available environment information is utilized to predict the birth and death processes of multipath components (MPCs) through bidirectional geometry extrapolation. In terms of efficiency, bidirectional electric field extrapolation is employed based on the evolution regularity of the MPCs’ electric field. The results in a Vehicle-to-Vehicle (V2V) scenario show that E-DRT improves the accuracy of the channel prediction from 68.3% to 94.8% while reducing the runtime by 7.2% compared to DRT.

关键词： Geometry Extrapolation Accuracy Runtime Heuristic algorithms Ray tracing Prediction algorithms Complexity theory Vehicle dynamics Electric fields

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