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AI Enabled Wireless Communications with Real channel measurements:channel Feedback

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Journal of Communications and Information Networks 2020年第3期5卷 310-317页

作者： Jiajia Guo Xiangyi Li Muhan Chen Peiwen Jiang Tingting Yang Weiming Duan Haowen Wang Shi Jin Quan Yu National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China Peng Cheng Laboratory Shenzhen 518000China Laboratory of Broadband Wireless Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 201800China

Artificial intelligence(AI)has shown great potential in wireless communications.AI-empowered communication algorithms have beaten many traditional algorithms through simulations.However,the existing works just use the simulated datasets to train and test the algorithms,which can not represent the power of AI in practical communication systems.Therefore,Peng Cheng Laboratory holds an AI competition,National Artificial Intelligence Competition(NAIC):AI+wireless communications,in which one of the topics is AI-empowered channel feedback system design using practical measurements.In this paper,we give a baseline neural network design,QuanCsiNet,for this competition,and the details of the channel *** shows excellent performance on channel feedback and the complexity of the neural networks is also given.

关键词： NAIC artificial intelligence CSI feedback channel measurements

Astudy of uplink and downlink channel spatial characteristics in an urban micro scenario at 28GHz

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Frontiers of Information Technology & Electronic Engineering 2021年第4期22卷 488-502页

作者： Tao JIANG Jianhua ZHANG Pan TANG Lei TIAN State Key Lab of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

This paper presents an empirical study of the uplink and downlink azimuth angle of arrival(AoA)in an urban micro(UMi)scenario at 28 GHz.At present,most UMi measurements are conducted in the downlink and then the uplink situation is inferred assuming channel reciprocity.Although the channel correlation coefficient of the uplink and downlink can be as high as 0.8,this does not mean that they are the same.Only a real uplink measurement can accurately describe its channel conditions,and this is what this study does.A receiver equipped with a rotatable horn antenna is mounted at the base station and the user terminal,respectively,in simulating the uplink and downlink.To improve the angular resolution,we extract the multipath components(MPCs)using the space-alternating generalized expectation-maximization algorithm.Also,a spatial lobe approach is used to cluster the MPCs in the power angular spectrum.By matching MPCs with objects in the environment,we find that direct propagation and first-order reflections are dominant in line-of-sight and non-line-of-sight cases.By comparing our measurement with those in standard channel models,we verify that the AoA of clusters follows a Gaussian distribution in the uplink and downlink.In addition,a two-dimensional Gaussian distribution for ray AoA and power is established to reflect their correlation.

关键词： channel measurements Millimeter-wave(mmWave) Uplink Downlink Azimuth angle of arrival

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面向6G的信道测量与建模:现状与展望

Frontiers of Information Technology & Electronic Engineering 2020年第1期21卷 39-61页

作者： Jian-hua ZHANG Pan TANG Li YU Tao JIANG Lei TIAN State Key Lab of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

With the commercialization of fifth generation networks worldwide,research into sixth generation(6G)networks has been launched to meet the demands for high data rates and low latency for future services.A wireless propagation channel is the transmission medium to transfer information between the transmitter and the receiver.Moreover,channel properties determine the ultimate performance limit of wireless communication systems.Thus,conducting channel research is a prerequisite to designing 6G wireless communication systems.In this paper,we first introduce several emerging technologies and applications for 6G,such as terahertz communication,industrial Internet of Things,space-air-ground integrated network,and machine learning,and point out the developing trends of 6G channel models.Then,we give a review of channel measurements and models for the technologies and applications.Finally,the outlook for 6G channel measurements and models is discussed.

关键词： channel measurements channel models Sixth generation Terahertz Industrial Internet of Things Space-air-ground integrated network Machine learning

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A novel 3D GBSM for mm Wave MIMO channels

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Science China(Information Sciences) 2018年第10期61卷 198-212页

作者： Jie HUANG Cheng-Xiang WANG Yu LIU Jian SUN Wensheng ZHANG Shandong Provincial Key Lab of Wireless Communication Technologies School of Information Science and Engineering Shandong University Institute of Sensors Signals and Systems School of Engineering & Physical SciencesHeriot-Watt University

In this paper, a novel three dimensional(3 D) wideband geometry-based stochastic model(GBSM) for millimeter wave(mm Wave) multiple-input multiple-output(MIMO) channels is proposed. A homogeneous Poisson point process(PPP) is used to generate the clusters in 3 D space. The transmitter(Tx) and receiver(Rx) are surrounded by two spheres. The scatterers distributed in the two spheres are introduced to mimic the clustering effects of multipath components(MPCs) in delay and angular domains.The large-scale path loss model and line-of-sight(LOS) probability model are taken into account to make the channel model realistic. In addition, mm Wave channel measurements are conducted in an indoor environment. Simulation results based on the two-sphere channel model are compared with measurement results and good agreements are achieved, which validates the proposed channel model. The results indicate that the proposed channel model has good adaptivity and can model the mm Wave channel accurately.

关键词： 3D GBSM mm Wave channels homogeneous PPP LOS probability channel measurements

Improved channel Reciprocity for Secure Communication in Next Generation Wireless Systems

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Computers, Materials & Continua 2021年第5期67卷 2619-2630页

作者： Imtisal Qadeer Muhammad Khurram Ehsan Faculty of Engineering Bahria UniversityLahore CampusLahorePakistan

To secure the wireless connection between devices with low computational power has been a challenging problem due to heterogeneity in operating devices,device to device communication in Internet of Things(IoTs)and 5G wireless systems.Physical layer key generation(PLKG)tackles this secrecy problem by introducing private keys among two connecting devices through wireless medium.In this paper,relative calibration is used as a method to enhance channel reciprocity which in turn increases the performance of the key generation process.channel reciprocity based key generation is emerged as better PLKG methodology to obtain secure wireless connection in IoTs and 5G systems.Circulant deconvolution is proposed as a promising technique for relative calibration to ensure channel reciprocity in comparison to existing techniques Total Least Square(TLS)and Structured Total Least Square(STLS).The proposed deconvolution technique replicates the performance of the STLS by exploiting the possibility of higher information reuse and its lesser computational complexity leads to less processing time in comparison to the STLS.The presented idea is validated by observing the relation between signalto-noise ratio(SNR)and the correlation coefficient of the corresponding channel measurements between communicating parties.

关键词： channel measurements physical layer key generation channel reciprocity Internet of things deconvolution