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Design and Implementation of Nonlinear Precoding for MIMO-SDMA Toward 6G Wireless

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China communications 2024年第1期21卷 69-87页

作者： Chaowu Wu Yue Xiao Shu Fang Gang Wu National Key laboratory of Wireless communications University of Electronic Science and Technology of ChinaChengdu 611731China

In this paper,we present a novel and robust nonlinear precoding(NLP)design and detection structure specifically tailored for multiple-input multipleoutput space division multiple access(MIMO-SDMA)systems toward 6G *** approach aims to effectively mitigate the impact of imperfect channel estimation by leveraging the channel fluctuation mean square error(MSE)for reconstructing a highly accurate precoding matrix at the ***,we introduce a simplified receiver structure that eliminates the need for equalization,resulting in reduced interference and notable enhancements in overall system *** conduct both computer simulations and experimental tests to validate the efficacy of our proposed *** results reveals that the proposed NLP scheme offers significant performance improvements,making it particularly well-suited for the forthcoming 6G wireless.

关键词： MIMO-SDMA nonlinear precoding Tomlinson-Harashima precoding(THP) vector perturbation(VP)

Layered Coded Cache Placement and Cooperative Delivery with Sharing Links in Satellite-Terrestrial Integrated Networks

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China communications 2024年第3期21卷 217-229页

作者： Gu Shushi Chen Zihan Wu Yaonan Zhang Qinyu Wang Ye School of Electronic and Information Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Guangdong Provincial Key laboratory of Aerospace Communication and Networking Technology Shenzhen 518055China Broadband communications research Department Pengcheng LaboratoryShenzhen 518052China

Cooperative utilization of multidimensional resources including cache, power and spectrum in satellite-terrestrial integrated networks(STINs) can provide a feasible approach for massive streaming media content delivery over the seamless global coverage area. However, the on-board supportable resources of a single satellite are extremely limited and lack of interaction with others. In this paper, we design a network model with two-layered cache deployment, i.e., satellite layer and ground base station layer, and two types of sharing links, i.e., terrestrial-satellite sharing(TSS) links and inter-satellite sharing(ISS) links, to enhance the capability of cooperative delivery over STINs. Thus, we use rateless codes for the content divided-packet transmission, and derive the total energy efficiency(EE) in the whole transmission procedure, which is defined as the ratio of traffic offloading and energy consumption. We formulate two optimization problems about maximizing EE in different sharing scenarios(only TSS and TSS-ISS),and propose two optimized algorithms to obtain the optimal content placement matrixes, *** results demonstrate that, enabling sharing links with optimized cache placement have more than 2 times improvement of EE performance than other traditional placement schemes. Particularly, TSS-ISS schemes have the higher EE performance than only TSS schemes under the conditions of enough number of satellites and smaller inter-satellite distances.

关键词： coded content placement cooperative delivery energy efficiency sharing links STINs

Computing-aware network (CAN): a systematic design of computing and network convergence

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Frontiers of Information Technology & Electronic Engineering 2024年第5期25卷 633-644页

作者： Xiaoyun WANG Xiaodong DUAN Kehan YAO Tao SUN Peng LIU Hongwei YANG Zhiqiang LI China Mobile communications Corporation Beijing 100032China China Mobile research Institute Beijing 100053China

The coverage of network resources is increasingly extensive,and computing resources have likewise gradually become fundamental infrastructures,providing ubiquitous computing ***,in wide area networks(WANs),the underlying network and computing resources are not closely investigated or co-designed,and there are still problems reflected in slow computing service scheduling,inflexible data distribution,and inefficient data transmission.

关键词： computing network service

Free-moving-state microscopic imaging of cerebral oxygenation and hemodynamics with a photoacoustic fiberscope

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Light(Science & Applications) 2024年第1期13卷 33-46页

作者： Xiaoxuan Zhong Yizhi Liang Xiaoyu Wang Haoying Lan Xue Bai Long Jin Bai-Ou Guan Guangdong Provincial Key laboratory of Optical Fiber Sensing and communications Institute of Photonics TechnologyJinan UniversityGuangzhou510632China

We report the development of a head-mounted photoacoustic fiberscope for cerebral imaging in a freely behaving *** 4.5-gram imaging probe has a 9-µm lateral resolution and 0.2-Hz frame rate over a 1.2-mm wide *** probe can continuously monitor cerebral oxygenation and hemodynamic responses at single-vessel resolution,showing significantly different cerebrovascular responses to external stimuli under anesthesia and in the freely moving *** example,when subjected to high-concentration CO_(2) respiration,enhanced oxygenation to compensate for hypercapnia can be visualized due to cerebral regulation in the freely moving *** studies exhibit significantly weakened compensation capabilities in obese *** new imaging modality can be used for investigating both normal and pathological cerebrovascular functions and shows great promise for studying cerebral activity,disorders and their treatments.

关键词： cerebral anesthesia moving

Inverse-designed Jones matrix metasurfaces for high-performance meta-polarizers

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Chinese Optics Letters 2024年第2期22卷 192-199页

作者：王志强李枫竣邓倩媚万舟李向平邓子岚 Guangdong Provincial Key laboratory of Optical Fiber Sensing and communications Institute of Photonics TechnologyJinan UniversityGuangzhou 510632China

Polarizers have always been an important optical component for optical engineering and have played an indispensable part of polarization imaging *** polarizers provide an excellent platform to achieve miniaturization,high resolution,and low cost of polarization imaging ***,we proposed freeform metasurface polarizers derived by adjoint-based inverse design of a full-Jones matrix with gradient-descent *** designed multiple freeform polarizers with different filtered states of polarization(SOPs),including circular polarizers,elliptical polarizers,and linear polarizers that could cover the full Poincaré*** that near-unitary polarization dichroism and the ultrahigh polarization extinction ratio(ER)reaching 50 d B were achieved for optimized circular *** multiple freeform polarizers with filtered polarization state locating at four vertices of an inscribed regular tetrahedron of the Poincarésphere are designed to form a full-Stokes parameters micropolarizer *** work provides a novel approach,we believe,for the design of meta-polarizers that may have potential applications in polarization imaging,polarization detection,and communication.

关键词： metasurface inverse design Jones matrix polarization imaging

Beyond 600G fiber-THz wireless seamless integration system employing cascaded MIMO equalizers

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Science China(Technological Sciences) 2024年第7期67卷 2274-2276页

作者： DING JunJie TONG WeiDong LI XinTong ZHANG Zheng ZHANG Jiao CAI YuanCheng LEI MingZheng HUA BingChang CHEN XingYu YU JianJun ZHU Min Purple Mountain Laboratories Nanjing 211111China National Mobile communications research laboratory Southeast UniversityNanjing 210096China Fudan University Shanghai 200433China

Terahertz(THz)-wave communication, with sufficient spectrum resources(0.3 THz~10 THz), can meet the needs of future 6G large-capacity mobile communication services[1-9]. Recently, the seamless integration of existing ... 详细信息

关键词： communication fiber wireless

Flocking fragmentation formulation for a multi-robot system under multi-hop and lossy ad hoc networks

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Frontiers of Information Technology & Electronic Engineering 2024年第8期25卷 1057-1076页

作者： Silan LI Shengyu ZHANG Tao JIANG The research Center of 6G Mobile communications School of Cyber Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Wuhan National laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

We investigate the impact of network topology characteristics on focking fragmentation for a multi-robot system under a multi-hop and lossy ad hoc network,including the network's hop count features and information's successful transmission probability(STP).Specifically,we first propose a distributed communication calculation execution protocol to describe the practical interaction and control process in the ad hoc network based multi-robot system,where focking control is realized by a discrete-time Olfati-Saber model incorporating STP-related ***,we develop a fragmentation prediction model(FPM)to formulate the impact of hop count features on fragmentation for specific focking *** model identifies the critical system and network features that are associated with *** considering general focking scenarios affected by both hop count features and STP,we formulate the flocking fragmentation probability(FFP)by a data fitting model based on the back propagation neural network,whose input is extracted from the *** FFP formulation quantifies the impact of key network topology characteristics on fragmentation *** results verify the effectiveness and accuracy of the proposed prediction model and FFP formulation,and several guidelines for constructing the multi-robot ad hoc network are concluded.

关键词： Multi-robot flocking Flocking fragmentation probability Fragmentation prediction Multi-robot communication networks

Empowering over-the-air personalized federated learning via RIS

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Science China(Information Sciences) 2024年

作者： Wei SHI Jiacheng YAO Jindan XU Wei XU Lexi XU Chunming ZHAO National Mobile communications research laboratory Southeast University Purple Mountain Laboratories School of Electrical and Electronics Engineering Nanyang Technological University research Institute China United Network Communications Corporation

Federated learning (FL) is a promising distributed learning approach due to its privacy-enhancing characteristic [1–3].To enhance communication efficiency of FL, over-the-air computation (AirComp) has emerged as a key technique by exploiting the waveform superposition property of multiple access channels [4, 5]. Although AirComp-enabled FL(AirFL) offers significant performance gains, it does not address the data heterogeneity in most real-life FL scenarios with non-independent and identically distributed local datasets. Such data heterogeneity hinders the generalization of a single global consensus model. To this end, preliminary works have been made to develop a personalized AirFL framework via clustering algorithms, where different models are trained for different clusters under the orchestration of the parameter server (PS)[6, 7]. However, this personalized framework requires large-scale antennas to combat interference, leading to a significant escalation in hardware cost.

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Statistical Channel Modeling for Indoor VLC communications Based on Channel Measurements

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China communications 2024年第1期21卷 131-147页

作者： Shuo Liu Pan Tang Jianhua Zhang Yue Yin Yu Tong Baobao Liu Guangyi Liu Liang Xia State Key laboratory of Information Photonics and Optical communications Beijing University of Posts and TelecommunicationsBeijing 100876China State Key laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China China Mobile research Institute Beijing 100053China

Visible light communication(VLC)has attracted much attention in the research of sixthgeneration(6G)***,channel modeling is the foundation for designing efficient and robust VLC *** this paper,we present extensive VLC channel measurement campaigns in indoor environments,i.e.,an office and a *** on the measured data,the large-scale fading characteristics and multipath-related characteristics,including omnidirectional optical path loss(OPL),K-factor,power angular spectrum(PAS),angle spread(AS),and clustering characteristics,are analyzed and modeled through a statistical *** on the extracted statistics of the above-mentioned channel characteristics,we propose a statistical spatial channel model(SSCM)capable of modeling multipath in the spatial ***,the simulated statistics of the proposed model are compared with the measured *** instance,in the office,the simulated path loss exponent(PLE)and the measured PLE are 1.96and 1.97,***,the simulated medians of AS and measured medians of AS are 25.94°and 24.84°,***,the fact that the simulated results fit well with measured results has demonstrated the accuracy of our SSCM.

关键词： channel characteristics channel measurement channel modeling 6G spatial lobe VLC