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Macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

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National Science Review 2024年第03期11卷 159-171页

作者： Rui Wen Shao Jun Wei Wu Zheng Xing Wang Hui Xu Han Qing Yang Qiang Cheng Tie Jun Cui Institute of electromagnetic Space Southeast University State Key laboratory of Millimeter Waves Southeast University Peng Cheng laboratory Pazhou laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model

Demonstration of radar-aided flexible communication in a photonics-based W-band distributed integrated sensing and communication system for 6G

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Chinese Optics Letters 2024年第4期22卷 119-124页

作者：贾俊连董博宇陶理施剑阳迟楠张俊文 Key laboratory of EMW Information(MoE) Fudan UniversityShanghai 200433China Shanghai ERC of LEO Satellite communication and Applications Shanghai CIC of LEO Satellite Communication TechnologyShanghai 200433China Science and Technology on electromagnetic compatibility laboratory China Ship Development and Design CentreWuhan 430000China Peng Cheng laboratory Shenzhen 518055China

This paper experimentally demonstrates a distributed photonics-based W-band integrated sensing and communication(ISAC) system, in which radar sensing can aid the communication links in alignment and data rate estimation. As a proof-of-concept, the ISAC system locates the users, guides the alignment, and sets a communication link with the estimated highest data rate. A peak net data rate of 68.6 Gbit/s and a target sensing with a less-than-1-cm error and a sub-2-cm resolution have been tested over a 10-km fiber and a 1.15-m free space transmission in the photonics-based W-band ISAC system. The achievable net data rates of the users at different locations estimated by sensing are experimentally verified.

关键词： integrated sensing and communication photonics-aided technique W-band radar-aided flexible communication

Demonstration of LDPC-coded PS-64QAM OFDM employing novel bit-class distribution matching in a W-band RoF system

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Chinese Optics Letters 2024年第8期 40-45页

作者：赵海涛徐邦宁荀位任建新陈帅东张龙赵利刘博 School of communication and Information Engineering Nanjing University of Posts and Telecommunications Institute of Optics and Electronics Nanjing University of Information Science&Technology Key laboratory for Information Science of electromagnetic Waves (MoE) Fudan University

In this work, we proposed and experimentally demonstrated a novel probabilistic shaping(PS) 64-ary quadrature amplitude modulation(QAM) orthogonal frequency division multiplexing(OFDM) with low-density parity-check(LDPC)-coded modulation in a W-band radio-over-fiber(RoF) system using envelope detection. The proposed PS scheme has the advantages of no complex multiplication and division operations and low hardware implementation complexity. In our experiments, the two-stage bit weight distribution matching-based PS-64QAM OFDM signals with a rate of 28.13 Gb/s transmission over 4 m wireless + 45-km standard single-mode fiber transmission can be achieved. The system performance is investigated under one LDPC code rate(3/4) and two PS parameter values (k = 3 and 9). The experimental results show that the receiver power sensitivity and the system fiber nonlinear effect tolerance can be significantly improved compared with uniformly distributed OFDM signals.

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A Novel Pulse Design Based on Hermite Functions for UWB communications

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The Journal of China Universities of Posts and Telecommunications 2006年第1期13卷 49-52页

作者： JIANG Guang-xing ZHU Hong-bo CAO Wei wireless communication and electromagnetic compatibility laboratory Nanjing University of Posts and Telecommunications Nanjing 210003 P.R. China

This paper presents the design of a class of pulses that are based on Hermite functions for ultra-wideband communication systems. The presented class of pulses can not only meet the power spectral emission constraints of federal communications commission, but also have a short duration for multiple accesses. This paper gives closed form expressions of auto-and cross-correlation functions of the proposed pulses, which can be used to evaluate the performance of the correlator receiver. Furthermore, the paper investigates, under various channel conditions, the spectrum characteristic and the bit error rate of the pulses＇ wave forms. The investigation conditions include additive white Gaussian noise channels, multipleaccess interference channels, and fading multipath channels. Our results indicate that our systematic algorithm is flexible for designing ultra-wideband pulses that conform to spectral emission constraints and offer good bit error rate performance.

关键词： pulse design UWB Hermite functions multiple access multipath

Photonics-assisted THz wireless communication enabled by wide-bandwidth packaged backilluminated modified uni-traveling-carrier photodiode

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Opto-Electronic Science 2024年第7期3卷 20-29页

作者： Yuxin Tian Boyu Dong Yaxuan Li Bing Xiong Junwen Zhang Changzheng Sun Zhibiao Hao Jian Wang Lai Wang Yanjun Han Hongtao Li Lin Gan Nan Chi Yi Luo Beijing National Research Center for Information Science and Technology(BNRist) Department of Electronic EngineeringTsinghua UniversityBeijing 100084China Key laboratory of Information Science of electromagnetic Waves(MoE) Department of Communication Science and EngineeringFudan UniversityShanghai 200433China Flexible Intelligent Optoelectronic Device and Technology Center Institute of Flexible Electronics Technology of THUJiaxing 314000China

This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless *** optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation *** passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide *** packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 *** wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively.

关键词： modified uni-traveling-carrier photodiode integrated bias-tee E-plane probe flat frequency response high saturation power WR-5 output THz wireless communications

Stochastic Gradient Compression for Federated Learning over wireless Network

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China communications 2024年第4期21卷 230-247页

作者： Lin Xiaohan Liu Yuan Chen Fangjiong Huang Yang Ge Xiaohu School of Electronic and Information Engineering South China University of TechnologyGuangzhou 510641China Key laboratory of Dynamic Cognitive System of electromagnetic Spectrum Space Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China School of Electronic Information and communications Huazhong University of Science and TechnologyWuhan 430074China

As a mature distributed machine learning paradigm,federated learning enables wireless edge devices to collaboratively train a shared AI-model by stochastic gradient descent(SGD).However,devices need to upload high-dimensional stochastic gradients to edge server in training,which cause severe communication *** address this problem,we compress the communication by sparsifying and quantizing the stochastic gradients of edge *** first derive a closed form of the communication compression in terms of sparsification and quantization ***,the convergence rate of this communicationcompressed system is analyzed and several insights are ***,we formulate and deal with the quantization resource allocation problem for the goal of minimizing the convergence upper bound,under the constraint of multiple-access channel *** show that the proposed scheme outperforms the benchmarks.

关键词： federated learning gradient compression quantization resource allocation stochastic gradient descent(SGD)

Performance Analysis and Optimization of Energy Harvesting Modulation for Multi-User Integrated Data and Energy Transfer

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China communications 2024年第1期21卷 148-162页

作者： Yizhe Zhao Yanliang Wu Jie Hu Kun Yang School of Information and communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

Integrated data and energy transfer(IDET)enables the electromagnetic waves to transmit wireless energy at the same time of data delivery for lowpower *** this paper,an energy harvesting modulation(EHM)assisted multi-user IDET system is studied,where all the received signals at the users are exploited for energy harvesting without the degradation of wireless data transfer(WDT)*** joint IDET performance is then analysed theoretically by conceiving a practical time-dependent wireless *** the aid of the AO based algorithm,the average effective data rate among users are maximized by ensuring the BER and the wireless energy transfer(WET)*** results validate and evaluate the IDET performance of the EHM assisted system,which also demonstrates that the optimal number of user clusters and IDET time slots should be allocated,in order to improve the WET and WDT performance.

关键词： energy harvesting modulation(EHM) integrated data and energy transfer(IDET) performance analysis wireless data transfer(WDT) wireless energy transfer(WET)

一种小型化人工表面等离激元传感系统——实现自适应和高灵敏的气体检测

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Engineering 2024年第4期35卷 86-94页

作者： Xuanru Zhang Jia Wen Zhu Tie Jun Cui State Key laboratory of Millimeter Waves and Institute of electromagnetic Space Southeast UniversityNanjing 210096China School of Information Science and Engineering Southeast UniversityNanjing 210096China School of Microelectronics Southeast UniversityNanjing 210096China

Resonantly enhanced dielectric sensing has superior sensitivity and accuracy because the signal is measured from relative resonance shifts that are immune to signal *** applications in the Internet of Things(IoT),accurate detection of resonance frequency shifts using a compact circuit is in high *** proposed an ultracompact integrated sensing system that merges a spoof surface plasmon resonance sensor with signal detection,processing,and wireless communication.A softwaredefined scheme was developed to track the resonance shift,which minimized the hardware circuit and made the detection adaptive to the target resonance.A microwave spoof surface plasmon resonator was designed to enhance sensitivity and resonance *** integrated sensing system was constructed on a printed circuit board with dimensions of 1.8 cm×1.2 cm and connected to a smartphone wirelessly through Bluetooth,working in both frequency scanning mode and resonance tracking mode and achieving a signal-to-noise ratio of 69 dB in acetone vapor *** study provides an ultracompact,accurate,adaptive,sensitive,and wireless solution for resonant sensors in the IoT.

关键词： Spoof surface plasmons Internet of Things Integrated sensing Resonance tracking Microwave sensing

Intelligent secure near-field communication

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Science China(Information Sciences) 2024年第9期67卷 340-341页

作者： Nan ZHANG Jifa ZHANG Chengwen XING Na DENG Nan ZHAO School of Information and communication Engineering Dalian University of Technology School of Information and Electronics Beijing Institute of Technology

The research and development efforts for the sixth generation(6G) wireless communication are underway to fulfill the growing demands for wireless communications. 6G is expected to become the key enabler for diverse new applications and services [1]. To achieve the excellent performance, 6G will implement extremely large-scale antenna arrays(ELAAs), terahertz [2], and new types of antennas with metamaterials, leading to a paradigm shift for the electromagnetic characteristics.

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