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On-chip mode-division multiplexing with modal crosstalk mitigation

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On-chip mode-division multiplexing with modal crosstalk miti...

optical Fiber {1. Conference, OFC 2020

作者： Huang, Yetian Zhang, Ruihuan Chen, Haoshuo Huang, Hanzi Zhu, Qingming He, Yu Yuan, Yuan Song, Yingxiong Fontaine, Nicolas K. Ryf, Roland Zhang, Yong Su, Yikai Wang, Min Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication Shanghai Institute for Advanced Communication and Data Science Shanghai University Shanghai200444 China State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University Shanghai200240 China Nokia Bell Labs 791 Holmdel Rd. HolmdelNJ07733 United States

We experimentally demonstrate modal crosstalk mitigation over an on-chip mode-division multiplexing link employing low-coherence matched detection. 20-Gbaud QPSK and 8-PSK mode-multiplexed signals are successfully tra... 详细信息

ISBN: (纸本)9781943580712

关键词： Crosstalk

Degrees of Freedom of Holographic MIMO in Multi-user Near-field Channels

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arXiv 2024年

作者： Chen, Houfeng Yue, Shaohua Di Renzo, Marco Zhang, Hongliang The State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China Université Paris-Saclay CNRS CentraleSupélec Lab-oratoire des Signaux et Systèmes 3 Rue Joliot-Curie Gif-sur-Yvette91192 France King’s College London Centre for Telecommunications Research Department of Engineering LondonWC2R 2LS United Kingdom

Holographic multiple-input multiple-output (HMIMO) is an emerging technology for 6G communications, in which numerous antenna units are integrated in a limited space. As the HMIMO array aperture expands, the near-field region of the array is dramatically enlarged, resulting in more users being located in the near-field region. This creates new opportunities for wireless communications. In this context, the evaluation of the spatial degrees of freedom (DoF) of HMIMO multi-user systems in near-field channels is an open problem, as the analytical methods utilized for evaluating the DoF in far-field channels cannot be directly applied. In this paper, we propose a novel method to calculate the DoF of HMIMO in multi-user near-field channels. We first derive the DoF for a single user in the near field, and then extend the analysis to multi-user scenarios. In this latter scenario, we focus on the impact of spatial blocking between HMIMO users. The derived analytical framework reveals that the DoF of HMIMO in multi-user near-field channels is not in general given by the sum of the DoF of the HMIMO single-user setting because of spatial blocking. Simulation results demonstrate the effectiveness of the proposed method. In the considered case study, the number of DoF reduces by 21.2% on average due to spatial blocking. Copyright © 2024, The Authors. All rights reserved.

关键词： Degrees of freedom (mechanics)

Split Fine-Tuning for Large Language Models in Wireless networks

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arXiv 2025年

作者： Zhang, Songge Cheng, Guoliang Huang, Xinyu Li, Zuguang Wu, Wen Song, Lingyang Shen, Xuemin School of Electronic and Computer Engineering Peking University Shenzhen518000 China Frontier Research Center Pengcheng Laboratory Shenzhen518055 China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China School of Electronic and Computer Engineering Peking University Shenzhen Graduate School Shenzhen518055 China Department of Electrical and Computer Engineering University of Waterloo WaterlooN2L 3G1 Canada

Fine-tuning is the process of adapting the pre-trained large language models (LLMs) for downstream tasks. Due to substantial parameters, fine-tuning LLMs on mobile devices demands considerable memory resources, and suffers from high communication overhead and long fine-tuning delay. In this paper, we propose an efficient LLM fine-tuning scheme in wireless {1., named Split Fine-Tuning (SFT), which can accommodate LLM fine-tuning on mobile devices. Specifically, an LLM is split into a server-side part on the edge server and a device-side part on the mobile device to satisfy the device-side memory constraint. All devices share a server-side model and perform parallel fine-tuning to reduce fine-tuning delay. In addition, to reduce significant communication overhead incurred by data exchange between devices and the edge server, we propose a data compression scheme by jointly leveraging sparsification, stochastic quantization, and lossless encoding methods. Furthermore, we formulate a fine-tuning delay minimization problem under accuracy and memory constraints, taking device heterogeneity and channel dynamics into account. To solve the problem, the nonlinear mixed-integer problem is decoupled into two subproblems in different timescales. The two-timescale resource management algorithm is proposed to jointly optimize the compression rate and transformer block allocation in the large timescale using the augmented Lagrangian method, and determine spectrum resource allocation in the small timescale via sequential quadratic programming. Extensive simulation results demonstrate that the proposed scheme can reduce the fine-tuning delay by up to 80.2% and communication overhead by 93.6% compared to state-of-the-art benchmarks, while satisfying device-side memory and model accuracy constraints. Copyright © 2025, The Authors. All rights reserved.

关键词： Quadratic programming

High-performance III-V/Si3N4 O-band External Cavity Tunable Laser

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High-performance III-V/Si3N4 O-band External Cavity Tunable ...

Conference on Lasers and Electro-Optics (CLEO)

作者： Yuyao Guo Xinhang Li Minhui Jin Chuxin Liu Weihan Xu Liangjun Lu Jingya Xie Jianping Chen Linjie Zhou Department of Electronic Engineering State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University Shanghai China SJTU-Pinghu Institute of Intelligent Optoelectronics Pinghu China Terahertz Technology Innovation Research Institute Terahertz Spectrum and Imaging Technology Cooperative Innovation Center Shanghai Key Lab of Modern Optical System University of Shanghai for Science and Technology Shanghai China

We present a III-V/Si 3 N 4 O-band hybrid laser, which shows a high output power of 42 mW, wide tuning range of 62 nm with side-mode suppression ratio >50 dB, and narrow intrinsic linewidth of ~600 Hz.

ISBN: (数字)9781957171050

ISBN: (纸本)9781665466660

关键词： Power lasers Lasers and electrooptics Hybrid power systems Laser tuning Electrooptical waveguides Power generation

Block-Wise Index Modulation and Receiver Design for High-Mobility OTFS communications

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arXiv 2023年

作者： Qian, Mi Ji, Fei Ge, Yao Wen, Miaowen Cheng, Xiang Poor, H. Vincent The School of Electronic and Information Engineering South China University of Technology Guangzhou510641 China The Continental-NTU Corporate Lab Nanyang Technological University Singapore The State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronics School of Electronics Engineering and Computer Science Peking University Beijing100871 China The Department of Electrical and Computer Engineering Princeton University PrincetonNJ08544 United States

As a promising technique for high-mobility wireless communications, orthogonal time frequency space (OTFS) has been proved to enjoy excellent advantages with respect to traditional orthogonal frequency division multiplexing (OFDM). Although multiple studies have considered index modulation (IM) based OTFS (IM-OTFS) schemes to further improve system performance, a challenging and open problem is the development of effective IM schemes and efficient receivers for practical OTFS {1. that must operate in the presence of channel delays and Doppler shifts. In this paper, we propose two novel block-wise IM schemes for OTFS {1., named delay-IM with OTFS (DeIM-OTFS) and Doppler-IM with OTFS (DoIM-OTFS), where a block of delay/Doppler resource bins are activated simultaneously. Based on a maximum likelihood (ML) detector, we analyze upper bounds on the average bit error rates for the proposed DeIM-OTFS and DoIM-OTFS schemes, and verify their performance advantages over the existing IM-OTFS {1.. We also develop a multi-layer joint symbol and activation pattern detection (MLJSAPD) algorithm and a customized message passing detection (CMPD) algorithm for our proposed DeIM-OTFS and DoIM-OTFS {1. with low complexity. Simulation results demonstrate that our proposed MLJSAPD and CMPD algorithms can achieve desired performance with robustness to the imperfect channel state information (CSI). © 2023, CC BY.

关键词： Message passing

Intelligent Multi-Modal Sensing-communication Integration: Synesthesia of Machines

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arXiv 2023年

作者： Cheng, Xiang Zhang, Haotian Zhang, Jianan Gao, Shijian Li, Sijiang Huang, Ziwei Bai, Lu Yang, Zonghui Zheng, Xinhu Yang, Liuqing The State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China The Samsung Semiconductor Samsung SoC Research and Development Lab San DiegoCA92121 United States Shandong University Jinan250100 China Guangzhou510000 China Guangzhou510000 China The Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Hong Kong

In the era of sixth-generation (6G) wireless communications, integrated sensing and communications (ISAC) is recognized as a promising solution to upgrade the physical system by endowing wireless communications with sensing capability. Existing ISAC is mainly oriented to static scenarios with radio-frequency (RF) sensors being the primary participants, thus lacking a comprehensive environment feature characterization and facing a severe performance bottleneck in dynamic environments. To date, extensive surveys on ISAC have been conducted but are limited to summarizing RF-based radar sensing. Currently, some research efforts have been devoted to exploring multi-modal sensing-communication integration but still lack a comprehensive review. To fill the gap, we embark on an initial endeavor with the goal of establishing a unified framework of intelligent multi-modal sensing-communication integration by generalizing the concept of ISAC and providing a comprehensive review under this framework. Inspired by the human synesthesia, the so-termed Synesthesia of Machines (SoM) gives the clearest cognition of such an intelligent integration and details its paradigm for the first time. We commence by justifying the necessity and potential of the new paradigm. Subsequently, we offer a rigorous definition of SoM and zoom into the detailed paradigm, which is summarized as three operational modes realizing the integration. To facilitate SoM research, we overview the prerequisite of SoM research, that is, mixed multi-modal (MMM) datasets, and introduce our work. Built upon the MMM datasets, we introduce the mapping relationships between multi-modal sensing and communications, and discuss how channel modeling can be customized to support the exploration of such relationships. Afterward, aiming at giving a comprehensive survey on the current research status of multi-modal sensing-communication integration, we cover the technological review on SoM-enhance-based and SoM-concert-based app

关键词： Beamforming

A hybrid-integrated external cavity laser with ultra-wide wavelength tuning range and high side-mode suppression

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A hybrid-integrated external cavity laser with ultra-wide wa...

optical Fiber {1. (OFC) Conference

作者： Yuyao Guo Xinhang Li Weihan Xu Chuxin Liu Minhui Jin Liangjun Lu Jingya Xie Anton Stroganov Jianping Chen Linjie Zhou State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Institute for Advanced Communication and Data Science Shanghai Jiao Tong University Shanghai China SJTU-Pinghu Institute of Intelligent Optoelectronics Pinghu China Terahertz Technology Innovation Research Institute Terahertz Spectrum and Imaging Technology Cooperative Innovation Center Shanghai Key Lab of Modern Optical System University of Shanghai for Science and Technology Shanghai China LIGENTEC SA EPFL Innovation Park Bâtiment L Ecublens Switzerland

We present a III-V/Si 3 N 4 hybrid-integrated tunable laser. The laser shows a record of ~1.0-nm tuning range with a side mode suppression ratio above 64 dB and an intrinsic linewidth below 2.8 kHz. &#1.9; 2022 The A... 详细信息

ISBN: (纸本)9781557524669

关键词： Performance evaluation Couplings Laser modes Optics optical fiber {1. Broadband communication Laser tuning

Silicon Integrated Low-Loss 4-Channel 5-Bit optical True-Time Delay Lines

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Silicon Integrated Low-Loss 4-Channel 5-Bit Optical True-Tim...

OptoElectronics and communications Conference, OECC

作者： Yuanbin Liu Liangjun Lu Jianping Chen Linjie Zhou Department of Electronic Engineering State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Key Lab of Navigation and Location Services Shanghai Institute for Advanced Communication and Data Science Shanghai Jiao Tong University Shanghai China SJTU-Pinghu Institute of Intelligent Optoelectronics Pinghu China

We demonstrate 4-channel tunable optical delay lines with delay $\gt500$ ps and delay error $\lt \pm 1. ps. The delay loss is 3 dB/ns and the delay deviation is less than 1.ps among 4 channels. &#1.9; 2021.The Author(s)

ISBN: (数字)9781943580927

ISBN: (纸本)9781665400060

关键词： optical losses Phased arrays Integrated optics Insertion loss Delay lines Adaptive optics Silicon

Improving the frequency chirp linearity of a frequency-modulated continuous-wave laser

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Improving the frequency chirp linearity of a frequency-modul...

OptoElectronics and communications Conference, OECC

作者： Chuxin Liu Yuyao Guo Weihan Xu Liangjun Lu Jianping Chen Linjie Zhou Department of Electronic Engineering State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Key Lab of Navigation and Location Services Shanghai Institute for Advanced Communication and Data Science Shanghai Jiao Tong University Shanghai China SJTU-Pinghu Institute of Intelligent Optoelectronics Pinghu China

We propose a novel driving signal pre-distortion method to improve the frequency chirp linearity of an InP/Si 3 N 4 hybrid-integrated external cavity laser. The measured chirp linearity is increased from 87.3% to 99.7... 详细信息

ISBN: (数字)9781943580927

ISBN: (纸本)9781665400060

关键词： Laser radar Chirp Lasers Linearity Measurement by laser beam Distance measurement Behavioral sciences