- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Sao Paulo, Brazil (2019.10.7-2019.10.9)] 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Comparative Study of 1-Tb/s Single Laser Coherent Optical Systems based on OFDM and Nyquist FDM
摘要： Two multiplexing techniques, digitally frequency multiplexed Nyquist FDM and OFDM, are evaluated in high-data rate coherent optical transmissions. Simulations are carried out to achieve a net data rate of 1 Tb/s through dual-polarization 64QAM and 256QAM at 100 GBd and 75 GBd, respectively. The systems’ performance were evaluated in terms of OSNR versus Tx and Rx laser linewidths, number of subcarriers, and DAC/ADC quantization and bandwidths. Despite similar performance for both techniques, CO-NFDM may allow a lower-cost implementation.
关键词： Metro,OFDM,Long-haul,coherent detection,digital signal processing,NFDM
更新于2025-09-16 10:30:52
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Sub-Picosecond Optical Switch over Entire C-Band by Using Nonlinear Optical Loop Mirror
摘要： We describe 650 fs optical switching over the entire C-band using a low walk-off nonlinear optical loop mirror (NOLM). Error-free 320 Gbaud OTDM demultiplexing was successfully demonstrated from 1528 to 1565 nm.
关键词： Multiplexing and demultiplexing techniques including OTDM,OCDM and SDM,OFDM,Optical transmitter and receiver subsystems
更新于2025-09-16 10:30:52
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Sub-carrier Loading Strategies for DCO-OFDM LED Communication
摘要： LEDs, particularly those used for Visible Light Communications (VLC), have a limited bandwidth, while above their 3 dB bandwidth, the roll-off is relatively gentle. If the modulation bandwidth would be limited to the 3 dB LED bandwidth, the achievable rate would be unacceptably constrained. Hence, effective communication systems need to optimize the use of bandwidth significantly above this 3 dB point. Orthogonal Frequency Division Multiplexing (OFDM) is a popular method to fine-tune the amount of power and constellation as a function of the channel response over different frequencies. Various power and bit loading strategies have been proposed and simulated in literature, but their performance was not captured in expressions. This manuscript derives these for optimal waterfilling, uniform and pre-emphasized power loading for the LED channel, that severely attenuates high frequencies. We also investigate the influence of practical discrete constellations and verify our new results experimentally. Interestingly, simple uniform loading only falls less than 1～2% short of the throughput achieved by waterfilling, but when we restrict OFDM to discrete QAM constellation sizes, the penalty for uniform loading is 1.5 dB. Inspired by the good performance of uniform power loading, we propose an algorithm to find the best discrete bit loading for uniform power within an optimized band. As pre-emphasis is nonetheless attractive because a flattened channel does not need adaptive sub-carrier loading, we quantify its penalty. This can be modest provided that the system can adapt its transmit bandwidth, thereby adaptively switching upper sub-carriers to zero power.
关键词： Orthogonal Frequency Division Multiplexing (OFDM),pre-emphasis,power loading strategies,LED channel,QAM constellation sizes,uniform loading,waterfilling,Visible Light Communications (VLC)
更新于2025-09-16 10:30:52
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Realization of real‐time OFDM‐based visible light communication using an InGaN/GaN multiquantum‐wells LED
摘要： This paper presents a real-time OFDM-based visible light communication (VLC) system utilizing a single InGaN/GaN multiquantum-wells (MQWs) light emitting diode (LED). An MQWs LED with 3 dB electrical bandwidth of 23.8 MHz is developed as the transmitting device. Orthogonal frequency division multiplexing (OFDM) is employed to ensure the LED bandwidth is fully used, and the system is designed and implemented on a field-programmable gate array platform to realize real-time communication. The real-time OFDM-VLC system achieves a rate of 96 Mbit/s at the distance of 2 m, and the bit error ratio (BER) is 2.25 × 10?3, which is below the forward error correction (FEC) limit.
关键词： OFDM,Real-time processing,Visible light communication,InGaN/GaN MQWs LED,FPGA
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Novel NOMA System for Optical Communications Based on OFDM/OQAM
摘要： We present a NOMA-based OFDM/OQAM system theoretically in this paper. Our method outperformed conventional OFDM system on the total user throughput and spectral efficiency evidently. The proposal has been validated by theoretical derivation and numerical simulation results.
关键词： spectral efficiency,OFDM/OQAM,NOMA
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Volterra-based fiber nonlinearity impairment modeling for OFDM/OQAM systems
摘要： In this paper, we have reported for the first time the fiber nonlinearity application of Volterra-based impairment modeling for OFDM/OQAM systems. Based the proposed model, a novel compensation method can be presented by simulations later.
关键词： Digital signal processing techniques for optical communications,transmission impairments and their mitigations,multiplexing and demultiplexing techniques including OTDM, OFDM, OCDM and SDM
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Post Equalization Scheme Based on Deep Neural Network for a Probabilistic Shaping 128 QAM DFT-S OFDM Signal in Underwater Visible Light Communication System
摘要： We have presented a post equalization scheme based on Deep Neural Network (DNN) for DFT-S OFDM modulation using (PS) technique in underwater visible light communication (VLC) system. By this method, we successfully demonstrated a data rate of 1.74Gbit/s PS128QAM DFT-S OFDM modulation over 1.2meter underwater optical transmission with bit error rate (BER) below 7% FEC threshold of 3.8×10-3. Compared to the typical PS128QAM DFT-S OFDM modulation without DNN, the proposed method would lead to an improvement of system capacity of 5.4% by increasing the data rate by 90 Mbps. The experimental results validate that the proposed DNN-based post equalization scheme for odd order QAM PS technique can be a promising solution for future high speed underwater VLC system.
关键词： Probabilistic Shaping (PS),odd order QAM,Deep Neural Network (DNN),Underwater VLC,Discrete Fourier Transform-Spread (DFT-S) OFDM
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Machine Learning Scheme for Geometrically-shaped Constellation Classification utilizing Support Vector Machine in Multi-access Internet of Vehicle Lighting
摘要： In this paper, we propose a multi-access Internet of Vehicles (IoV) scheme based on multi-band DFTS-OFDM VLC system. The experimental results show that with the bandwidth of 62.5MHz, the dynamic range was enhanced 1.6 dBm employing SVM in hexagonal constellation Geometrically-shaped (GS) 16QAM and the overall capacity is 250Mbps.
关键词： discrete Fourier transform spread (DFT-S),Geometrically-shaped,optical orthogonal frequency division multiplexing (OFDM),Visible light communication,Internet of Vehicles,Support vector machine
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - A 375Mb/s Real-time Internet of Vehicles System Based on Automotive Headlight Utilizing OFDM-64QAM Modulation Format
摘要： In this paper, we propose a real-time Internet of Vehicles system based on an automotive headlight. The modulation format is OFDM-64QAM and we successfully reach the data rate of 375Mb/s by utilizing a FPGA as the central host. The transmission distance is 2.5m. We also investigated the performance of the system by calculating BER versus bias current, transmission distance and attenuation at both transmitter and receiver. As far as we know, this is the highest data rate of a real-time visible light communication system based on automotive headlight which can be used in the Internet of Vehicles (IoV).
关键词： Internet of Vehicles (IoV),real-time visible light communication (real-time VLC),automotive headlight,Orthogonal Frequency Division Multiplexing (OFDM)
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Electrical Signatures of Contact Degradation for c-Si Solar Cells
摘要： Time synchronization is an important, yet challenging, problem in underwater sensor networks (UWSNs). This challenge can be attributed to: 1) messaging timestamping; 2) node mobility; and 3) Doppler scale effect. To mitigate these problems, we present an acoustic-based time-synchronization algorithm for UWSN, where we compare several message time-stamping algorithms in addition to different Doppler scale estimators. A synchronization system is based on a bidirectional message exchange between a reference node and a slave one, which has to be synchronized. Therefore, we take as reference the DA-Sync-like protocol (Liu et al., 2014), which takes into account node’s movement by using first-order kinematic equations, which refine Doppler scale factor estimation accuracy, and result in better synchronization performance. In our study, we propose to modify both time-stamping and Doppler scale estimation procedures. Besides simulation, we also perform real tests in controlled underwater communication in a water test tank and a shallow-water test in the Mediterranean Sea.
关键词： timestamp,skew,Doppler scale,orthogonal frequency-division multiplexing (OFDM),time synchronization,underwater sensor network (UWSN),Acoustic communication
更新于2025-09-16 10:30:52