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- 摘要
- 关键词
- 实验方案
- 产品
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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) - Uniform-Multilevel Amplitude Regeneration using a Polarization-orthogonal Continuous-wave-light-assisted Nonlinear-optical Loop Mirror
摘要： We experimentally investigate a multilevel amplitude regeneration of NRZ-PAM4 signals using a novel continuous-wave-light-assisted polarization-orthogonal nonlinear-optical loop mirror (PC-NOLM) subsystem, which creates the uniform noise-suppression behavior on multiple amplitude levels.
关键词： Signal regeneration,PAM,NOLM,Sagnac effect,Fiber optics communications
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) - Dynamic Neural Network Enabled 50 Gb/s PAM-4 IM/DD Transmissions Based on 10G-Class Optical Devices
摘要： A dynamic neural network based equalization scheme is experimentally demonstrated for 50 Gb/s PAM-4 signal transmissions based on 10G-class optical devices. More than 2.5 dB power penalty improvement is achieved compare to the MLSE.
关键词： 50 Gb/s PAM-4,Dynamic neural network,10G-class optical devices
更新于2025-09-16 10:30:52
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[IEEE 2019 International Topical Meeting on Microwave Photonics (MWP) - Ottawa, ON, Canada (2019.10.7-2019.10.10)] 2019 International Topical Meeting on Microwave Photonics (MWP) - Mode-Division Multiplexed PAM-4 Signal Transmission in a Silicon Photonic Chip
摘要： Emerging 5G mobile networks and cloud computing applications are driving the demand for an ever-increasing capacity for short-reach optical communications. To meet this demand, mode-division multiplexing (MDM) is being employed to scale up the bandwidth capacity by leveraging the spatial modes of an optical waveguide for transmitting multiple optical signals. On the other hand, the use of PAM-4 can also increase the transmission bandwidth since PAM-4 offers four amplitude levels in a symbol and thus its bit rate is twice as high as OOK at a same baud rate. Therefore, on-chip MDM with PAM-4 is an approach to enhance the transmission capacity in a photonic integrated circuit. In this paper, we report a photonic integrated four-channel MDM circuit that is implemented on a silicon platform with a small size and low channel crosstalk. By using the MDM circuit, a 80 Gbit/s mode-division multiplexed PAM-4 signal transmission is experimentally demonstrated. The advantage of the approach is that high data capacity on-chip communications is enabled by the photonic integrated MDM circuit with a small footprint. The MDM circuit can be employed in a radio over fiber (RoF) system to increase the data transmission capacity of the RoF link.
关键词： PAM-4,silicon photonics,mode-division multiplexing
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE/MTT-S International Microwave Symposium - IMS 2019 - Boston, MA, USA (2019.6.2-2019.6.7)] 2019 IEEE MTT-S International Microwave Symposium (IMS) - 30Gb/s 60.2mW 151GHz CMOS Transmitter/Receiver with Digitally Pre-Distorted Current Mode PAM-4 Modulator for Plastic waveguide and Contactless Communications
摘要： 151 GHz CMOS transmitter and receiver are presented for ultra-short distance (~1 mm) contactless connection and plastic waveguide communications. To continue to scale the communication bandwidth, the 4-level pulse amplitude modulation (PAM-4) is utilized by implementing a current-mode PAM-4 modulator in the transmitter. The transmitter and receiver suffer non-linear characteristics and create amplitude distortions on PAM-4 signaling. A digital pre-distortion circuit is integrated in the PAM-4 modulator to correct such system non-idealities. 151 GHz antennas are realized on FR4HR substrate and used as air-to-air/chip-to-waveguide couplers. On top of contactless connection and plastic ribbon waveguide, plastic-embedded PCB channels are introduced by exploiting copper-coated slots on PCB and plastic ribbons to communicate through PCB substrates. The transmitter and receiver are fabricated in 28-nm CMOS process. The demonstrated system consumes 60.2 mW under 1.2 V supply while transferring 30 Gb/s of PAM-4 data, achieving 2.01 pJ/bit energy efficiency.
关键词： 151 GHz transmitter/receiver,PAM-4 modulation,contactless communication,plastic-embedded PCB,digital pre-distortion,plastic waveguide
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Artificial Neural Network Equalizers for PAM-4 using DML-on-Silicon
摘要： Nonlinear equalizers (NLEs) based on artificial neural networks (ANNs) are studied for short-reach 4-level pulse amplitude modulation (PAM-4) transmissions utilizing directly-modulated membrane lasers fabricated on silicon substrates (DMLs-on-Si). Using 28-GBaud signals over 2-km of single-mode fiber (SMF), we compare two ANN-NLEs with a previously developed reduced-complexity Volterra-NLE (VNLE).
关键词： Optical Transmission,DML-on-Silicon,Nonlinear Equalizers,PAM-4,Artificial Neural Network
更新于2025-09-11 14:15:04
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Comparison of Optical OFDM and M-PAM for LED-Based Communication Systems
摘要： Light-emitting diode (LED)-based communications, such as visible light communications (VLC) and infrared (IR) communications, are candidate techniques to provide short-range and high-speed data transmission. In this paper, M-ary pulse amplitude modulation (M-PAM), used as a high bandwidth efficiency scheme, is compared with three well-known optical orthogonal frequency division multiplexing (OFDM) schemes. Considering the bandwidth limit and constrained peak transmitted power characteristics of LEDs, a bit loading algorithm and single-tap equalizer with an optimized modulation index are used for the optical OFDM schemes tested. To reduce the inter-symbol interference caused by the bandlimited channel, an optimized pulse shape and a minimum mean squared error (MMSE) equalizer are applied to the M-PAM system. From numerical results, M-PAM can provide a substantially higher data rate than OFDM for bandlimited channels. When the channel bandwidth is ample compared with the symbol rate, optical OFDM outperforms M-PAM.
关键词： pulse shaping,infrared communications,M-PAM,OFDM,bit loading,visible light communications,MMSE equalizer,optical wireless communications
更新于2025-09-11 14:15:04
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Towards 50 Gb/s in High-Speed PON: Optimization of Modulation Formats Using Pre-Chirping
摘要： High-Speed (HS) Passive Optical Network (PON) alternatives with single-wavelength capacity higher than 10 Gb/s, such as 25 and 50 Gb/s, are currently under investigation, development and standardization. Modulation formats based on intensity modulation and direct detection (IM-DD) have been preferred to implement next generation HS-PON due to their advantages in terms of complexity and cost. Among them, conventional Binary Pulse Amplitude Modulation (PAM-2) format, as well as Quaternary PAM (PAM-4) and Electrical Duo-Binary (EDB), have been emerged as the most widely employed. In previous works, we have shown that any of these formats is feasible for the transmission of 50 Gb/s using currently available 25 Gb/s technology when operating in C-band of single mode fibre (SMF) for typical PON distances (i.e., 20 km). In this contribution, we introduce the use of pre-chirping technique in order to overcome this reach limitation. We compare the achievable performance of PAM-2, PAM-4 and EDB under demanding bandlimited and dispersive conditions on the transmission of 50 Gb/s using adaptive equalization, with and without pre-chirping. By means of simulations, we demonstrate that using pre-chirping enables the operation of PAM-2 and PAM-4 on the transmission of 50 Gb/s through 20-km of SMF in O- and C-band, respectively, using currently available technology.
关键词： PAM,NRZ,pre-chirping,PON networks,50 Gb/s,EDB
更新于2025-09-11 14:15:04
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Approach in companding-quantisation-inspired PAM constellation design
摘要： In this study, a very simple but successful method for designing the pulse-amplitude modulation (PAM) constellations with non-equiprobable symbols and not equally spaced amplitudes is presented. The method, inspired by companding quantisation, introduces a constellation design function having a feature that maps the non-uniformly distributed constellations points into uniform ones. In particular, two classes of piecewise-linear constellation design function having two segments are provided. In PAM constellation designed by the proposed method, the set of constellation points is divided into two uniform subsets. Each of these subsets is characterised by a certain probability of constellation points and by a constant distance between adjacent points. For this model of PAM constellation, the formulas that enable the elegant assessment of the signal energy and the symbol error probability are derived. Results obtained analytically and verified through simulations show that, in terms of the symbol error probability, the proposed PAM constellations outperforms conventional uniform PAM constellation as well as the other models of piecewise-uniform PAM constellations.
关键词： PAM constellations,non-equiprobable symbols,symbol error probability,piecewise-linear constellation design function,companding quantisation
更新于2025-09-10 09:29:36
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Four-PAM Modulation of Ambient FM Backscattering for Spectrally Efficient Low-Power Applications
摘要： Ambient backscatter uses radio frequency signals available in the environment (e.g., radio broadcasting, television, or mobile telephony) to transmit data effectively leading to significant energy and cost efficiency increase. This paper presents a novel wireless tag, which for the first time utilizes 4-pulse amplitude modulation technique to modulate the ambient backscattered FM signals in order to send data to a nearby low-cost software defined radio reader. The tag is based on an RF front-end that uses a single transistor controlled by an ultralow-power microcontroller. The microcontroller includes an analog-to-digital converter for sensing and a digital-to-analog converter for RF front-end control. A proof-of-concept prototype is demonstrated in an indoor environment with the low bit rate of 345 b/s and power consumption 27 μW. It operated using a real FM station at 34.5 km away and the tag-to-reader distance was tested at 1 m. The value of energy spent in this modulator was 78.2 nJ/bit at 345 b/s and 27.7 nJ/bit at 10.2 kb/s.
关键词： Internet-of-Things (IoT),backscatter communication,Ambient backscattering,software-defined radio (SDR),pulse amplitude modulation (PAM),FM modulation,radio frequency identification (RFID) sensors
更新于2025-09-10 09:29:36
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Probabilistically Shaped 8-PAM Suitable for Data Centers Communication
摘要： We study non-uniform 8-PAM signaling schemes, based on Maxwell-Boltzmann and exponential source distributions, as candidates suitable for data centers’ communications. We evaluate mutual information of these schemes against corresponding uniform 8-PAM scheme, for different parameters of source distributions. The properly chosen variable parameters for different SNR-regions allows us to closely approach Shannon limit, and to significantly outperform the corresponding uniform counterpart. We demonstrate that LPDC-coded 8-PAM with exponential distribution outperforms the LDPC-coded 8-PAM with uniform distribution of the same achievable information rate by 1.8 dB, and this improvement is comparable to that obtained from mutual information calculations.
关键词： 8-PAM,distribution matching,probabilistic shaping,LDPC coding,exponential distribution
更新于2025-09-09 09:28:46