- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Towards Energy Neutral Wireless Communications: Photovoltaic Cells to Connect Remote Areas
摘要： In this work, we have designed, developed and deployed the world’s first optical wireless communication (OWC) system using off-the-shelf lasers and solar photovoltaics. Four bidirectional OWC prototypes have been installed on the Orkney Islands of Scotland at a 30 m link distance for the provision of high-speed internet access to two residential properties. The silicon-made solar panels can harvest power up to 5 W from sunlight and they offer data rates as high as 8 Mb/s. Using additional analogue processing, data rates higher than the existing landline broadband connection are achieved. This breakthrough opens the development path to low cost, self-powered and plug-and-play free-space optical (FSO) systems.
关键词： communication systems,free-space optical communication,light communication,solar energy,optical wireless communications,energy harvesting
更新于2025-09-16 10:30:52
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[IEEE 2019 Photonics North (PN) - Quebec City, QC, Canada (2019.5.21-2019.5.23)] 2019 Photonics North (PN) - Laser ablation generation of gold nanoparticles for highly efficient optical humidity sensor
摘要： Performance of cellular communication systems is typically enhanced by leveraging the three dimensions of system transmission bandwidth, area frequency reuse, i.e. system access point (AP) density, and spectral ef?ciency of employed radio air interface, referred to as the radio access technology (RAT). In particular, re?ned RATs are continuously introduced to compensate for limited spectrum availability and restrictions on system AP densi?cation in cellular communication systems. While the performance of cellular communication systems is maximized by employing a single RAT providing maximal spectral ef?ciency, varying capabilities of user equipment compels the co-deployment of multiple RATs in cellular communication systems and entails fragmenting system radiofrequency resources between co-deployed RATs. Nevertheless, the inef?cient structuring of multi-RAT systems as independently operated collocated single-RAT subsystems results in unbalanced system loading, suboptimal spectrum utilization, and the omission of multiuser diversity as a performance enhancement dimension in multi-RAT systems. The omitted dimension of multiuser diversity is exploited in this paper, through multiple means and techniques, to further enhance the performance of multi-RAT data cellular communication systems. Unifying the architectural structure of multi-RAT systems is proposed to eliminate the redundant duplication of radio access network functions and elements, reduce system deployment costs and operational complexity, improve system scalability, and enable the joint execution of non-radio transmission functions for all co-deployed RATs. By fully exploiting system multiuser diversity, the joint allocation of system radiofrequency resources under autonomous spectrum assignment is shown to substantially enhance the performance of all employed RATs, in addition to the overall performance of multi-RAT systems, without extending any of the three typical performance enhancement dimensions of cellular communication systems.
关键词： spectrum management,radio access technologies,radio access networks,user equipment,Cellular communication systems,multi-radio access technology systems,user access,radio resource allocation
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Ottawa, ON, Canada (2019.7.8-2019.7.12)] 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Numerical Designing of Optical Waveguide by Curvilinear Coordinates
摘要： Performance of cellular communication systems is typically enhanced by leveraging the three dimensions of system transmission bandwidth, area frequency reuse, i.e. system access point (AP) density, and spectral efficiency of employed radio air interface, referred to as the radio access technology (RAT). In particular, refined RATs are continuously introduced to compensate for limited spectrum availability and restrictions on system AP densification in cellular communication systems. While the performance of cellular communication systems is maximized by employing a single RAT providing maximal spectral efficiency, varying capabilities of user equipment compels the co-deployment of multiple RATs in cellular communication systems and entails fragmenting system radiofrequency resources between co-deployed RATs. Nevertheless, the inefficient structuring of multi-RAT systems as independently operated collocated single-RAT subsystems results in unbalanced system loading, suboptimal spectrum utilization, and the omission of multiuser diversity as a performance enhancement dimension in multi-RAT systems. The omitted dimension of multiuser diversity is exploited in this paper, through multiple means and techniques, to further enhance the performance of multi-RAT data cellular communication systems. Unifying the architectural structure of multi-RAT systems is proposed to eliminate the redundant duplication of radio access network functions and elements, reduce system deployment costs and operational complexity, improve system scalability, and enable the joint execution of non-radio transmission functions for all co-deployed RATs. By fully exploiting system multiuser diversity, the joint allocation of system radiofrequency resources under autonomous spectrum assignment is shown to substantially enhance the performance of all employed RATs, in addition to the overall performance of multi-RAT systems, without extending any of the three typical performance enhancement dimensions of cellular communication systems.
关键词： user access,radio resource allocation,multi-radio access technology systems,user equipment,spectrum management,radio access networks,Cellular communication systems,radio access technologies
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) - Superposition Construction of NB-QC-LDPC Codes for optical communication systems
摘要： In this paper, we consider the construction of NB-QC-LDPC code in the framework of superposition for optical communication systems. By maximizing the girth and reducing the number of g-cycles of the base cycle matrix, NB-QC-LDPC codes with good distributions could be constructed. Simulation results show that, with the same implementation cost, the constructed codes could achieve 0.1dB~0.4dB NCG in iterative decoding at the BER of 10^-4 when compared with the recent proposed codes.
关键词： NCG,optical communication systems,girth,superposition,NB-QC-LDPC codes
更新于2025-09-16 10:30:52
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Fiber Amplifiers and Fiber Lasers Based on Stimulated Raman Scattering: A Review
摘要： Nowadays, in fiber optic communications the growing demand in terms of transmission capacity has been fulfilling the entire spectral band of the erbium‐doped fiber amplifiers (EDFAs). This dramatic increase in bandwidth rules out the use of EDFAs, leaving fiber Raman amplifiers (FRAs) as the key devices for future amplification requirements. On the other hand, in the field of high‐power fiber lasers, a very attractive option is provided by fiber Raman lasers (FRLs), due to their high output power, high efficiency and broad gain bandwidth, covering almost the entire near‐infrared region. This paper reviews the challenges, achievements and perspectives of both fiber Raman amplifier and fiber Raman laser. They are enabling technologies for implementation of high‐capacity optical communication systems and for the realization of high power fiber lasers, respectively.
关键词： stimulated raman scattering,optical communication systems,lasers,fiber optics,amplifiers
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) - CdMgTe as an Electron Reflector for MgZnO/CdSeTe/CdTe Solar Cells
摘要： Evolutionary algorithms (EAs) have been shown to be powerful tools for complex optimization problems, which are ubiquitous in both communication and big data analytics. This paper presents a new EA, namely negatively correlated search (NCS), which maintains multiple individual search processes in parallel and models the search behaviors of individual search processes as probability distributions. NCS explicitly promotes negatively correlated search behaviors by encouraging differences among the probability distributions (search behaviors). By this means, individual search processes share information and cooperate with each other to search diverse regions of a search space, which makes NCS a promising method for nonconvex optimization. The co-operation scheme of NCS could also be regarded as a novel diversity preservation scheme that, different from other existing schemes, directly promotes diversity at the level of search behaviors rather than merely trying to maintain diversity among candidate solutions. Empirical studies showed that NCS is competitive to well-established search methods in the sense that NCS achieved the best overall performance on 20 multimodal (nonconvex) continuous optimization problems. The advantages of NCS over state-of-the-art approaches are also demonstrated with a case study on the synthesis of unequally spaced linear antenna arrays.
关键词： Evolutionary algorithms,diversity maintenance,negative correlation,optimization in communication systems
更新于2025-09-16 10:30:52
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Modified downhill simplex method for fast adaption of optical filters in optical communication systems
摘要： The authors propose a control method based on the downhill simplex (Nelder–Mead) method for adaptive optical ?lters used for channel equalisation in optical communication systems. The performance of this method is compared to gradient methods in numerical simulations. The results show that the proposed method can adapt the ?lter to more rapid changes of the transmission channel than the gradient methods.
关键词： adaptive optical filters,channel equalisation,downhill simplex method,optical communication systems,Nelder–Mead method
更新于2025-09-12 10:27:22
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Evolution of degree of polarization of partially coherent beams propagation in slant and horizontal atmospheric turbulence
摘要： In this paper, the analytical expressions for the degree of polarization (DoP) of the electromagnetic Gaussian Schell-model (GSM) beam propagating along a slant path in atmospheric turbulence are obtained. The expressions are used to analyze factors such as the waist radius, amplitude ratio, wavelength, and refractive-index structure constant of the polarization properties of the GSM beam, and we come to some new conclusions. The main results that when the components of the waist radius are equal (rx = ry), there is a waist radius within 2 cm \ rx \ 4 cm that can provide the most concentrated DoP distribution, and the axis point DoP will eventually approach the initial value as the transmission distance increases, implying that it exhibits self-recovering characteristics. In addition, compared to a horizontal path, the DoP distribution of the GSM beam propagating along a slant path is more concentrated, and the propagation distance corresponding to the maximum axis point DoP is longer. Therefore, when the GSM beam propagates along a slant path, the detector can receive information at longer distances. The research results provide a theoretical support for the control of the polarization state of local beam in coherent optical communication systems.
关键词： Coherent optical communication systems,Polarization control,Atmospheric turbulence
更新于2025-09-10 09:29:36
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Traffic Pattern Adaptive Hybrid Electrical and Optical Switching Network for HPC System
摘要： As the performance requirements and scale of high performance computing (HPC) systems grows rapidly, systems with such a large number of computing nodes present significant challenges in network architecture design as their peak performance is increasingly limited by communication rather than computation. Moreover, certain HPC application always shows some specific communication patterns and different topologies has various performances with these patterns. To implement a traffic pattern adaptive HPC system, we propose a topology reconfigurable hybrid network architecture based on optical circuit switching (OCS) which could be adjusted into different classical topologies. And an algorithm of topology calculating and a permutation matrix based optical switch configuration mechanism are proposed to construct network. We discuss network performances with limited OCS switches occupation, and results show that traffic pattern adaptive network improves performance of latency and throughput to a large extent.
关键词： Topology,Optical interconnections,Circuit switching (communication systems)
更新于2025-09-09 09:28:46
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A NEW MINIATURIZED MICROSTRIP BRANCH-LINE COUPLER WITH GOOD HARMONIC SUPPRESSION
摘要： A new miniaturized microstrip branch-line coupler with good harmonic suppression is proposed in this paper. The new structure has two signi?cant advantages, which not only e?ectively reduces the occupied area to 20.4% of the conventional branch-line coupler at 0.96 GHz, but also has high 6th harmonic suppression performance. The measured results indicate that a bandwidth of more than 120 MHz has been achieved while the phase di?erence between S21 and S31 is within 90? ± 1?. The measured bandwidth of |S21| and |S31| within 3 ± 0.3 dB are 145 MHz and 150 MHz, respectively. Furthermore, the measured insertion loss is comparable to that of a conventional branch-line coupler. The new coupler can be easily implemented by using the standard printed-circuit-board etching processes and is very useful for wireless communication systems.
关键词： wireless communication systems,miniaturized microstrip branch-line coupler,harmonic suppression
更新于2025-09-04 15:30:14