最新刊期
卷 ， 期 2 ， 2019
- 摘要：This paper designs and studies a bidirectional chaotic secure communication system, A theoretical model and system architecture for bidirectional chaos synchronization are proposed. We also demonstrate the feasibility and safety of its communications. By utilizing the symmetry of both systems in communication, the robustness of the chaotic synchronization to dispersion and nonlinear effects is improved. Finally, the communication between the two sides anti-interception secure communication can be achieved through simulation, which proves the chaotic laser system is coupled to each other.关键词：chaos synchronization;secure communication;anti-interception
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发布时间： - 摘要：In Software-Defined Flexible Bandwidth Optical Networks（SD-FBONs）, the energy-efficiency problems have to be solved in order to meet the requirements of the green and energy-saving optical networks. In this paper, considering the programmable characteristics of optical switching nodes, the service architecture of SD-FBONs is flexibly operated by the network center controller and application layer controller based on the extended OpenFlow protocol. An Energy-Optimized Mixed-Line-Rate Dedicated Protection Approach（EO-MLR-DPA） is proposed to reduce the energy consumption, and the Traditional Dedicated Protection Approach（T-DPA） is introduced for comparison in SD-FBONs. The simulation results show that, compared with T-DPA, the proposed EO-MLR-DPA can effectively reduce the power consumption and optimize the configuration of the optical transponder and optical regenerator under different line rates and modulation formats in SD-FBONs.关键词：software-defined networks;flexible bandwidth optical networks;energy efficiency
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发布时间： - 摘要：To solve the issues of the long development cycle and poor flexibility of industrial Passive Optical Metwork（PON）, we proposed a scheme composed of Field Programmable Gate Array（FPGA） with integrated high-speed serial transceivers instead of external physical layer chip. The hierarchical design model and data frame structure are improved and the character length of burst synchronization can be reconfigured online according to the burst synchronization performance of the optical line terminal transceiver. The results of board level verification show that the system can complete the data frame reception and burst mode transmission at the rate of 3.125 Gbit/s, with advantages of high compatibility and low complexity.关键词：PON;optical network unit;serial transceiver;burst data frame;FPGA
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发布时间： - 摘要：In order to improve the spectrum and power efficiency in Visible Light Communication（VLC） and location system, we propose an Asymmetrically Clipped and DC-biased Optical-Orthogonal Frequency Division Multiplexing（ADO-OFDM） technique, which combines the advantages of Asymmetrically Clipped Optical-OFDM（ACO-OFDM） and DC-biased Optical-OFDM（DCO-OFDM） with higher spectrum efficiency than ACO-OFDM and higher power efficiency than DCO-OFDM. We also apply a differential correction location algorithm, which has higher positioning accuracy than the traditional three-side location algorithm.关键词：VLC;integrated system of communication and locations;ADO-OFDM;differential correction location algorithm
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发布时间： - 摘要：Aiming at the design and mapping of service function chain in Network Function Virtualization（NFV）, a NFV mapping algorithm based on Node Selection strategy（NS-NFV） is proposed. Considering the virtual node dependency in the design of service function chain, NS-NFV determines the mapping order of virtual nodes according to the node resource degree. It also selects the optimal mapping node for the virtual node according to the importance of the physical node, and completes the design and mapping of service function chain in a coupling manner. Simulation results show that NS-NFV can effectively reduce the backtracking steps and running time. In addition, the request acceptance rate can be improved significantly.关键词：NFV;service function chain;node selection strategy;node resource degree
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发布时间： - 摘要：In the power system, when the cable is subjected to strong impulse current, it will work in the temperature field higher than 10% of the conductor’s maximum operating temperature. The long-term high-temperature aging condition has a great negative effect on the optical fiber in the optical unit of Optical Fiber Composite Low-Voltage Cable（OPLC）, which seriously affects the safe operation of the entire power grid. Aiming at the above problems, in order to study the mechanical properties of single-mode fiber before and after heating, the damage degree of high temperature aging to optical fiber is analyzed. In this paper, the mechanical properties of single-mode fiber, such as breaking strength, elongation at break and stripping force of coatings, are tested at different temperatures and aging periods by emulating the temperature field of OPLC conductors 10% higher than that of polyvinyl chloride insulated conductors. Based on the test data, the change trend of mechanical properties of optical fiber before and after aging under this temperature field is studied by using the statistical method of linear fitting. The results show that the stress corrosion sensitivity parameters of optical fiber in OPLC are more sensitive to heat than the coating peeling force characteristics. With the increase of aging time, the difference between the coating stripping force and the stress corrosion sensitivity parameters is larger and the heat resistance is worse. Based on the test results of mechanical properties, the suggestion of adding heat-resistant layer of optical unit is proposed in this paper.关键词：optical fiber;OPLC;aging;mechanical properties
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发布时间： - 摘要：Due to the advantages of small volume and simple structure,the cladding mode of the in-fiber interference sensor is used widely. Therefore, the investigation of the sensing mechanism and improvement of the measurement performance are the key factors to study this sensor. By using the finite difference beam propagation method, the interference spectrum of the sensors with removing partial of cladding and bending are simulated in this paper. The order of dominant cladding mode is obtained by comparing dispersion equation and spatial frequency spectrum after Fourier transform. The results show that, compared with normal sensor, the orders and numbers of cladding modes both increase. Meanwhile, with the increasing of bending radius within limits, the cladding modes order increase.关键词：in-fiber interference;cladding mode;spatial frequency spectrum
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发布时间： - 摘要：In order to fabricate high-efficient flat broadband mid-infrared supercontinuum fiber, a microstructured fiber based on As2Se3 as background material is proposed. By using nonlinear Schrodinger equation, the effects of fiber structure parameters on dispersion, loss and nonlinear characteristics are simulated, and the optimized structure is designed. The optimal structural parameters are selected to achieve high nonlinearity with flattened full normal dispersion. The mechanism of ultrashort pulse broadening is analyzed by using this structure optical fiber. The effects of fiber length, pump center wavelength, peak power and pump width on the generation of supercontinuum are studied, and the output of the flat mid-infrared supercontinuum is realized by this fiber. By building experimental platform, the transmission and output spectrum of femtosecond laser pulses in As2Se3 microstructured fibers are measured by selecting the optimized fiber length and pump parameters. The experimental results show that high efficiency flat broadband mid-infrared supercontinuum with wavelength broadening of 3～6 μm can be generated. This continuous spectrum can be used in the fields of material detection, biochemistry, food detection and environmental analysis.关键词：microstructured optical fiber;supercontinuum;mid-infrared wave;high-nonlinear;femtosecond pulse laser
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发布时间： - 摘要：In order to solve the problem of serious powder drop of water-blocking yarn during the production process of totally dry optical cable, a new manufacturing process of water-blocking yarn was developed in this paper. The prepolymer of high water absorbable performance resin is synthesized first. The resin with high water absorbility is then polymerized on the matrix yarn by coating and curing process. Finally, the water resistance resin and the base yarn are integrated into one. Testing result indicates that the performance of the water blocking yarn can completely meet the requirements of the communication industry standard and the technical specifications of the cable manufacturers. The process test of the optical fiber cable production shows that the water blocking yarn produced by the above technology can be applied to manufacture totally dry optical cable, and can solve the problems of powder drop and dust pollution.关键词：totally dry optical cable;absorbent resin;water blocking yarn;sodium acrylate
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发布时间： - 摘要：In order to meet the requirement of high speed data transmission at 400 Gbit/s, a new microstrip structure which can reduce the crosstalk of high frequency signal is presented in this paper. Based on the analysis of the electric field distribution by using High Frequency Simulation Software（HFSS）to build and analyze 3 D electromagnetic model, the simulation result shows that the crosstalk of the device with this new microstrip structure is less than-30 dB within the frequency range of 0～ 60 GHz, which meets the requirement of 400 Gbit/s optical device.关键词：high frequency circuit;microwave structure;HFSS;crosstalk
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发布时间： - 摘要：In order to improve the accuracy and efficiency of the thermal stress analysis of the planar optical waveguide by the finite element method, an improved plane strain model is presented. In this improved plane strain model, the thermal expansion coefficient of materials is described in orthogonal anisotropic way, and the material’s thermal expansion coefficient in the direction perpendicular to the propagation of the waveguide remains the actual material’s thermal expansion coefficient. However, the thermal expansion coefficient of material along the direction of propagation of the waveguide is changed appropriately to maintain deformation coordination. With the modified material model, the thermal stress of the planar optical waveguide is calculated by the ordinary plane strain model. The calculation results show that the maximum error of the stress obtained by the improved plane strain model is only 0.4% compared with the generalized plane strain model, and the calculation time is reduced to 12.6% of the generalized plane strain model. Compared with the ordinary plane strain model, the calculation precision of the improved plane strain model is greatly improved with almost same calculation time.关键词：planar optical waveguide;thermal stress;improved plane strain model;finite element
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发布时间： - 摘要：In view of the growing requirements of bandwidth, transmission speed and capacity, a kind of 50 Gbit/s PAM4 QSFP28 optical transceiver module is proposed, which can meet the demands of 40 km transmission. The PAM4 technology is used to increase the transmission capacity in each single wavelength. At the receiver side, the key component of the photo-detector is APD, which can increase the ability of identifying weak signal, and meet the requirement of 40 km transmission in 50 GE. The circuit of reception unit is optimized to obtain a better transmission effect. The result indicates that the transceiver can work steadily, meet the demands of 40 km transmission in 50 GE.关键词：PAM4;QSFP28;50 GE;APD;40km
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发布时间： - 摘要：For 5 G wireless prequel network, the 6 and 10 Gbit/s optical modules of the original 4 G base station equipment can not meet the demand. A 25 Gbit/s 1 310 nm Receiver Optical Subassembly（ROSA） device is designed for the emerging 25 Gbit/s optical module, which is packaged with low-cost and small-size coaxial structure. In this paper, we introduce the characteristics of core materials used in the device including the 25 Gbit/s 1 310 nm self-made PIN photodiode and the Transistor Outline（TO）. The packaging form of the device and the production process of the product are also introduced. Then the sample is fabricated. The responsiveness, loss-back, sensitivity and bandwidth of the device are tested. The results show that the performance of the product can fully meet the requirements of commercial grade and can be commercially used on a large scale with qualified yield.关键词：5G prequel network;25 Gbit/s 1310nm ROSA;coaxial encapsulation
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发布时间： - 摘要：For the content offloading scenario in the fog computing network architecture, this paper proposes a traffic offloading strategy based on content popularity and social relationships. The proposed strategy first combines the distribution of content popularity. Then it determines content relay users based on the social trust and social reciprocity model between users. Finally, Device-to-Device（D2 D） technology is introduced to achieve content sharing between users, thereby effectively reducing offloading delay of the task requesting users and the load of the fog computing network. The model of queuing theory is used to analyze the energy consumption and delay performance of the proposed strategy. Simulation results show that the proposed strategy can effectively reduce energy consumption and delay, while improving the user experience and system performance.关键词：fog computing;D2D;popularity;social trust;social reciprocity;queuing model
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发布时间： - 摘要：A key area of research for wireless transmission is underwater communications, where acoustic signals are currently the best candidates for underwater communications. Orthogonal Frequency Division Multiplexing（OFDM）technique facilitates high data rate transmission over Underwater Acoustic（UWA） channels. In this paper, the UWA trust, in a communication channel is proposed based on the Fractional Fourier Transform（FRFT） of OFDM system. According to various conditions with the traditional OFDM systems, the system performance is deeply investigated. The conditions include the number of subcarriers, the modulation scheme and the Doppler frequency. Finally, the results show that although the calculation order of FRFT is the same as that of Fast Fourier Transform（FFT）, the performance of FRFT-based OFDM systems is better than traditional OFDM systems in all multipath scenarios,which meets the requirement that the underwater acoustic channel has low system complexity and low power consumption.关键词：UWA communication;complexity;FRFT;Doppler frequency;OFDM
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