最新刊期
卷 ， 期 2 ， 2015
- 摘要：In view of energy efficiency in survival multicast networks with physical layer impairment,this paper proposes a physical layer impairment-based energy-efficient multicast algorithm.This algorithm optimizes the selection of the operating and protecting paths and makes the judgment of physical impairment constraint by modifying the energy consumption cost for operating and protecting the links and minimizes the network energy consumption under the condition of satisfying the physical impairment constraint.Simulation results indicate that this algorithm can save network energy consumption under the condition of satisfying the physical layer impairment constraint.关键词：WDM network;multicast;survivability;physical layer impairment;energy-efficient
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发布时间： - 摘要：This paper proposes a novel Fiber Bragg Grating（FBG）-based two-way transmission tunable Optical Add-Drop Multiplexer（OADM）,describes the principle of its multiplexing/demultiplexing and verifies its structural design and theoretical analysis by using the Optisystem software.Simulation results show that the sidemode suppression ratio of the drop wavelength is about 20 dB,that this device is characteristic of high flexibility and high utilization ratio and two lines in WDM systems are mutually redundant,thus improving the system fault tolerance and expected to be applied in optical networks.关键词：FBG;OADM;two-way transmission
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发布时间： - 摘要：This paper studies by simulation two kinds of modulation formats for modified optical duobinary.It first compares and analyzes the structures of the transmitters that generate these formats,and their code type and spectrum characteristics.Afterwards,it simulates the system transmission performances.The results show that when the residual dispersion is large,the modified type Ⅱ optical duobinary modulation format has better performance.However,within the incident optical power range of-13.2 2.8dBm,the modified type I optical duobinary modulation format has the highest Qvalue and hence the strongest resistance to nonlinear effects compared with the modified typeⅡ optical duobinary and NRZ modulation formats.关键词：modified optical duobinary;modulation format;residual dispersion;nonlinear effect
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发布时间： - 摘要：Most networking of the Ethernet Passive Optical Network（EPON）and Ethernet over Coax（EoC）is currently managed by using independent network management systems.Analyzing the inconveniences of the existing technologies in unified network management,this paper introduces an automatic discovery protocol for EPON and EoC integrated network management equipment and proposes a scheme for realizing EPON-EoC topology automatic discovery in OLT.Test results verify that this scheme is effective in greatly reducing the burden of network management and enables the unified management for EPONEoC networks to become a reality.关键词：EPON;EOC;network topology;automatic discovery;unified network management
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发布时间： - 摘要：Passive Optical Network（PON）technology-based fiber-optic broadband networks are growing rapidly and the traditional PSTN voice services are gradually being replaced by PON-based multi-service bearer.So,fast and efficient implementation of fault diagnosis for PON-based voice service is a problem to service providers.This paper introduces the features and implementation process of the PON-based voice service networking,analyzes the needs for troubleshooting and designs a technical scheme for simulating voice call signaling by using ONU.Test results indicate that this scheme can simulate the operation of user calls,automatically analyze the causes for voice call malfunction,simplify the voice service troubleshooting processes and improve service efficiency.关键词：PON;voice service;simulation;call
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发布时间： - 摘要：As an important technology for ultra-high-rate optical communication systems,advanced modulation technology can effectively improve their capabilities to withstand such adverse effects as chromatic dispersion,polarization mode dispersion and nonlinear effect.Minimum Shift Keying（MSK）is a constant envelope modulation technology with many advantages such as large dispersion tolerance and power concentration.This paper proposes an improved modulation scheme for ultra-high-rate optical communication systems,namely PM-MSK modulation scheme,in which MSK modulation is introduced into the Polarization Multiplexing（PM）system.Theoretical analysis and numerical simulation results show that this scheme has better BER performance than RZ and QPSK schemes.关键词：high-rate optical communication;MSK;polarization multiplexing
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发布时间： - 摘要：To realize the communication between IPv4 internet and IPv6 network by using a translation mechanism,this paper proposes a scheme for implementing NAT64 on data-communication products.On the basis of sufficient analysis of the operating principle of NAT64,this scheme strives to incorporate the existing hardware platform resources and software platform properties,thus reducing the usage of the system resources as much as possible,while ensuring the perfect implementation of the relevant functions.Test results show that the functional requirements of NAT64 are all realized and the operating performances are demonstrated as designed without any adverse effects on either equipment performance or network environment.关键词：transition technology;translation shift;NAT64
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发布时间： - 摘要：With the rapid development of home broadband services in recent years,the traditional Simple Network Management Protocol（SNMP）cannot meet the user demands.TR-069 protocol is proposed as a general framework and protocol for the management and configuration of the terminal equipment of the next generation networks.This paper introduces its framework and working principal,describes the functional design and implementation method of its software modules and gives a testing scheme.It is verified that this scheme implements the designed system functions and is universal and expandable.关键词：TR-069protocol;home gateway;customer premises equipment;auto configuration server
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发布时间： - 摘要：This letter numerically analyzes and experimentally confirms by PCVD process a large effective area single-mode optical fiber.Its effective area is as high as 133μm2 with its attenuation coefficient optimized to 0.183dB/km and its bending loss to 0.45dB/turn at 7.5mm bending radius at 1 550 nm by using a trench structure.Furthermore,it verifies the propagation performances of the 100Gbit/s and 400Gbit/s systems such as BER and Qfactor with dual polarization DFT-S CO-OFDM4QAM/16 QAM modulated signals.The results show that this fiber effectively improves the optimum incident power and the nonlinear effects and extends the propagation distance by 30% and that can effectively optimizes the 400Gbit/s transmission system and has broad prospects of applications in FTTx.关键词：large effective area;400Gbit/s system;low loss;optical fiber;FTTH
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发布时间： - 摘要：By integrating the Plasma Solid-state Outside Deposition（PSOD）,fibre preform fabrication and fibre drawing technologies,we have successfully developed a new preform fabrication process,in which relatively low cost natural quartz sand is used as raw material,plasmas as heat source and drying compressed air as working gas.Using this process,we prepare cladding cylinders that conform to the requirements for fibre production and devise an appropriate technological process for fibre production.This process is simple,needs no dehydration or sintering in the synthetic cylinder process,produces no toxic or harmful gas and so will not pollute the environment.On the basis of our experience in fibre drawing and the special property of nature quartz sand material,we devise the low doping preform deposition technology and the process conditions for high tension drawing.Our fibre products are fully qualified and their attenuation level is low.关键词：natural quartz sand;PSOD;fibre preform;low attenuation fibre
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发布时间： - 摘要：This letter introduces the global research advances of low-loss single-mode optical fibers and analyzes the technical approaches to their realization.On the basis of the study on the physical characteristics of silica glass,it develops the annealing process for silica fibers and reduces their inner-stress,thus lowering their attenuation.The typical attenuation values of the low-loss optical fibers massively manufactured by using our patented technologies with independent IPR at 1 310 nm,1 550 nm and 1 625 nm are 0.320dB/km,0.182dB/km and 0.195dB/km respectively,superior to those specified in the ITU-T and GB/T.关键词：low-loss optical fiber;ultra-low-loss;optical fiber annealing;insulation technology
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发布时间： - 摘要：A novel bend-resistant single-mode photonic crystal fiber in a symmetrical structure is proposed in this paper.The single-mode and bending properties of the fiber are analyzed by using the full-vector finite element method.The fiber is in single-mode operation at 1 550 nm.The bending loss is only 8.73×10-5 dB/turn when the bending radius is 5 mm and it is2.38×10-4dB/turn when the minimum bending radius is 4.5mm.In addition,no matter whether the fiber is bended or not,the mode field area and chromatic dispersion are maintained at about 61μm2 and 11.13ps/（nm·km）respectively at 1 550 nm,well matched with the conventional single-mode fibers.关键词：photonic crystal fiber;low bending-loss;single-mode;FTTH
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发布时间： - 摘要：This paper proposes a compound triangular lattice-based infrared photonic crystal fiber.This fiber uses chalcogenide glass Ge30Sb8Se62 with good transmittance as the substrate material.The lattice consists of circular and square dielectric cylinders,which are horizontally and vertically dislocated in an interphase nested arrangement and every two adjacent cylinders are inclined to each other at 60°.This paper analyzes the photonic bandgap and limit loss characteristics of the fiber in different structures by using the plane wave expansion method and the finite element method and obtains a large bandgap and low-loss photonic crystal fiber at 10.6μm by optimizing the structural parameters of the fiber.关键词：compound triangular lattice;photonic crystal fiber;photonic bandgap;low loss;chalcogenide glass
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发布时间： - 摘要：As strand breakage is a common phenomenon in OPtical fiber composite overhead Ground Wire（OPGW）,this paper presents a strand breakage detecting method by measuring the internal fiber strain with a Brillouin optical time domain reflectometer.In the experiments,it fixes the ends of a section of OPGW on a tensile machine,applies to them a fixed tensile force,gradually increases the number of broken fibers and records the measured fiber strain values.The results show that this method enables over 25% of the cross-sectional area in the strand broken area to be monitored,providing a new idea for monitoring the strand breakage in OPGW.关键词：strand breakage in OPGW;Brillouin frequency shift;fiber strain
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发布时间： - 摘要：In order to generate width/amplitude-adjustable square-wave pulses,this paper realizes independent and continuous adjustment and output of the amplitude and width of square wave pulses of a figure-8dual-pump passively mode-locked fiber laser by simply adjusting the power of the pumps.One pump is used to adjust the width of the output pulses and the other to adjust the amplitude.Simulation results show that this fiber laser can produce amplitude adjustable square wave pulses.This conclusion is helpful to the further study on the mechanism of nanosecond square wave pulse.关键词：fiber laser;passively mode-locked;width/amplitude adjustable;square wave pulse
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发布时间： - 摘要：The position of Fiber Raman Amplifier（FRA）gain peak is determined by pump wavelength and pump lights with different wavelengths produce the maximum gain at different signal wavelengths.In order to obtain the optimum gain characteristic of FRA,this paper builds a multi-pumped FRA system on the basis of a theoretical model of multi-wavelength pumped FRA by using Optisystem software.Then,it studies by system simulation the gain characteristic of the FRA in the fiber-optic communication system,analyzes the effects of transmission range,effective fiber core area,wavelength interval of pump lights,pump light power,number of pumps and other factors on the FRA gain,determines the optimal parameters affecting the FRA gain,and verifies the correctness of the simulation system and the feasibility of the design scheme.关键词：FRA;pump;gain
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发布时间： - 摘要：In view of the extensive applications of electronic gears in sports contests and the development of Taekwondo electronic gears,fiber-optic sensor-based Sanda electronic protective gear is proposed.On the basis of the principle and characteristics of the existing fiber-optic microbend sensors,an appropriate microbend modulator and sending/receiving system of this gear is designed.Fibers are bended to different degrees under the action of certain external impact force,thus different voltage values obtained,which are used to judge the sizes of the impact force.The experimental test results show that in a certain range,the impact force is approximately linear with the voltage values,realizing the automatic evaluation and scoring for Sanda competitions.关键词：electronic protective gear;fiber-optic microbend sensor;impact force;voltage value
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发布时间： - 摘要：To improve the bandwidth efficiency,power demand of communications and anti-jamming capability of signal transmission in channels,we mainly study Digital Pulse Interval Modulation（DPIM）mode applied in wireless laser communication systems and compare by simulation and analysis the power,bandwidth,unit signaling rate and error performance of OOK,PPM,DPPM and DPIM mode.In addition,we design a FPGA-centered DPIM system on the basis of the theoretical analysis of DPIM.The results show that this system is stable in performance and can achieve high modulation rate.关键词：laser communication;DPIM;modulation;FPGA
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发布时间： - 摘要：In view of such problems as imbalance,instability and inaccuracy of structural division existing in the operation of the current Weighted Clustering Algorithms（WCA）in ultraviolet communication networking,this paper proposes an improved WCA.This algorithm is based on the rational number of cell division determined by an energy loss model and calculates the communication connection time with the relative inter-node mobility considered in the power change factors.The simulation and analysis show that the proposed algorithm improves the network stability,enables the selection of the central node to be more balanced,thus further improving the performance of ultraviolet communication networks.关键词：optical communication;ultraviolet communication;networking method;weighted clustering algorithm
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发布时间： - 摘要：This paper proposes a PSK external modulation-based laser communication system.Using a 637 nm all-solid-state laser as a light source and FPGA demoboard as the modem hardware to control the acousto-optic modulator,this system applies the modulated signals to the laser and,using aphotomultiplier tube as a laser receiver via atmospheric channel transmission,improves the traditional PSK demodulation,eliminates phase ambiguity and sets up a complete experiment platform for laser communication systems,realizing a laser communication system with the serial communication rate of 115.2kbit/s and bit error rate of lower than 10-8.关键词：PSK;phase ambiguity;laser communication;FPGA
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发布时间： - 摘要：In respect of reducing node energy consumption in Wireless Sensor Networks（WSN）,this paper proposes an energyefficient network coding model,presents the relevant network coding strategy and energy consumption mode and establishes a new node energy-efficient algorithm by using the network coding multi-path routing technology.In addition,it experimentally compares this algorithm with the relevant multi-path routing protocol algorithms taking BER as the reference basis.Simulation results show that the proposed algorithm bring about marked improvements in terms of energy consumption efficiency,network lifetime extension and data packet transport.关键词：network coding;energy-efficient;data packet;BER
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发布时间： - 摘要：In the study on CoMP-JT resource allocation,it is found that the traditional ZF beam-forming precoding technology may lower the average utilization ratio of antenna transmission power under the condition of per-antenna power constraint.In order to further improve the system throughput,this paper proposes a joint precoding and power allocation algorithm,which improves the utilization ratio of antenna transmission power by using aprecoding iterative calculation method.Simulation results show that this algorithm performs much better than the traditional ZF precoding algorithm.关键词：joint transmission;precoding;per-antenna power constraint
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发布时间： - 摘要：As the ultraviolet light signal at the receiver end of ultraviolet communication systems with LED as the light source is weak,this paper proposes a set of complete optimized design scheme for photomultiplier-based ultraviolet voice-receiving system.This system consists of I/V conversion,magnification,filtering and shaping circuits,which are all designed and realized using modularized design ideas.Simulation and experimental test results indicate that when the light source 1.6mW LED emits voice signals at the rate of 4.8kbit/s,the system can correctly recover distinct and complete voice signals within a radius of10 mand in quasi line of sight.关键词：ultraviolet communication;PMT;lowpass filter;shaping circuit
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