最新刊期
卷 ， 期 3 ， 2010
- 摘要：With the extensive commercial applications of Optical Transport Networks（OTN）,ROADM technology is gradually becoming one of its important node technologies.This paper analyzes three main ROADM technologies,gives suggestions for its selections for different network applications and proposes a hybrid ROADM equipment pattern,which combines the advantages of two ROADM technologies that are based respectively on wavelength blockers and wavelength selective switches,and has still better applicability.关键词：ROADM;wavelength selective switch;wavelength blocker;composite structure
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发布时间： - 摘要：All-optical format converter is an indispensable part of the future optical networks as it can enhance their availability and flexibility.In this paper,we propose a novel all-optical format conversion from On-Off-Keying（OOK） to Optical Frequency-Shift-Keying（OFSK） on the basis of the Transient Cross-Phase Modulation（T-XPM） effect in a Semiconductor Optical Amplifier（SOA） assisted by an optical Bandpass Filter（BPF）.This scheme is simple in structure and easy to the implemented.We experimentally realized an all-optical 40 Gbit/s OOK-OFSK format conversion and invested the conversion properties.关键词：all-optical format converter;T-XPM;OFSK;OOK;SOA
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- 122
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发布时间： - 摘要：This paper designs and realizes an embedded-database-based WDM-PON system software,which provides the graph network management and various character terminal users with management interfaces and implement the management,monitoring and assignment of various telecommunication services.The use of an embedded database helps enhance its performances,especially its reliability and real-time performance and shorten its development cycle.关键词：system software;embedded database;high reliability;WDM-PON;OLT
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- 64
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发布时间： - 摘要：This paper presents the considerations of designing a SystemC-based reusable test bench for communication systems,which is divided into 4 layers,i.e.user end layer,configuration and management layer,Bus Function Module（BFM） layer and Design Under Test（DUT） layer.It introduces the modes of communication and interfaces for each layer and focuses on the design method for reusable core modules such as user end module,algorithm modules,port modules,stimulus modules,BFM modules and scoreboard modules.A reusable test bench can be fast and efficiently built by using this method.关键词：test bench;reusability;controlled randomized stimulus;BFM
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- 46
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发布时间： - 摘要：Compared with the traditional optical networks,Optical Packet Switching（OPS） networks are characteristic of such outstanding advantages as high speed,large throughput,low latency and high efficiency in carrying IP services.As the most promising optical backbone network to support the development of the next-generation Internet,The compatibility with support to OPS and TCP/IP networks is a subject worth of in-depth study.Taking the Optical Burst Switching（OBS） network as a model,this paper studies the Transmission Control Protocol（TCP） performances in the OPS switching network.关键词：OPS;OBS;TCP transmission performance
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- 81
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发布时间： - 摘要：The single-channel transmission rate of the global telecom backbone networks is advancing to 40 Gbit/s or even to 160 Gbit/s and as the main transmission medium,the loss and dispersion of optical fibers impede the extension of communication distance and capacity.In order to fit in with the demand for the development of the existing communication networks,Polarization Mode Dispersion（PMD） adaptive technology is developed in the optical fiber technology on the basis of the hardware descriptive language in connection with the current FPGA technology,ensuring the stability of the PMD adaptive compensation technology.关键词：transmission rate;optical fiber;PMD;FPGA;adaptive compensation
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- 75
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发布时间： - 摘要：Short-haul high-speed information transmissions can be realized by applying the Orthogonal-Frequency-Division-Multiplexing（OFDM） technology to Multimode Fiber（MMF） transmission links.The mode dispersion of MMF is calculated by using the optical angular spectrum method and a theoretical model of the directly modulated MMF transmission is built on the basis of the OFDM principle and such typical system performance parameters as transmission rate and BER are numerically analyzed.The results show that the transmission distance of the standard OC-768（40 Gbit/s） signals in SONET can be as long as over 2.5 km when the receiver BER is limited to 10-3.关键词：optical communication;multimode fiber;OFDM;angular spectrum
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- 84
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发布时间： - 摘要：In the Network Management System（NMS） of communication networks,disaster tolerance technologies are usually used to ensure high system reliability and data synchronization is one of them.To implement highly efficient data synchronization,it is necessary to optimize the characteristics of the data to be synchronized.Taking the master-slave synchronization functions of FiberHome OTNM2000 transmission network management system as an example,this article introduces the principles of several data comparison algorithms and their applications in the master-slave synchronizationverifies process,which is of some reference values to the optimization of similar data synchronization or remote data backup technologies.关键词：dada comparison algorithm;data synchronization;disaster tolerance technology
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发布时间： - 摘要：Multi-service differentiation is the basis of differentiated performance guaranteeing and network security monitoring.Real-time service differentiation can be realized on the basis of the service peak rate.Differentiation methods for static and dynamic services are respectively proposed in accordance with the correlation among boundary value of the rate based on service and the link load rates,by which multi-services can be dynamically differentiated as real-time and non-real-time ones in the state of real-time links.The feasibility and simplicity of this method are verified on the basis of C++ programming simulation.关键词：service differentiation;flow peak rate;multi-service networks
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发布时间： - 摘要：On account of the current social background and evolutionary tendency that the convergence of telecommunication,broadcast/television and computer networks is pushed forward,this paper presents a fiber-optic access solution appropriate for triple-play-based communities and analyzes the principle of its design and realizable functions.Simulation results show that this solution is appropriate for the triple-play access networks.关键词：triple play;fiber-optic access;solution;Opent simulation
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发布时间： - 摘要：With the development of information technology and multi-network service convergence,remote monitoring is gradually moving away from the traditional closed-loop mode and forming a relatively independent platform with enormous potential of growth that can carry multiple services,including voice,video and data.In this paper,in line with the actual needs of electric power enterprises for on-site scheduling,the Wireless Video Monitoring（WVM） technology is applied to integrate the traditional industrial TV monitoring with the wireless network video technology closely and a wireless video monitoring system for power dispatch is designed.关键词：WVM;on-site scheduling;video codec technology
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- 25
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发布时间： - 摘要：The paper first introduces the basic steps in the design of fiber-optic loose tubes for ribbon optical cables and briefly describes their main technological points.Then it explains the key points in the design by quantitative analysis and explains the issues for attention in their production on the basis of the production practice and puts forward suggestions for the selection and use of the fiber jellies as the important parts of the tubes.Finally,it experimentally verifies the effects of the jelly on the tubes and of the twist pitches on the cable performances and gives the curve diagrams of tensile tests in different twist pitches.关键词：fiber-optic ribbon cable;loose tube;fiber jelly;pitch
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- 180
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发布时间： - 摘要：In the paper,the control algorithms for 45°-0°-45° phase retardation polarization controllers is discussed,the errors introduced to phase retardation is analyzed and the correlations between the azimuth angle error and ellipticity angle error of the output polarization state and the latency error are observed by simulation.The results show that the latency error has less effect on ellipticity angle error than that on azimuth angle error.Effects of the latency error that are caused by the incident optical wavelength error on the output polarization state precision is also analyzed.Simulation results show that the 45°-0°-45° phase retardation polarization controller is wavelength sensitive.关键词：polarization controller;phase retardation;error analysis;wavelength
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- 108
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发布时间： - 摘要：In view of the current situation of distributed optical fiber sensing technology,two kinds of optical temperature and strain sensing technologies,based respectively on coherent optical time-domain reflection and double-pulse Brillouin optical time-domain reflection,are introduced in this paper.They have such advantages as high measurement precision and high spatial resolution and can be widely used in the fields of national defense and scientific research.Their systematic schemes and measurement principles are analyzed in detail,their key techniques and innovations pointed out and the trend of development of the distributed optical fiber sensing technology discussed.关键词：distributed optical fiber sensing;temperature;strain;Rayleigh scattering;Brillouin scattering
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- 508
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发布时间： - 摘要：A novel structure of liquid-crystal-based tunable photonic crystal resonators is presented in this paper.Simulation and calculation are conducted by using FDTD algorithm-based Fullwave software,obtaining the resonant frequencies and quality factors in the resonators in different refractive indexes of the liquid crystal.The results show that 6 resonant frequencies are produced in the tubing with a tunable range of 31.937 nm,4 of which have good lasing qualities and the highest quality factor is about 60 000 and the lowest one about 2 000.It can be seen that this kind of resonators are characteristic of large tuning range and high quality factors,thus applicable in tunable lasers.关键词：photonic crystal;liquid crystal;resonator;tuning
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- 181
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发布时间： - 摘要：A double-rectangular photonic crystal structure is presented.Its energy band structure is first calculated by using the Plane Wave Expansion Method（PWM） and its parameters are optimized,resulting in larger photonic bandgap.The analytical results show that when monocrystal silicon is used as the material of the dielectric cylinder,the lattice constant ratio of the rectangular lattice is in a range of 0.350.45,the ratio between the side length of square dielectric cylinder and the major axis of the rectangular lattice is in a range of 0.450.50.The resulted full bandgap can reach 0.500.58 and the complete bandgap rate is close to 39%,which is of great significance for the development of photonic crystal devices with excellent performance.关键词：optoelectronics;photonic crystal;plane wave method;rectangular lattice;complete bandgap
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- 93
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发布时间： -
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- 摘要：The aperiodic auto-correlation and cross-correlation of LA sequences have a zero correlation zone near the origin.Thus,a quasi-synchronous coherent time-spreading OCDMA system can be realized by applying the LA sequences to the OCDMA system.The beat noise and multiple-access interferences in the system can be cancelled as long as the time delay between the users is controlled within the range of synchronous errors.A quasi-synchronous coherent time-spreading 1 Gbit/s OCDMA system with 16 users and a transmission range of 20 km is simulated,the result of which indicates that the LA code is applicable to quasi-synchronous coherent time-spreading OCDMA systems.关键词：optical communication;OCDMA;LA code;aperiodic cross-correlation
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发布时间： - 摘要：A Radio-Over-Fiber（ROF） communication system is given and analyzed,in which Four-Wave Mixing（FWM） is used to generate sideband and transmit baseband signals.Two pairs of optical carrier suppression sidebands are generated in its central station,one transmits the downlink signals and the other carries the baseband signals and transmits the uplink signals at the base station.The system spectrum and Bit Error Ratio（BER） curve obtained by simulation indicate that when the baseband signals are coupled,the energy penalty of the downlink signals remains unchanged,while the baseband and uplink signals have better dispersion resistance.关键词：ROF;four-wave mixing;baseband signal;carrier suppression;down-link
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发布时间： - 摘要：On the basis of the tailbiting convolutional code for Long Term Evolution（LTE） systems,this paper chooses an optimal Viterbi decoding algorithm for the TD-LTE test system after comparing multiple Viterbi algorithms by simulation and realizes it in the TMS320C64x DSP.It presents a number of specific strategies and techniques for software optimization and greatly simplifies the addition comparison selection butterfly computations.The running results of the decoding program in CCS3.3 verify the feasibility and effectiveness of this algorithm and the optimization strategies and techniques.关键词：LTE;Viterbi decoding;soft-decision;DSP realization
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发布时间： - 摘要：A new family of two-dimensional（2-D） optical orthogonal address code is constructed by using two orthogonal linear polarization lights on the basis of the synchronous modified prime code for synchronous optical CDMA systems.Its choice principle is determined by analyzing the auto-correlation and cross-correlation of 2-D codes,on the basis of which a 2-D optical encoder appropriate for synchronous OCDMA systems is designed.Simulation results prove that the 2-D optical orthogonal address code has still better receiver properties compared with that for the one-dimensional synchronous OCDMA system and resolves the problem of nonlinear addition of power that may occur in practical encoder usage.关键词：synchronous OCDMA;synchronous modified prime codes;fiber optic delay;polarization
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