最新刊期
卷 ， 期 2 ， 2014
- 摘要：Optical buffering in the core nodes of Optical Burst Switching（OBS）networks can effectively resolve contentions in burst data packet.This paper first analyzes the deficiencies of the conventional optical buffer structures and then proposes an improved master-slave optical buffer structure and a weighted priority-based balancing scheduling algorithm to overcome the deficiencies of the conventional fair scheduling algorithm and priority scheduling algorithm.Comparison results show that this algorithm demonstrates certain superiorities in terms of system waiting time,average waiting time and space utilization.关键词：optical burst switching;burst data packet;contention;optical buffering
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发布时间： - 摘要：Intrachannel Four-Wave Mixing（IFWM）is one of the major nonlinearities affecting the signal transmission quality of high-bit-rate long-range dispersion management quasi-linear fiber-optic transmission systems.In this paper,a numerical calculation model is derived for describing the transmission process of quasi-linear fiber-optic transmission systems by adopting the Split-Step Fourier Method（SSFM）and a nonlinear compensation scheme for an economical and effective dispersion management in combination with pulse pre-broadening.After that,the intensity of the ghost pulse at the output end is just a quarter of that before the pre-broadening.Calculation results indicate that this scheme effectively suppresses IFWM,obtains ideal compensation effects and has a certain guiding significance for the design of high-rate fiber-optic communication systems in the future.关键词：dispersion management;quasi-linear transmission;IFWM;pulse pre-broadening
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发布时间： - 摘要：Openflow is one of the most key core technologies in the existing Software Defined Network（SDN）systems.In view of the possible resource shortage in the existing SDN technology,this paper proposes a resource-reuse-based Openflow flow table storage optimization scheme involving the operation of the Openflow flow table in SDN.On the basis of the existing Openflow v1.3.1,it defines a new table structure,proposes an algorithm for computing the correlation degree of the flow table and designs a new procedure for its updating.The experimental results show that this scheme optimizes the information storage of the table entries,efficiently utilizes the available hardware resource,thereby storing more table entries under the same hardware conditions.关键词：SDN;Openflow protocol;resource-reuse;flow table;priority
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发布时间： - 摘要：Taking into consideration of various influencing factors,it is of major significance to have an exact and computationally efficient evaluation algorithm for the variance of Four-Wave Mixing（FWM）noise to the optimal design of DWDM systems. On the basis of neglect of inter-channel crosstalk,this paper first obtains the pulse transmission law by using the dynamic splitstep Fourier algorithm and then on this basis,obtains the channel overlap functions that determine the efficiency of FWM.Calculation results of examples show that FWM efficiency is to a certain extent related to the pulse variations in the course of propagation:when group-velocity dispersion coefficient is relatively small,the normalized characteristic width is relatively large and when the peak-power of the incident pulse is relatively large,the correlation degree is large,and that when the chirping coefficient is positive and large and the propagation rate is relatively high,the effects of pulse variations with the propagation distance on FWM efficiency cannot be neglected.关键词：DWDM;dynamic split-step Fourier algorithm;FWM efficiency;overlap function
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发布时间： - 摘要：As the operators’ management networks,Data Communication Networks（DCN）carry large amount of traffic information concerning Operation,Administration and Maintenance（OAM）.Therefore,it is necessary for the operators to safely, efficiently and reliably manage and monitor such networks.From the perspective of Network Management（NM）design,this paper uses topology calculation and display as well as the topological link auto-discovery functions to implement the smart management of DCN topology and offer user-friendly graphical interfaces,thus satisfying their need for the real-time monitoring and effective management of DCN.关键词：NM;DCN management;topology calculation and display;topological link auto-discovery
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发布时间： - 摘要：<正>2013年中国电信100Gbit/s WDM/OTN国干集采结果于近日正式揭晓。烽火通信凭借优异的传输性能和强大的系统平台,在激烈的竞争中脱颖而出,以综合排名前二的优势获得北京-石家庄-郑州-武汉段、京津济徐合-北京天津段、广南贵渝成-汉渝成段100Gbit/s DWDM系统建设工程三个标段,市场份额超过30%,位居第二。为适应4G、宽带中国和云计算等业务的应用,从容应对后续业务的大幅增长,中国电信面临着带宽升级
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发布时间： - 摘要：<正>2014年3月13日,烽火通信与印度尼西亚运营商PT TELEKOMUNIKASI INDONESIA（TELKOM,印尼电信公司）在汉隆重举行了共建联合创新中心（JIC）签约仪式。此次签约,将进一步支撑印尼电信与烽火通信在家庭智能应用等前沿技术研究领域的战略合作,助力印尼电信在TIMES（通信、信息、传媒、寓教于乐及服务）领域保持领先优势。据悉:这是继烽火通信和马来西亚电信签订吉隆坡联合实验室之后的又一重大活动,对双方实现优势互
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发布时间： - 摘要：This paper realizes optical delay and dispersion compensation by using the optical field relationship in micro-ring resonators and controls the phase shift changes in the micro-ring by using the Kerr effect.Furthermore,it gives the optimized parameters of the designed device,which can reach a dispersion compensation value of greater than-1 200ps/nm when the jittering is smaller than±8ps and at the same time,the compensation bandwidth of all channels are higher than 20GHz,satisfying the requirements of DWDM systems.The entire structure is small in power consumption（less than 1.2mW）,fast in response,fully light controllable and small in volume and easy for integration.关键词：dispersion-compensation;micro-ring resonator;optical Kerr effect
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发布时间： - 摘要：In view of the current requirements for ceaselessly increasing the transmission rate of optical communications,this paper designs and realizes a Quad Small Form-factor Pluggable Plus（QSFP+）optical transceiver module,with single-channel transmission rate up to 10Gbit/s and the total quad data rate of 40Gbit/s.It uses an 850nm Vertical-Cavity Surface-Emitting Laser（VCSEL）array as the light-emitting device and a high-speed PIN Photoelectric Detector（PD）array as a light receiving device.Compared with the traditional design,this model lowers the designing complexity and the overall cost.The simulation and test results show that the channel crosstalk is lower than-42dB,the receiver sensitivity better than-11dBm and the overall performance indexes satisfy the requirements of IEEE 802.3ba standard.关键词：quad parallel optical transceiver module;VCSEL;QSFP+
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发布时间： - 摘要：As an important component for photoelectric conversion,optical transceiver module plays a vital role in the field of high-rate data communications.By studying and applying VCSEL and PIN array technologies and integrated driver chips,this paper develops an optical transceiver module in strict compliance with the CXP Multi-Source Agreement（CXP MSA）,called CXP optical transceiver module,In the tests of its sample,it obtains the key parameters,such as eye pattern and receiver sensitivity.The test results indicate that this module fully complies with the requirements of its technical indexes and is applicable to short-range high-rate data communication systems,having major significance to increasing the transmission rate of data transmission systems and promoting the development of 100Gbit/s optical communication systems.关键词：CXP optical transceiver module;high-rate data communication;VCSEL array;PIN array
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发布时间： - 摘要：This paper focuses on the inability to obtain the phase-frequency characteristics when testing the frequency response of photoelectric detecting elements by using the step response method.It sets up an equivalent circuit model that provides the same parameters as the actual devices by using the Multisim software and proposes a method for the simultaneous frequency response measurement of the amplitude-frequency and phase-frequency characteristics on the basis of the relationship between the phase difference and the time difference of the phase-frequency characteristics.The measurement results of amplitude-frequency characteristics are consistent with those by using the traditional step response method.The phase-frequency characteristics of photoelectric diodes have major influences on the design of high-speed receiving systems.关键词：Photodiode;frequency response;Multisim simulation
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发布时间： - 摘要：Hybrid fiber amplifiers are widely used in DWDM systems.In view of the defects of current hybrid fiber amplifiers, this paper proposes an EDFA/RFA-based hybrid fiber amplifier,in which the gain variations are regulated on a unified control platform without a built-in VOA and the RFA and EDFA gains can be mutually compensated and so their gain tilts,ensuring the flatness of the gains.Experimental results show that this hybrid fiber amplifier is characteristic of low noise,high gain and flattened gain bandwidth.关键词：hybrid fiber amplifier;gain;gain tilt;mutual compensation
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发布时间： - 摘要：For still wider applications of Fiber Bragg Grating（FBG）in practical projects,this paper presents a FPGA-based high-speed demodulation algorithm and the implementation of its key technologies.It designs a signal demodulation hardware platform using the FPGA technology,implemets the accurate positioning of the FBG reflective spectral peak values using the low-complexity L-M fitting algorithm and increases the demodulation processing speed by simplifying the L-M algorithm.The test results show that this algorithm has good stability and repeatability and meets the requirements for high-speed,real-time and highly accurate measurement.关键词：FBG;wavelength demodulation;L-M algorithm;high-speed demodulation;FPGA
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发布时间： - 摘要：In order to satisfy the requirements of distributed fiber Bragg grating sensor systems and ultra-high-rate all-optical communication systems,this paper designs and implements a novel hybrid Erbium-and Thulium-Doped Fiber（TDF）super-fluorescent ultra-wideband light source.In the experiments,it uses 980nm and 1 480nm laser diodes to pump the Er-Doped Fiber（EDF）,generating C+L band light.Then it uses 30%of this light to optically pump the TDF,producing S-band fluorescence light.Finally,it couples the remaining 70%of C + L-band light with the S-band fluorescent light,resulting in an ultra-wideband S+C+L light source.The total power of this light source is 36mW（15.6dBm）,with a bandwidth of 1 4601 610nm. The test results of this light source show that its bandwidth,power and other performance indexes satisfy the requirements for the applications of distributed fiber grating sensor systems and all-optical communication systems.关键词：fiber optics;S+C+L band;EDF;TDF;optical circulator
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发布时间： - 摘要：For the study of the dispersion and coupling characteristics of hybrid dual-core Photonic Crystal Fibers（PCF）,we propose a new type of hybrid dual-core PCF based on two light guiding mechanisms:total internal reflection and photonic bandgap effects.On the basis of the coupled-mode theory,we analyze its effective index,coupling length and dispersion characteristics by using the finite element method and the plane wave expansion method,and study the directional couplers and optical wavelength selectors.The simulation results show that the proposed PCF has large negative dispersion and fine coupling properties.These results have significant reference values for the theoretical research on the coupling and sensing properties of dualcore PCF and the practical applications of the relevant devices.关键词：fiber optics;hybrid light guiding;coupling length;dispersion characteristics;optical device
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发布时间： - 摘要：For multi-channel dispersion compensation in DWDM systems,this paper first analyzes the sampled fiber grating by using the transfer matrix method and on this basis carries out simulation experiments by regulating the linear chirping coefficients.The simulation results indicate that in the multi-channel dispersion compensation,the reflective spectra of the chirped sampled fiber grating are uniform and all the reflectivities are above 90%;that the delay spectrum is consistent and the minimum delay jitter is smaller than 40ps;and that the dispersion diagram is also uniform and can compensate both the positive and negative dispersion,and in the simulation,the dispersion value does not exceed 500ps/nm.关键词：sampled fiber grating;linear chirp;dispersion compensation;reflective spectrum
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发布时间： - 摘要：The introduction of Device-to-Device（D2D）technology into the LTE systems in a non-orthogonal way of reusing resources may bring about interferences,i.e.mutual interferences between the cellular users and the D2Dusers.In the D2Dsystems,cross-layer resource optimization can cope with instantaneous channel worsening arising from the interferences for the cellular users,thus improving their average spectral efficiency and increasing the system capacity.This thesis studies a link-adaptive cross-layer optimization scheme for the D2Dsystem,which combines the adaptive modulation and coding technology in the physical layer with the auto repeat request technology in the data link layer,aiming at lowering the interferences arising from the introduction of the D2Dtechnology.Simulation results indicate that in a single cell scenario with 4cellular users and 4 pair of D2Dusers,the total capacity of the D2Dcommunication system is increased by about 5% when the link-adaptive crosslayer optimization scheme is adopted.关键词：D2Dtechnology;cross-layer optimization;link-adaptive technology
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发布时间： - 摘要：In 3GPP,the Carrier Aggregation（CA）technology is introduced in the Long Term Evolution-Advanced（LTE-A） systems,which allows the User Equipment（UE）to invoke different bandwidths simultaneously.At the same time,the Physical Uplink Share Channel（PUSCH）allocation is not limited to transmitting only one continuous spectrum resource any more. Therefore,carrier aggregation-based PUSCH allocation becomes a new research topic.However,the existing schemes are only the reuse of the previous technologies and cannot maximize the utilization of recourses.On the basis of these schemes,this paper proposes a scheme where the utilization of PUSCH resources is maximized in the carrier aggregation scenario.The system simulation results show that the improved scheme can achieve the desired purpose.关键词：carrier aggregation;multi-carrier;PUSCH;PDCCH
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发布时间： - 摘要：Wireless channels are complicated with time-variant and fading characteristics.As the Adaptive Modulation and Coding（AMC）technology can make communication systems adaptive to these channels,it has become a key technology to the 3GPP Long Term Evolution（LTE）system.This paper presents an AMC implementation scheme for the LTE system and simulates and tests its performances.The simulation results indicate that this scheme effectively improves the system throughput.关键词：LTE;AMC;wireless channel;system throughput
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发布时间： - 摘要：This paper introduces various technologies for the reduction of the Peak-to-Average Power Ratio（PAPR）of Orthogonal Frequency Division Multiplexing（OFDM）systems,modifies the conventional Partial Transmit Sequence（PTS）technology and proposes a partial-correlation-PTS method.The fundamental idea of this method is that after the original modulated frequency domain signals are divided into several data blocks,every other data block than the first one does cross-correlation calculation with the first data block and then continue to handle partial-correlation data subblocks in accordance with the conventional PTS method.At the receiver end,the multiplied rotation phase of each data subblock except the first one is decided according to the positive or negative property of the cross-correlation value of that subblock with the first data subblock.Thus the original signals can be recovered without transmitting sideband information.The effectiveness of the partial-correlation-PTS method is verified by the simulation results.关键词：OFDM;PAPR;PTS;partial-correlation
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发布时间： - 摘要：In order to meet the requirements of modern wireless communications,this paper calculates the cut-off wavelength and loss coefficients of inverted trapezoidal single-ridge waveguide by programming the Finite Element Method（FEM）.With the mutual coupling between slots considered,it calculates the active admittance of inverted trapezoidal ridge waveguide slot array by using the traveling-wave approximation method and extracts the normalized active admittance of the slots by HFSS and finally designs a novel 26-element single-ridge waveguide traveling-wave slot array in the X band.Simulation results show that the side-lobe level is lower than-25dB and the Voltage Standing Wave Ratio（VSWR）throughout the band is sound.关键词：mutual coupling;inverted trapezoidal single-ridge waveguide;active admittance;traveling-wave slot array
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