最新刊期
卷 ， 期 5 ， 2012
- 摘要：As networks are constantly upgraded to high speed and high capacity,it has become a problem demanding prompt solution to adaptively avoid physical layer impairment in the routing process.To this solution,the perception and retention of the impairment information is the key.This paper sets up an information characterization table for the distributed Physical Layer Impairment-aware Database（PLID） by analyzing the physical-layer impairment parameters,makes reference to the traffic engineering database standard protocol and expands the OSPF-TE protocol in it so as to establish and update the PLID.It is found that when the control overheads for different modes of update for the database are compared,threshold-based update is more suitable as it can satisfy the requirements of different QoS for the quality of channel transmissions at different wavelengths.关键词：WDM;PLID;database update;LSA
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发布时间： - 摘要：In line with the requirements of high-rate optical communication systems for Optical Signal-to-Noise-Ratio（OSNR）,this paper proposes a Super-FEC scheme based on an irregular Low-Density Parity-Check（LDPC） long code.This scheme uses the BCH code in different systems as the outer code and the LDPC code as the concatenated way of the inner code.In view of the needs of the systems for different bit rates,it designs different concatenated structural forms.In the simulation,the net coding gains of these Super-FEC schemes are in the range of 6.187.63 dB,which are higher than those of the traditional schemes.关键词：high-rate optical communication;Super-FEC;BCH;LDPC;concatenated code
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- 200
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发布时间： - 摘要：In order to satisfy the demand for high bandwidth in the LTE era and achieve the sharing of transmission bandwidths for dynamic data services to the maximum limit,this paper presents a scheme for the network management software to realize the group service management on the basis of analyzing the application scenarios of layer 2 and layer 3 group services and describing and comparing the comprehensive performances of MSMP from the background management to the Graphical User Interface（GUI）.This scheme can well create group services in the network management by using the bridging technology in the intermediate node and ensure the reliability in reporting services to GUI and downloading them to the devices,having significant practical application values.关键词：layer 2 and layer 3 group service;MSMP;bridging technology
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发布时间： - 摘要：With the wide applications of the Multi-Service Access Platform（MSAP） system,its maintenance has become increasingly important,especially in respect of the upgrade of the remote devices.This article presents a method for the automatic online upgrading of all nodes in the MSAP system.The upgrading starts from its Digit cross-connect Manager Unit（DMU） and the DMU downloads the upgrading program from the server via the standard FTP and implements data validation.Every node in the MSAP system delivers the program to the subordinate devices through the store-and-forward mechanism.DMU can monitor the entire upgrading process via the feedback mechanism and ensure the success of the upgrading.The results indicate that the devices in the MSAP system can be effectively,steadily and automatically upgraded online,the users can monitor the upgrading process of the devices through DMU serial port and this method is applicable to any hierarchical systems.关键词：MSAP;online upgrade;automatic upgrade
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发布时间： - 摘要：With the explosive growth of communication services,40 Gbit/s WDM systems have been commercially applied in large scales in the existing backbone networks.This paper analyzes the related issues in the construction of 40 Gbit/s systems,including fiber selection,coding options,10 Gbit/s service solutions for 40 Gbit/s WDM systems,Optical Line Protection（OLP）,client-side solutions.关键词：40 Gbit/s WDM systems;dispersion;OLP;client-side
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- 94
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发布时间： - 摘要：In order to satisfy the demands for different high bandwidth services,a hybrid access network for simultaneous transmission of wired and wireless signals is presented.In the downstream links,wireless signals are transmitted in the phase modulation format,wired signals re-modulated in the intensity modulation format on optical carriers,and different demodulation schemes employed for modulation and reception at the ONU.In the upstream links,wired base-band signals are remodulated by using the carrier reuse technology and transmitted to the OLT,thus simplifying the system device configuration.The system reliability and effectiveness are verified by using the optical software Optisystem 7.0.The simulation results show that fairly good eye diagrams can be obtained at the user end after the wireless link signals and wired BB signals are modulated and transmitted,indicating that they can be accurately received and the upstream BB signals can also be accurately received at the OLT by using the carrier reuse technology.关键词：optical communication;WDM-PON;orthogonal modulation;interleaver
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发布时间： - 摘要：In view of the stability of and inter-service interference effects on WDM-ROF-PON systems for multi-service transmission,a WDM-ROF-PON system for simultaneous transmission of two kinds of wireless services is designed.In the experiment,tests are performed on four ROF channels in downlinks,the results of which show that the system can simultaneously transmit 60 GHz 2.5 Gbit/s millimeter-wave signals and 5 GHz 155 Mbit/s DPSK signals for 20 km.In each channel,the power penalty in intermediate or lower frequency transmission is 0.42.8 dB and in the millimeter-wave transmission 1.53.2 dB and in millimeter-wave transmission only,the receiver sensitivity is improved by 0.62 dB.These results show that the signal transmission performances for both services in every channel are good,the system is stable and the millimeter-wave services are subject to minor interferences from lower frequency services.关键词：ROF;WDM;multi-service system;optical millimeter wave;PON
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- 209
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发布时间： - 摘要：Adiabatic Soliton Compression（ASC） is an important means for obtaining ultra-short pulses.In this paper,a novel ASC scheme based on Nonlinear Optical Loop Mirror（NOLM） is proposed,which is made up of a 3 km-long linear Dispersion Decreasing Fiber（DDF） assisted by 7 dB/km distributed Raman gain.In this scheme,10 ps pulses are compressed to 195.3 fs,with a compression factor of 51.2 and the pedestal energy of only 11.61%,which indicate that this scheme can not only increase the compression factor,but also effectively suppresses the pedestal of compressed pulses.关键词：ASC;dispersion decreasing fiber;NOLM;distributed Raman amplification
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- 58
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发布时间： - 摘要：Automatic logo recognition is one of the key elements of vehicle information collection in an intelligent transportation system（ITS）.Considering the abundant marginal information about the vehicle logo,this paper applies the characteristic values of the Histograms of Oriented Gradients（HOG） and implements the fast vehicle logo detection and recognition with the help of Support Vector Machine（SVM）.Furthermore,it proposes an improved HOG,which achieves evident results in terms of the accuracy of vehicle logo detection and recognition.Large amounts of experimental data and applications in ITS show that this method is fairly robust and practically useful.关键词：HOG;SVM;vehicle logo recognition;vehicle logo location
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发布时间： - 摘要：The coating strip-force of tight-buffered fiber is an important index that embodies product quality,but it is not explicitly defined in the relevant standards due to the lack of testing data accumulation in earlier stage.In this paper,some experimental study is carried out on such a coating strip force.It is found in the tests that as their coatings are fairly thick,"jam-up" effect is likely to occur and the strip force judgment is significantly affected by this jam-up effect in addition to the movement length and speed of the stripping tool and the total strip length.These conclusions provide an important basis for scientifically defining the effective scope of the strip force and can be used as the foundation for the research work in next stage.关键词：optical fiber;tight-buffered fiber;coating strip force;indoor fiber cable
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- 107
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发布时间： - 摘要：The reliability of optical fibers is the key to ensuring the service life of optical communication networks,which is determined by both their strength distributions and their fatigue behaviors.In this paper,the effects of such factors as screening intensity,stress corrosion susceptibility parameters and load level on fiber reliability are analyzed by using the fiber strength distribution data and the Monte Carlo method.The analytical results indicate that while the increase of the screening intensity can improve the screened fiber strength distribution,it may result in the obvious decrease of parts of the screened fiber strength.In line with the power law theory-based fiber fatigue behavior model,the theoretical lifetime of fibers can be increased with the increase of the stress corrosion susceptibility parameters and the decrease of static load level on the fibers.关键词：optical fiber;reliability;strength distribution;power law;stress corrosion
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- 206
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发布时间： - 摘要：In order to realize in a simple way Photonic Integrated Circuits（PIC） and Optoelectronic Integrated Circuits（OEIC） for active and passive optical devices with different band-gap structures in the same wafer,this paper acquires a band-gap blue-shift in InP/InGaAsP structure material by using plasma-induced disordering Quantum-Well Intermixing（QWI） and Rapid Thermal Annealing（RTA） technologies,in which the band-gap offset can be flexibly controlled by depositing SiO2 gray-scale masks with different duty ratios on the material surface.In the experiment,five kinds of bandgap wavelengths are obtained on the substrate in this method,among which the maximum offset is 75 nm.These results show that this technology is an effective means for realizing PIC and OEIC and has a broad prospect of applications in multi-bandgap structures.关键词：photonic integration;QWI;multi-quantum well
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- 57
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发布时间： - 摘要：This paper investigates the use of a double stage regeneration structure to suppress the timing jitter arising from self-phase modulation-based all-optical regenerators,analyzes the timing jitter suppression performances of A-A,B-B and C-C types of double stage regenerators and performs simulation by using the distributed Fourier transformation algorithm.Theoretical analysis and numerical simulation results indicate that type C-C has the best performance in timing jitter suppression,followed by type B-B,while type A-A aggravates the timing jitter of the regenerated signals.The differences in performance are mainly caused by the effects of the pulse amplitude variation output of the first stage regenerator on the timing jitter of the second stage regenerator.关键词：fiber-optic communication;all-optical regeneration;self-phase modulation;timing jitter;transfer function
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- 38
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发布时间： - 摘要：With the sustained growth of internet traffic,100 Gbit/s Ethernet has gradually become commercially available..Its client optical module is a 100 Gbit/s CFP optical transceiver module.This paper introduces the relevant standard of this module and describes the design scheme of a kind of module,which consists of rate conversion unit,transmitting unit,receiving unit and control unit.Tests are performed in the light of IEEE Std.802.3ba and the results indicate that the average launch power in each lane is 1.47 dBm and the receiver sensitivity is-9.5 dBm.This means that the performances of this module entirely conform to the relevant standards and can be applied in 100 Gbit/s Ethernet.关键词：100 Gbit/s Ethernet;100 Gbit/s CFP optical module;CFP MSA;IEEE 802.3ba standard
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- 276
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发布时间： - 摘要：With the in-depth research on the Microwave Photonic Filter（MPF）,the design methods and MPF performances have been enormously improved,but little reports about the development of some typical filters with given parameters have been made.On the basis of the in-depth research on the digital filters and MPF structures,the detailed design process of the bandpass Butterworth MPF using the design method for digital filters is given,obtaining the zeroes and poles of the required transfer functions.The filter transfer functions are implemented by using fiber ring-assisted cascading Mach-Zehnder Interferometer（MZI） cascading and the structural parameters of various cascaded MZI such as coupling coefficients,arm length differences and the ring length are determined by the calculation of the zeros and poles of the transfer function.They are verified in simulation and the results are basically in agreement with the design requirements.Furthermore,the effects of different structural parameters on MPF are investigated.关键词：MPF;MZI;optical fiber ring;transfer function
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发布时间： - 摘要：In order to reduce the Full Width at Half Maximum（FWHM） of slot-type cavity filters,we numerically simulate the structures of the Metal-Insulator-Metal（MIM） waveguide-based single slot-and cascaded slot-type cavity filters by using the Finite-Difference Time-Domain（FDTD） method and analyze their transmission spectra by using the coupled mode theory.The simulation results show that the FWHM of the transmission spectrum of the cascaded slot-type cavity filters can be effectively suppressed to be only about 30%40% of that of the single slot-type cavity filters.关键词：SPPs;coupled resonance;wavelength filtering;integrated optics
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发布时间： - 摘要：In order to alleviate traffic jams,enhance road capacity,reduce traffic accidents,lower energy consumption and lessen environmental pollution,it is helpful to build an Intelligent Transportation System（ITS） based on a Wireless Sensor Network（WSN） and the ZigBee protocol.The wireless network is constructed by deploying sensor nodes,which collect such physical parameters and environmental information such as vehicle speed,traffic flow,ambient temperature,road noise and vibration so as to achieve the aim of vehicle supervision.This system is simulated by using OPNET Modeler and the network simulation results in different topologies,traffic flows and node failures are discussed and the network performances evaluated,providing a reliable and quantitative basis and reference for the network planning and system construction.关键词：ITS;WSN;ZigBee protocol
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- 184
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发布时间： - 摘要：In connection with the node position estimation and routing control in Ad Hoc networks,this paper proposes an Optimized Link State Routing（OLSR） protocol-based integrated protocol,i.e.OLSR-Positioning（OLSR-P） protocol,which can implement routing and positioning simultaneously.This improved protocol effectively integrates routing overheads and positioning procedures and modifies the data packet structure so as to implements positioning by using the routing overheads of the original protocol.The simulation results show that the OLSR-P protocol can realize routing and positioning simultaneously and effectively control the routing overhead.关键词：Ad Hoc network;OLSR;positioning;OLSR-P
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发布时间： - 摘要：Cyclic Prefix（CP） plays a role in preventing inter-symbol interferences in TD-LTE systems and only when the relevant CP type is determined at the receiver end,can the accurate FFT decoding window be fixed.This paper presents the CP-based relevant algorithm and energy difference algorithm and,using CP as the replication feature of the symbol end data,estimates the CP type on the basis of the correlation coefficient ratio and the energy difference ratio between different CP lengths.Considering the algorithm complexity and the simplicity and easiness of DSP realization,it further improves this algorithm and proposes a partial CP sequence-based set-related energy difference algorithm.Simulation results and the algorithm principle demonstrate its applicability and low complexity.关键词：TD-LTE;cyclic prefix;energy difference;correlation
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发布时间： - 摘要：This paper introduces three kinds of scheduling algorithms commonly used in wireless correspondence.In order to improve the spectrum utilization rate,it proposes a QoS-based Proportional Fair（PF） scheduling algorithm on the basis of comparing the influences of these three algorithms on the system performances.This algorithm incorporates the advantages of the other scheduling algorithms.In the experiment,it allocates the users with different QoS parameters and the users with different allocations have different throughputs.Furthermore,the system gives priority to the needs of the optimal users.This algorithm improves the maximum throughput of the system,ensures the fairness of user scheduling,provides the users with different services and satisfies the different needs of the users.关键词：LTE;proportional fair;QoS
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发布时间： - 摘要：On the basis of shift sequence and the interleaving technique,a novel method for the construction of No-Hit-Zone（NHZ） frequency hopping sequence sets suitable for frequency hopping communication systems is proposed in this paper.The resultant parameters of the NHZ frequency hopping sequence sets are optimal in respect to the Peng-Fan-Lee bounds and they can be flexibly set.Different from the existing ones,these NHZ sequence sets have periods twice as much as the number of frequency points,applicable to still more occasions.关键词：frequency hopping sequence;NHZ;Hamming correlation;interleaving technique
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