We propose a polarization mode dispersion (PMD) compensation scheme for wavelength-division-multiplexing (WDM) system, in which two WDM channels share one PMD compensator at the receiver site. The effect of different ...
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ISBN:
(纸本)0819464481
We propose a polarization mode dispersion (PMD) compensation scheme for wavelength-division-multiplexing (WDM) system, in which two WDM channels share one PMD compensator at the receiver site. The effect of different modulation formats on multi-stage PMD compensators is studied and compared by numerical simulations in 40-Gb/s WDM optical fiber communication system. The degree of polarization (DOP) of single state of polarization (SOP) optical signal is used as the feedback signal in PMD compensators. The particleswarmoptimization (PSO) algorithm is used as the searching algorithm in WDM systems. The compensated DOP values of return-to-zero (RZ) format and nonreturn-to-zero (NRZ) format by multi-stage PMD compensators have been increased distinctly compared to the corresponding cases without compensation. It is shown that the PSO algorithm is implemented successfully in adaptive multi-stage PMD compensation in a 40-Gb/s optical WDM system. The compensated eye diagrams for the two channels by multi-stage PMD compensators indicate that the three-stage PMD compensator which eliminates the influence of second-order PMD completely in WDM system takes the best efficiency in the multi-stage PMD compensators for RZ format and NRZ format.
We adopt the worst channel equalization (WCE) scheme to compensate polarization mode dispersion (PMD) in wavelength-division-multiplexing (WDM) systems. The degree of polarization (DOP) of single state of polarization...
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ISBN:
(纸本)0819464481
We adopt the worst channel equalization (WCE) scheme to compensate polarization mode dispersion (PMD) in wavelength-division-multiplexing (WDM) systems. The degree of polarization (DOP) of single state of polarization (SOP) optical signal is used as the feedback signal of the PMD compensators, and the particleswarmoptimization (PSO) algorithm is used as the searching algorithm. Simulation results show that the DOP of RZ format of the worst-performance channels after compensation is greatly improved, and the PSO algorithm is successfully experienced into adaptive multi-stage PMD compensators in a 40-Gb/s optical WDM communication system. The WCE scheme is an effective way for PMD compensation in WDM system.
In this paper, a fuzzy controller with dual controller structure is proposed for solving the contradiction between steady performance and dynamic performance of usual fuzzy controllers. The structure of the obtained c...
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ISBN:
(纸本)1424400600
In this paper, a fuzzy controller with dual controller structure is proposed for solving the contradiction between steady performance and dynamic performance of usual fuzzy controllers. The structure of the obtained controller is simple and its algorithm is convenient, it has good robust and dynamic performance, and can effectively eliminate steady state deviations. For avoiding complex adjustment of parameters as asked for in the design of fuzzy controllers, and attain optimal control properties, a particleswarmoptimization (PSO) algorithm has been made use of to optimize the parameters of a fuzzy controller during design. Numerical simulations based on typical controlled objects demonstrate the effectiveness and the adaptability of the algorithm, as well as the superiority of the designed controller.
When transferring the geometric constraint equation group into the optimization model, we need a method to jump out of the local beat solution so that we can find a global best solution. Considering the speed and glob...
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ISBN:
(纸本)1424403316
When transferring the geometric constraint equation group into the optimization model, we need a method to jump out of the local beat solution so that we can find a global best solution. Considering the speed and global capability, we adopt compound particle group optimizationalgorithm. particle swarm optimization algorithm is a kind of evolution computation technology based on group intelligence. In all the evolution computations heuristic function should be included to control its one's own characteristic. These parameters are usually correlated with the specific problem and are defined by the users. Suitable parameter choice needs user abundant experience and correct judgment on the information offered by the problem. More important thing is that these heuristic parameters will influence the convergence characteristic of the algorithm. Because of this even experienced users may choose the not appropriate parameter and then make the problem unable to get effective solution. It needs to carry on some research on these parameters more and more. Here we choose the control parameters as an optimization question in the particleswarmalgorithm. Thus heuristic function in the PSO can be controlled by the ordinal genetic algorithm and we form the composite particle swarm optimization algorithm. And we use this algorithm into the geometric constraint solving successfully.
In this paper, a fuzzy controller with dual controller structure is proposed for solving the contradiction between steady performance and dynamic performance of usual fuzzy controllers. The structure of the obtained c...
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In this paper, a fuzzy controller with dual controller structure is proposed for solving the contradiction between steady performance and dynamic performance of usual fuzzy controllers. The structure of the obtained controller is simple and its algorithm is convenient, it has good robust and dynamic performance, and can effectively eliminate steady state deviations. For avoiding complex adjustment of parameters as asked for in the design of fuzzy controllers, and attain optimal control properties, a particleswarmoptimization (PSO) algorithm has been made use of to optimize the parameters of a fuzzy controller during *** simulations based on typical controlled objects demonstrate the effectiveness and the adaptability of the algorithm, as well as the superiority of the designed controller.
＜正＞In order to improve the stability and dependability of the Direct Torque Control （DTC）system in low speed state of asynchronous dynamo.a kind of reformative particleswarmoptimization（PSO）algorithm. which o...
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＜正＞In order to improve the stability and dependability of the Direct Torque Control （DTC）system in low speed state of asynchronous dynamo.a kind of reformative particleswarmoptimization（PSO）algorithm. which optimizes the Wavelet Neural Network（WNN）,is used for observing parameters which contain rev. magnetic likage and stator resistance, insteading of conventional velocity generator and magnetic likage sight. Relativing to the problems, such as easily sinking into the part optimal *** speed in astringency. short exactitude in precision and so on. this reformative method divides the optimize particles into two teams, one of them adopts part particleswarmalgorithm which adhibits compressibility factor, the others adopts global particleswarmalgorithm which adhibits inertial weighting, both the local value and the global value can be compromised for improving the astringency speed and precision through combining these two teams. At the same time the network can constitute the link between wavelet transform and network quotiety. which is used for observing parameters. Passed by the validate of experimental result, this kind of reformative PSO algorithm which optimal WNN can fast converge, and it has good exactitude in precision. So it can make the asynchronous dynamo keep high capability, especially in low speed state.
Concrete carbonation was affected by several factors. On the basis of this, the BP networks input vectors were constructed. Through the introduction of PSO algorithm, the connection weights of the model can be optimiz...
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Concrete carbonation was affected by several factors. On the basis of this, the BP networks input vectors were constructed. Through the introduction of PSO algorithm, the connection weights of the model can be optimized, overcoming the shortcomings of the inefficiency in terms of convergence and the great possibility being stuck in a local minimum. The computation indicated that the accuracy and convergence velocity processed by this method is much better than that only adopted by BP algorithm.
In this paper, optimization procedures based on the genetic algorithm, tabu search, ant colony algorithm and particle swarm optimization algorithm were developed for the optimization of machining parameters for millin...
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In this paper, optimization procedures based on the genetic algorithm, tabu search, ant colony algorithm and particle swarm optimization algorithm were developed for the optimization of machining parameters for milling operation. This paper describes development and utilization of an optimization system, which determines optimum machining parameters for milling operations. An objective function based on maximum profit in milling operation has been used. An example has been presented at the end of the paper to give a clear picture from the application of the system and its efficiency. The results are compared and analysed using the method of feasible directions and handbook recommendations.
The polarization mode dispersion (PMD) monitoring system is the key integral part of an adaptive PMD compensator. The degree of polarization (DOP) ellipsoid obtained by using a polarization scrambler can be used as ei...
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ISBN:
(纸本)0819460524
The polarization mode dispersion (PMD) monitoring system is the key integral part of an adaptive PMD compensator. The degree of polarization (DOP) ellipsoid obtained by using a polarization scrambler can be used as either a feedback or feedforward monitoring signal for automatic polarization mode dispersion compensation. Generally, more than several thousands of sampling data of states of polarization (SOP) must be collected to insure getting a correct DOP ellipsoid. This would result in an unacceptable time consuming for adaptive PMB compensation. In this paper, for the first time, we introduce the particleswarmoptimization (PSO) algorithm in determining the real-time DOP ellipsoid with high precision, requiring only 100 sampling data of SOPs. Experimental results confirm that the PSO algorithm is effective for ellipsoid data fitting with high precision within 250ms using our hardware environment.
In this paper we report a successful experiment of adaptive polarization mode dispersion (PMD) compensation up to second-order in a 40Gb/s optical time-division multiplexed (OTDM) communication system by using two-sta...
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ISBN:
(纸本)0819455792
In this paper we report a successful experiment of adaptive polarization mode dispersion (PMD) compensation up to second-order in a 40Gb/s optical time-division multiplexed (OTDM) communication system by using two-stage compensator. In the experiment the PMD monitoring technique based on degree of polarization (DOP) was adopted. And the particleswarmoptimization (PSO) algorithm was introduced in adaptive PMD compensation, with the desirable features of fast convergence to the global optimum point for compensation without being trapped in local sub-optima and with good robustness to noise. The comparison was made to estimate the performance effectiveness between PSO algorithms with global neighborhood structure (GPSO) and with local neighborhood structure (LPSO). The LPSO algorithm is shown to be more effective to search global optimum for PMD compensation than GPSO algorithm. The ability of tracking changed PMD using PSO algorithm was also investigated. The two-stage PMD compensator is shown to be effective for both first- and second-order PMD, and the compensator is shown to be bit rate independent. The compensation time is within several hundreds of milliseconds. The response time for recovery from a sharp disturbance is about 11 ms.
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