共查询到18条相似文献,搜索用时 93 毫秒
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偏振模色散(PMD)已成为高速光纤通信系统中限制单信道传输速率的主要障碍之一.首先介绍了PMD补偿的重要性,随后讨论了现阶段比较可行的主动均衡和补偿PMD的方案,最后介绍了一些抑制PMD效应的新技术. 相似文献
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偏振模色散对波分复用系统的影响及补偿方案研究 总被引:1,自引:0,他引:1
建立多信道WDM通信系统的PMD理论模型,用数值计算方法可得到了波分复用系统传输的波形,发现PMD对各信道的影响是不同的,为波分复用通信系统中PMD补偿提供理论依据.通过一阶偏振模色散局限性的分析,依据波分复用通信系统中PMD的特点,提出了波分复用通信系统中PMD补偿的最坏信道补偿法,并提出了具体的补偿方案. 相似文献
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偏振模色散(PMD)降低了高速光纤通信系统的性能,对于传输速率超过10Gbit/s的系统,PMD的影响尤为严重.文中首先介绍了PMD的基本概念,然后分析了其对高速光纤通信系统性能的影响,最后提出了几种解决方案. 相似文献
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高速光通信中的PMD补偿技术 总被引:1,自引:0,他引:1
偏振模色散(PMD)已成为发展下一代高速长距离光纤通信的主要限制因素,介绍了PMD补偿的基本理论,并分析讨论了一阶、二阶和高阶PMD补偿方法。 相似文献
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文章提出采用粒子群优化算法,提取信号的偏振度(DOP)作为反馈信号来补偿多信道光纤通信系统中的偏振模色散(PMD).作为例子,对两信道的波分复用(WDM)系统中的PMD进行了自动补偿,并进行了数值模拟,得到了两个信道补偿前后的DOP以及眼图变化情况.模拟结果表明这种算法对补偿多个信道的PMD是有效的. 相似文献
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针对光纤传输中的偏振模色散(PMD)问题,研究和比较了现有PMD的光域补偿方法.利用等效啁啾技术,提出了一种基于啁啾光纤光栅的光域补偿方案,用具有光敏性质的保偏光纤制成啁啾光纤光栅,将其作为PMD补偿器中的时延线,实现了PMD的自适应反馈补偿.实验结果显示,该方案能有效补偿光纤传输中的PMD问题,提高光信号的传输质量. 相似文献
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We propose a simple method for tracking and separating time-varying principal states of polarization (PSP) occurring in a fiber-optic transmission link with polarization mode dispersion (PMD) for use in PMD compensation. The proposed method uses as a feedback monitoring signal the bandpass-filtered RF power at bit-rate frequency for NRZ signal format. We demonstrated the operating principle of the method through theoretical simulation and experiment using an automatically adaptive PMD compensator employing a single polarization beam splitter (PBS). The effects of electrical filtering on the PSP tracking performance were also investigated by using three types of filters, i.e., a low-pass filter (LPF), a band-pass filter (BPF), and a high-pass filter (HPF). The simulation results showed that only a BPF centered at bit-rate frequency was found to allow for tracing and separation of two PSPs via PBS. The proposed method, when applied to a conventional PMD compensator that alternately controls a polarization controller and a delay line, enables separation of PSP control from differential-group-delay (DGD) control, thus allowing fast tracking of rapidly changing PSP in a PMD-impaired optical fiber link and reducing compensation time. 相似文献
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A comparison between different PMD compensation techniques 总被引:17,自引:0,他引:17
Sunnerud H. Chongjin Xie Karlsson M. Samuelsson R. Andrekson P.A. 《Lightwave Technology, Journal of》2002,20(3):368-378
We quantify the benefits of using different techniques for compensation of polarization mode dispersion (PMD) in fiber-optic communication systems by means of numerical simulations. This is done both with respect to PMD-induced pulse broadening and in terms of system outage probability for different data formats [nonreturn-to-zero (NRZ) and return-to-zero (RZ)]. Attention is focused on simple and relevant single- and double-stage post-transmission compensators with a few degrees of freedom (DOF). It is generally believed that a PMD compensator with a polarization controller and a variable delay line can only compensate the PMD to the first order. We show, from analytical results, the counterintuitive fact that this scheme can also partially compensate for higher order PMD. We also investigate the benefit of using a polarizer as compensation element where the optical average power can be used as a feedback signal 相似文献
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Polarization mode dispersion (PMD), a potentially limiting impairment in high-speed long-distance fiber-optic communication systems, refers to the distortion of propagating optical pulses due to random birefringences in an optical system. Because these perturbations (which can be introduced through manufacturing imperfections, cabling stresses, installation procedures, and environmental sensitivities of fiber and other in-line components) are unknowable and continually changing, PMD is unique among optical impairments. This makes PMD both a fascinating research subject and potentially one of the most challenging technical obstacles for future optoelectronic transmission. Mitigation and compensation techniques, proper emulation, and accurate prediction of PMD-induced outage probabilities critically depend on the understanding and modeling of the statistics of PMD in installed links. Using extensive data on buried fibers used in long-haul high-speed links, the authors discuss the proposition that most of the temporal PMD changes that are observed in installed routes arise primarily from a relatively small number of "hot spots" along the route that are exposed to the ambient environment, whereas the buried shielded sections remain largely stable for month-long time periods. It follows that the temporal variations of the differential group delay for any given channel constitute a distinct statistical distribution with its own channel-specific mean value. The impact of these observations on outage statistics is analyzed, and the implications for future optoelectronic fiber-based transmission are discussed 相似文献
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提出了一种新偏振模色散(PMD)补偿的方法,直接从被补偿光纤中提取偏振色散矢量的大小和方向信息,根据算法调节偏振模色散补偿器的各参量,使得补偿器的快轴与被补偿光纤的慢轴对准,从而使得偏振模色散得到补偿。这种方法的优点是减少了搜索的自由度。建立了40Gb/s偏振模色散前馈补偿系统,并通过数值模拟.对40Gb/s的非归零(NRZ)码的偏振模色散进行了自适应补偿。通过对补偿前后的眼图、偏振度(DOP)和Q值进行对比和分析,结果表明,这种偏振模色散补偿的前馈方法是非常有效的。 相似文献
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The fluctuation of polarization mode dispersion (PMD) due to environmental change is an important issue for fiber-optic communication systems. We measure the time evolution of PMD for installed aerial and buried cables and for a spooled fiber in a temperature controlled chamber. The results show that PMD fluctuates much more rapidly for aerial cables than for buried cables. The magnitude of PMD is different for the three fibers and our results also show that the magnitude of PMD fluctuation depends on the magnitude of the PMD 相似文献