共查询到20条相似文献,搜索用时 140 毫秒
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利用非线性薛定谔方程,推导计算了考虑偏振模色散和非线性效应情况下,12×40 Gb/s波分复用(WDM)系统中RZ码在不同输入功率下随波长变化的光信号偏振度(DOP),得到不同功率下DOP随着波长λ变化的曲线,同时得到各个信道的眼图.结果表明:通过光信号偏振度的曲线图与眼图的比较,不但明显看出PMD和非线性效应对各个信道的影响是不同的,并且对于WDM系统存在一个最佳输入功率,证实偏振度可以作为WDM系统中监测信道性能的监控信号,这将为实现PMD实时最坏信道补偿提供理论依据. 相似文献
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一种应用于波分复用无源光网络系统中的滤波片-PIN-TIA阵列光接收组件 总被引:3,自引:2,他引:1
设计并实现了一种将密集波分复用(DWDM)薄膜滤波片与光电探测器PIN以及前置放大器TIA集成封装的光接收组件。通过创新设计单模光纤双芯插针和自聚焦透镜的结构,解决了透过密集波分复用滤波片后的反射光偏离轴线带来的耦合问题。并基于该组件实现了32个密集波分复用通道的解复用与信号检测同时完成的波分复用无源光网络(WDM-PON)系统中上行信道阵列接收模块。测试表明模块满足国际电信联盟(ITU-T)中心波长,最小插入损耗为0.3 dB,最大插入损耗为6 dB,响应速率为100 Mbit/s~1.25 Gbit/s。 相似文献
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基于F-P滤波器的多波长时钟提取 总被引:1,自引:0,他引:1
提出一种简单的全光单一链路的多波长时钟同时提取方案。利用Fabry-Perot(F-P)滤波器对波分复用(WDM)系统中多波长的归零(RZ)码信号进行时钟提取,滤波器后面接半导体光放大器(SOA)对F-P滤波器提取出的时钟进行整形处理,通过实验证实了用F-P滤波器对两路不同波长的10 Gbps信号时钟提取的可行性以及同一SOA同时处理双波长时钟的能力,两路提取时钟的单边带相位噪声分别达到-82.815和-83.072dBc/Hz@10 kHz。 相似文献
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基于FPGA的多路E1信道的MPEG-2码流传输 总被引:1,自引:0,他引:1
阐述了多E1信道的复用、反向复用技术,并由此设计出了一种基于现场可编程门阵列(FPGA)的MPEG-2码流的多E1信道复用器、反向复用器电路。分析了FPGA具体实现过程中的一些常见问题,以及传输路由引起的多信道之间的信道时延差对接收端数据复用的影响。该设计实现了MPEG-2码流、控制码数据在多路E1信道中的透明传输,适配FPGA电路内置帧发生器和n(n=2,3,4)倍2.048MHz时钟发生器。 相似文献
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基于Ethemet over E1的原理,结合通用嵌入式芯片的功能特点,辅以现场可编程器件,介绍了Ethemet over E1网桥系统中核心部分的设计,包括网桥的系统统构、HDLC接口模块的嵌入式程序设计和E1接口电路的FPGA设计.E1接口电路分为数据接收、时隙选择、时钟产生、数据发送四大模块,用FPGA逐一实现.有关设计经过多次软硬件联合仿真验证后,在基于嵌入式系统的网桥项目中通过了板级的功能测试和验证,取得到了较好的效果. 相似文献
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Aisawa S. Kani J.-I. Fukui M. Sakamoto T. Jinno M. Norimatsu S. Yamada M. Ono H. Oguchi K. 《Lightwave Technology, Journal of》1999,17(2):191-199
This paper reports 1580-nm band wavelength division multiplexed (WDM) transmission employing optical duobinary coding over dispersion-shifted fibers. By using the 1580 nm band, the generation of four-wave mixing (FWM) over dispersion-shifted fibers (DSFs) can he suppressed. Optical duobinary coding is dispersion-tolerant because of its narrow bandwidth, and enables the use of the conventional binary intensity modulated direct detection (IM-DD) receiver. First, comparisons are made for WDM transmission performance in the 1580-nm band between conventional binary nonreturn-to-zero (NRZ) coding with and without postdispersion compensation, and optical duobinary coding by computer simulation is described. From the numerical simulations, it is found that the optical duobinary coding has superior transmission performance to the conventional binary coding without any dispersion compensation, and that the difference in the transmission performance between two coding methods is very small even if postdispersion compensation at the optical receiver is applied to the NRZ coding method. Second, transmission performance between the conventional binary NRZ and the optical duobinary signals without any dispersion compensation is compared with the straight-line experiment over 500-km dispersion-shifted fiber. The experimental results reveal that the transmission distance with optical duobinary coding is doubled in comparison with that of the conventional binary NRZ signals. Finally, 16-channel, 10-Gb/s optical duobinary WDM signals in the 1580-nm band are successfully transmitted over 640 km (80 km×8) of DSF without any dispersion compensation or management 相似文献
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Nezam S.M.R.M. Yong-Won Song Changyuan Yu McGeehan J.E. Sahin A.B. Willner A.E. 《Lightwave Technology, Journal of》2004,22(4):1086-1093
We propose and demonstrate two novel techniques for 10 Gb/s polarization-mode-dispersion (PMD) monitoring for NRZ signals that use a regenerated RF clock tone as a monitoring signal. Our techniques regenerate the RF clock tone that is usually absent after square-law detection in the electrical NRZ data spectrum (in the absence of dispersion). Our first technique uses a dispersive element in the monitoring tap-line to put the beat terms between the optical clock sidebands and the carrier in phase and thus regenerates the RF clock tone after detection. Our second technique involves the use of an optical filter that is centered at the bit rate frequency on either the upper or lower sideband of the optical spectrum, removing one of the sidebands and thus preventing the beating that normally cancels the RF clock tone. We show (theoretically, via simulation, and experimentally) the effect that PMD has on these regenerated RF clock tones. We also demonstrate PMD compensation at 10 Gb/s using these techniques for monitoring and show a 6-dB improvement in the 1% power penalty tail. Our techniques are simple, do not require modification at the transmitter, and can be applied to WDM systems via the use of a multichannel dispersive element or a tunable filter swept across all channels. 相似文献
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Optical integrated switching systems using collinear acoustooptic (AO) interactions for wavelength division multiplexing (WDM) systems are discussed. The AO switch module has excellent advantages compared to electrooptic switches. Optical WDM signals can be wavelength-selectively switched by frequency multiplexed surface acoustic waves. WDM switching systems are proposed as an application of this AO switch, and optical insertion loss, crosstalk, and optical frequency shift are discussed. Wavelength-selective characteristics in the AO module are established. The crosstalk from other wavelengths is found to be reduced by decreasing slightly the switching transfer efficiency. The wavelength-selective switching was experimentally demonstrated with a slab-type module of a 4-mm interaction region, where the WDM interval of 25.2 Å was realized. This wavelength interval can be decreased by increasing the interaction length 相似文献
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波分复用(wavelength-Division Multiplexing,WDM)技术的发展大大提高了通信网络的传输容量,将成为下一代骨干网络的核心传输方式.在WM系统光网元设备之间的通信方法中,较多的是采用光监控信道(OSC)和调顶技术(Pilot Tone),但是这两种方法的固有缺陷在城域波分系统不可避免,从而引出电监控信道(ESC)一适用于城域波分系统的基于业务开销中现有的DCC字节来进行网元之间通信的一种实现方法.该方法易于实现、可靠性高,有效降低了系统成本,提高了系统资源利用率,有较好的应用前景. 相似文献
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10频道无再生中继使用光纤放大器的波分复用光纤传输实验系统 总被引:1,自引:0,他引:1
在国内首次研制了10频道、102km无再生中继使用1个平坦增益光纤放大器的WDM光纤传输实验系统。每频道传输码率为140Mb/s(2^23-1 NRZ PRBS或CMI PRBS)。系统全部采用国产DFB激光器,它们的波长分别为1531nm、1535nm、1537nm、1545nm、1547nm、1549nm、1551nm、1559nm、1561nm,在波长为1551nm的频道内布置了2路频率间隔 相似文献
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Yoneyama M. Miyamoto Y. Otsuji T. Toba H. Yamane Y. Ishibashi T. Miyazawa H. 《Lightwave Technology, Journal of》2000,18(1):34-43
This paper presents a fully electrical 40-Gb/s time-division-multiplexing (TDM) system prototype transmitter and receiver. The input and output interface of the prototype are four-channel 10-Gb/s signals. The prototype can be mounted on a 300-mm-height rack and offers stable 40-Gb/s operation with a single power supply voltage. InP high-electron mobility transistor (HEMT) digital IC's perform 40-Gb/s multiplexing/demultiplexing and regeneration. In the receiver prototype, unitraveling-carrier photodiode (UTC-PD) generates 1 Vpp output and directly drives the InP HEMT decision circuit (DEC) without any need for an electronic amplifier. A clock recovery circuit recovers a 40-GHz clock with jitter of 220 fspp from a 40-Gb/s nonreturn-to-zero (NRZ) optical input. The tolerable dispersion range of the prototype within a 1-dB penalty from the receiver sensitivity at zero-dispersion is as wide as 95 ps/nm, and the clock phase margin is wider than 70° over almost all the tolerable dispersion range. A 100-km-long transmission experiment was performed using the prototype. A high receiver sensitivity [-25.1 dBm for NRZ (27-1) pseudorandom binary sequence (PRBS)] was obtained after the transmission. The 40-Gb/s regeneration of the InP DEC suppressed the deviation in sensitivity among output channels to only 0.3 dB. In addition, four-channel 40-Gb/s wavelength-division-multiplexing (WDM) transmission was successfully performed 相似文献