共查询到19条相似文献,搜索用时 171 毫秒
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1 概述 增加光通信容量的要求刺激人们从对波分复用(WDM)技术的极度重视和加大投资,变成了为满足这一要求而不断选择新技术.那么用光信号进行多路传输的其他技术,例如时分复用(TDM)技术该向何处发展呢?用电子系统执行的传统TDM商品传输速率为10 G bit/s,2001年各公司将推出速率为40 G bit/s的产品.然而,为了使单通道传输的比特率(bit rates)更高,还须在光范畴内进一步增加多路传输,即采用光时分复用(OTDM)技术.与WDM不同,WDM是利用在各分离波长上携带许多相对低带宽的通道信号来实现的;而OTDM是在时域中分割各通道,从而使单个波长能携带极高的数据率.OTDM一般是用一个称之为比特交错传输光纤 相似文献
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提出了解复用窗口匹配滤波器的概念,分析了利用光带通滤波器提高光时分复用(OTDM)频谱效率的光谱压缩技术。基于自制的40Gb/sOTDM复用器,采用电吸收调制器(EAM)及时钟提取模块组成的反馈环路解复用模块,以阵列波导光栅(AWG)作为电吸收采样窗口(EASW)的匹配滤波器对4×10Gbit/sOTDM信号进行光谱压缩,实现了无误码传输100km及传输后的解复用。实验结果表明,AWG的使用使得OTDM信号的频谱效率提高至4倍。 相似文献
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分析了浙江省计算机互联网(CHINANET-ZJ)杭州节点局域网的现状及存在的问题,提出改造杭州节点现有局域网的调整方案。 相似文献
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针对高速率OTDM(光时分复用)系统中的一些关键技术问题,如时钟提取、时分解复用和色散补偿等,提出了8×40Gbit/s的OTDM系统技术方案。结果表明,通过选择合适的时钟提取方式和基于对称性色散位移光纤的色散补偿技术,能够实现在一个时隙内对每个信道的40 Gbit/s归零码信号的解复用,且解复用后的信号质量较好。该系统实现了320Gbit/s OTDM通信。 相似文献
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描述了一套由基于固态半导体电子学技术的0.34 THz无线通信收发前端和基于802.11协议的无线局域网设备实现的0.34 THz无线局域网实验系统。0.34 THz收发前端采用基于肖特基二极管的倍频及混频技术以及基于精密机加工艺的太赫兹无源器件实现,主要由0.34 THz腔体滤波器、0.34 THz谐波混频器、0.17 THz本振倍频链和馈电偏置电路组成。实测结果表明:研制的由3节点组成的0.34 THz无线局域网实验系统可在1.15 m的距离上实现节点间大于800 KB/s的组网通信。 相似文献
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未来全光网中OTDM技术不容忽视 总被引:1,自引:0,他引:1
首先介绍了光时分复用(optical time-division multiplexing,OTDM)技术,接着论述了OTDM从系统到网络的发展及现状,指出OTDM在许多方面具有不可替代的优势。从而说明在未来全光网的建设中OTDM技术将占有非常重要的地位。 相似文献
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首先描述了目前多种光传输体制并存在的局面,然后分别阐述了SDH和DWDM的技术演进以及光网络OTN的核心技术,接着讨论了SDH和DWDM/OTN对IP业务的适应,其中提出了融合节点技术,最后简要论述了OTDM和光孤子的技术问题。 相似文献
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超高速光时分复用(OTDM)技术是当前大容量光纤传榆系统中的研究热点。本文详细讨论了OTDM的全光时分复用、解复用、定时提取等关键技术,并分析了影响OTDM系统性能的因素,最后对超高速OTDM技术的应用前景作了展望。 相似文献
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设计了一种基于OTDM的160Gb/s全光分组网络,介绍了该网络的拓扑结构,解决了该网络的数据包冲突问题和系统偏振模色散问题.实验结果表明,该网络性能稳定,网络吞吐能力强,色散补偿效果明显,大大提高了光纤网络的传输容量,满足光通信各业务需要. 相似文献
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Lei Deng Ying Zhao Xianbin Yu Valeria Arlunno Robert Borkowski Deming Liu Idelfonso Tafur Monroy 《Optical Fiber Technology》2011,(6):554-557
We propose and demonstrate an improved Ethernet passive optical network (EPON) architecture supporting bandwidth-scalable physical layer local area network (LAN) emulation. Due to the use of orthogonal frequency division multiple access (OFDMA) technology for the LAN traffic transmission, there is no need to change the existing EPON architecture. Only one receiver at each optical network unit (ONU) is required to detect both LAN traffic and EPON downstream traffic, which makes the proposed system simple and cost-effective. Moreover, flexible assignment of LAN traffic bandwidth is realized by allocating different number of subcarriers or using different modulation formats. The 250 Mb/s 4-quadrature amplitude modulation (4-QAM) and 500 Mb/s 16-QAM OFDM LAN traffic are successfully emulated with the EPON traffic in our experiment. 相似文献
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The recent advances in optical time division multiplexed (OTDM) systems and components research show the technique to be highly suited to the generation and transmission of high capacity data on a single optical carrier. This approach uses a single wavelength to carry capacities of at least 40 Gb/s. Such systems are based on a clock frequency and tributary data rates which are easily accessible using electronic components. Short optical pulses are used in a return-to-zero data transmission format with temporal interleaving to map a number of optical data channels into a single electronic clock cycle. It is an approach that can be used to achieve extremely high data-rate bit interleaved systems. This article summarizes the developments in this field and outlines a possible methodology to evolve transport networks to encompass the potential that both WDM and OTDM have to offer 相似文献
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Tangdiongga E. Turkiewicz J.P. Rohde H. Schairer W. Lehmann G. Sikora E.S.R. Zhou Y.R. Lord A. Payne D. Khoe G.D. de Waardt H. 《Electronics letters》2004,40(9):552-554
A field-installed 160 Gbit/s OTDM network comprising an OTDM add-drop node placed between two existing fibre links is demonstrated. An excellent performance of signal transmission, subharmonic clock recovery, and add-drop function is reported. 相似文献
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异步环境下,空时协作传输系统的各中继站点无法精确同步,导致不能直接使用正交空时分组码;异步还可能导致采样时刻的不理想,由于脉冲成型滤波器的缘故,使得平衰落信道变成频率选择性衰落信道,严重影响系统性能.针对这些问题,本文提出一种基于单载波频域均衡的异步空时协作传输机制.各中继站点基于正交空时分组码的思想对数据执行逆序共轭等简单操作后发送;目的站点对接收数据进行快速傅立叶变换(FFT)后,通过线性组合分离重叠在一起的数据帧,然后对组合输出的数据执行频域均衡,最后执行快速傅立叶逆变换(IFFT)还原发送数据.由于FFT和IFFT有快速算法,因此新机制有较低的复杂度.理论分析和仿真结果表明:即使在异步环境下,提出的新机制也能获得空时分组码所提供的分集增益. 相似文献
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《Optical Fiber Technology》2007,13(1):1-12
The virtually unlimited bandwidth of optical fibers has caused a great increase in data transmission speed over the past decade and, hence, stimulated high-demand multimedia services. Nowadays, opto-electronic conversion is still required at each network node to process the incoming signal. However, when the single channel bit rate increases beyond electronic speed limit, optical time division multiplexing (OTDM) becomes a forced choice, and all-optical processing must be performed to extract the information from the incoming packet. In this paper the state of art, the advantages and drawbacks of the OTDM technology will be discussed in order to highlight its potentialities in different application scenarios for optical communications networks, and its perspectives in different temporal horizons. In detail, a recent experiment of a 160 Gbit/s OTDM system is presented. Furthermore, a photonic node architecture suitable for optical packet switching networks is proposed, and possible solutions for the implementation of all the required subsystems are presented and compared in order to optimize the node performance. In particular innovative schemes for optical add/drop multiplexer, optical logic gates, optical switches, and optical flip-flop are introduced with a particular emphasis on emerging nonlinear materials and enabling technologies. 相似文献