共查询到20条相似文献,搜索用时 15 毫秒
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基于等效相移超结构光纤光栅编解码器的2.5 Gbit/s 60 km光码分多址传输实验 总被引:6,自引:2,他引:4
稳定的窄脉冲光源、高性能编解码器和具有旁瓣/噪声抑制功能的接收机是光码分多址(OCDMA)系统设计实现的3个关键模块。实验中利用增益开关脉冲光源,63位等效相移超结构布拉格光栅(EPS-SSFBG)相位编解码器和接收机门限调整技术实现了2.5 Gbit/s 60 km传输并得到了相应的误码曲线,系统在误码率(BER)等于10-9时的灵敏度为-22.5 dBm。实验结果表明,等效相移超结构布拉格光栅编解码器兼具高性能和可实现性,可用于实用化的光码分多址系统,而综合利用光域和电域的手段抑制旁瓣和噪声的影响是提高系统性能的重要手段。 相似文献
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Tao Pu Yingxun Zhu Peng Chen Xiangfei Chen Lin Lu Rong Wang Yuquan Li Jilin Zheng 《Photonics Technology Letters, IEEE》2007,19(22):1807-1809
Optical code-division multiple-access (OCDMA) technology is attractive for optical broadband access network. It is very interesting to use the super-structure fiber-Bragg-grating-based en/decoders to construct a wavelength-division-multiplexing (WDM)-compatible OCDMA system. Based on the equivalent phase-shift technique, we have proposed a subsampled-Bragg-grating (S-SBG)-based en/decoder. Based on the proposed method, only a single uniform phase mask can be used to accommodate different WDM channels with relevant central wavelengths and spectrum width. Using the S-SBG-based en/decoder, we can make different WDM channels have similar as well as better encoding efficiency and correlation performance. S-SBG-based en/decoders with 127 chips for two different wavelength channels are fabricated and measured. The experiments indicate the advantages revealed by the theoretical simulation. 相似文献
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Ye Zhang Hongwei Chen Zhijian Si Heng Ji Shizhong Xie 《Photonics Technology Letters, IEEE》2008,20(11):891-893
A novel fiber Bragg grating (FBG)-based en/decoder for the two-dimensional (2D) time-spreading wavelength-hopping optical coding is proposed. Compared with other 2D en/decoders, the proposed en/decoding for an optical code-division multiple-access (OCDMA) system uses a single phase-encoded FBG and coherent en/decoding. Furthermore, combined with reconstruction-equivalent-chirp technology, such en/decoders can be realized with a conventional simple fabrication setup. Experimental results of such en/decoders and the corresponding system test at a data rate of 5 Gb/s demonstrate that this kind of 2-D FBG-based en/decoders could improve the performances of OCDMA systems. 相似文献
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We propose a new optical code division multiple access (OCDMA) scheme for reducing multiple access interference (MAI) and enhancing performance for optical subscriber access networks using modified pseudorandom noise (PN)‐coded fiber Bragg gratings with bipolar OCDMA decoders. Through the bipolar OCDMA decoder and the modified PN codes, MAI among users is effectively depressed. As the data are encoded either by a unipolar signature sequence of the modified PN code or its complement according to whether the data bit is 1 or 0, the bit error ratio (BER) can be more improved with the same signal to interference plus noise ratio over the conventional on‐off shift keying‐based OCDMA system. We prove by numerical analysis that the BER of the proposed bipolar OCDMA system is better than the conventional unipolar OCDMA system. We also analyze the spectral power distortion effects of the broadband light source. 相似文献
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《Lightwave Technology, Journal of》2009,27(3):299-305
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Zhaowei Zhang Tian C. Petropoulos P. Richardson D.J. Ibsen M. 《Photonics Technology Letters, IEEE》2007,19(8):574-576
We propose and demonstrate new optical code-division multiple-access (OCDMA) encoder-decoders having a continuous phase-distribution. With the same spatial refractive index distribution as the reconfigurable optical phase encoder-decoders, they are inherently suitable for the application in reconfigurable OCDMA systems. Furthermore, compared with conventional discrete-phase devices, they also have additional advantages of being more tolerant to input pulsewidth and, therefore, have the potential of bandwidth saving 相似文献
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Fully programmable ring-resonator-based integrated photonic circuit for phase coherent applications 总被引:1,自引:0,他引:1
Agarwal A. Toliver P. Menendez R. Etemad S. Jackel J. Young J. Banwell T. Little B.E. Chu S.T. Wei Chen Wenlu Chen Hryniewicz J. Johnson F. Gill D. King O. Davidson R. Donovan K. Delfyett P.J. 《Lightwave Technology, Journal of》2006,24(1):77-87
A novel ring-resonator-based integrated photonic chip with ultrafine frequency resolution, providing programmable, stable, and accurate optical-phase control is demonstrated. The ability to manipulate the optical phase of the individual frequency components of a signal is a powerful tool for optical communications, signal processing, and RF photonics applications. As a demonstration of the power of these components, we report their use as programmable spectral-phase encoders (SPEs) and decoders for wavelength-division-multiplexing (WDM)-compatible optical code-division multiple access (OCDMA). Most important for the application here, the high resolution of these ring-resonator circuits makes possible the independent control of the optical phase of the individual tightly spaced frequency lines of a mode-locked laser (MLL). This unique approach allows us to limit the coded signal's spectral bandwidth, thereby allowing for high spectral efficiency (compared to other OCDMA systems) and compatibility with existing WDM systems with a rapidly reconfigurable set of codes. A four-user OCDMA system using polarization multiplexing is shown to operate at data rates of 2.5 Gb/s within a 40-GHz transparent optical window with a bit error rate (BER) better than 10/sup -9/ and a spectral efficiency of 25%. 相似文献
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Liqiao Qin Hongxi Yin Wei Liang Ziyu Wang Anshi Xu 《Photonic Network Communications》2008,15(1):19-24
In this article, an M-code keying OCDMA system with parallel encoders/decoders is presented and its security performance is
quantitatively analyzed. Under brute-force searching techniques, the formula about the average searching time is derived.
The bit-correct-interception possibilities for tapping individual and multiple users’ signals are calculated, respectively.
By analysis, it is shown that the security performance of an OCDMA system can be enhanced by employing M-code keying. 相似文献
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光码分多址技术及其编解码器的研究 总被引:2,自引:0,他引:2
在简要介绍了光码分多址 ( OCDMA)技术原理的基础上 ,对地址码及几种主要码集、主要光编、解码器结构进行较详细的讨论 ,同时给出了 OCDMA与 WDM竞争的技术条件。另外介绍了一种新的解相关解码器原理。最后给出了 OCDMA的关键技术。 相似文献
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Huiszoon B. de Waardt H. Khoe G.D. Koonen A.M.J. 《Photonics Technology Letters, IEEE》2008,20(4):276-278
In this letter, we show, for the first time, that an integrated spectral optical code-division multiple-access (OCDMA) technique has a comparable performance with respect to coherent OCDMA techniques based on a crosstalk analysis. The code set is further studied on its resilience against imbalances in the 3-dB couplers of the en/decoders (E/Ds). The orthogonality remains acceptable for imbalance penalties up to 1 dB. The analysis done in the letter considers a cascade and a tree E/D which shows negligible differences in performance. 相似文献
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为了得到性能较为良好的正交码,采用没有重复数字的全间隔集,进行了地址码的设计和系统仿真验证,设计出的正交码具有理想的相关性和灵活的码字容量。分析整个系统,在考虑各种噪声和多址干扰的影响下,推导出正交码的误比特率公式。自行设计并搭建了采用光纤延时线作为编解码器的异步光码多分址系统。结果表明,该正交码能够适应更多用户的需求,通过误比特率公式计算和系统仿真得到的结果都较为理想,此研究对需要大容量的光码多分址系统的进一步发展具有一定的帮助。 相似文献
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《Photonics Technology Letters, IEEE》2009,21(24):1795-1797
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采用光码分多址技术的高速计算机局域网 总被引:8,自引:0,他引:8
本文提出一种可行的适于高速计算机网络的光码分多址技术,该网络采用光正交码和光信号处理,以保证实时数据通信。提出的全光结构的快速可调光正交码编码器和解码器,可在光域中用电光开关和光延迟线实现,能支持超高速吞吐量且重构时间很短 相似文献
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For the first time to the authors' knowledge a design procedure of OCDMA en/decoders based on superstructured fibre Bragg gratings employing synthesis methods is proposed and experimentally demonstrated. Experimental results show a clear reduction of the insertion losses, maintaining unaltered the en/decoding capabilities in comparison with standard weaker devices. 相似文献
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