Wyniki wyszukiwania - BazTech

1

Time Domain Simulation of Optical MIMO Channels

Köhnke H., Bartmann P., Ahrens A., Lochmann S.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 4

56--59

EN

In recent years the interest in optical multiple-input multiple-output (MIMO) transmission has increased significantly. Focus of this work is the development of a time domain model of optical MIMO channels using modal diversity. Next to modal and chromatic dispersion, modal crosstalk caused by mode combiner, splitter, splices and also modal coupling within the transmitting fiber can be taken into account. The simulated MIMO impulse responses are validated by practical measurements. The channel measurements confirm the accuracy of the proposed time domain model.

PL

W artykule omawia się optyczny system transmisji typu MIMO (multiple input – multiple output). Zaproponowano model czasowy optycznego kanału MIMO. Wzięto pod uwagę modalną i chromatyczną dyspersję , modalny crosstalk (przesłuch) oraz modalne sprzężenie włókna optycznego.

2

Stable tunable single-longitudinal-mode semiconductor optical amplifier erbium-doped fiber ring lasers for 10 Gbps transmission over 50 km single-mode fiber

Tseng C. L., Liu C. K., Lin Z. R., Chiu C. M., Lai K. C.

Optica Applicata

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2010

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Vol. 40, nr 4

927--933

EN

We demonstrate a stable and tunable single-longitudinal-mode SOA-EDF ring laser for high-speed data transmission systems. The laser is constructed by incorporating an SOA into the EDF ring cavity. The SOA acts as a saturable absorption high-pass filter to suppress cavity mode partition noise at low frequencies. Such design ensures a stable and single-frequency operation for more than several hours. The ring laser has a 30 nm tuning range in the C band and a 0.8 nm wavelength spacing to match 100-GHz ITU-T grids. The variation in the maximum power is smaller than 0.02 dB and the optical signal-to-noise ratio is above 53 dB. By employing this fiber laser, a 10 Gbps non-return zero data transmission over a 50 km long single-mode fiber with a power penalty less than 2.4 dB is demonstrated.

3

Optical network and FPGAlDSP based control system for free electron laser

Romaniuk R. S., Poźniak K.T., Czarski T., Czuba K., Giergusiewicz W., Kasprowicz G., Koperek W.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2005

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Vol. 53, nr 2

123-138

EN

The work presents a structural and functional model of a distributed low level radio frequency (LLRF) control, diagnostic and telemetric system for a large industrial object. An example of system implementation is the European TESLA-XFEL accelerator. The free electron laser is expected to work in the VUV region now and in the range of X-rays in the future. The design of a system based on the FPGA circuits and multi-gigabit optical network is discussed. The system design approach is fully parametric. The major emphasis is put on the methods of the functional and hardware concentration to use fully both: a very big transmission capacity of the optical fiber telemetric channels and very big processing power of the latest series of DSP/PC enhanced and optical I/O equipped, FPGA chips. The subject of the work is the design of a universal, laboratory module of the LLRF sub-system. The current parameters of the system model, under the design, are presented. The considerations are shown on the background of the system application in the hostile industrial environment. The work is a digest of a few development threads of the hybrid, optoelectronic, telemetric networks (HOTN). In particular, the outline of construction theory of HOTN node was presented as well as the technology of complex, modular, multilayer HOTN system PCBs. The PCBs contain critical sub-systems of the node and the network. The presented exemplary sub-systems are: fast optical data transmission of 2.5 Gbit/s, 3.125 Gbit/s and 10 Gbit/s; fast AlC and CIA multichannel data conversion managed by FPGA chip (40 MHz, 65 MHz, 105 MHz), data and functionality concentration, integration of floating point calculations in the DSP units of FPGA circuit, using now discrete and next integrated PC chip with embedded OS; optical distributed timing system of phase reference; and 1 GbEth video interface (over UTP or FX) for CCD telemetry and monitoring. The data and functions concentration in the HOTN node is necessary to make efficient use of the multigigabit optical fiber transmission and increasing the processing power of the FPGAlDSP/PC chips with optical I/O interfaces. The experiences with the development of the new generation of HOTN node based on the new technologies of data and functions concentration are extremely promising, because such systems are less expensive and require less labour.

4

Labeling of signals in optical networks and its applications

Borzycki K.

Journal of Telecommunications and Information Technology

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2004

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nr 2

73-88

EN

The paper is a review and comparative analysis of most common techniques proposed to attach additional data or identification information to digital signals in optical fiber networks by purely optical means. Such "labels" or "headers" can be attached either to continuous bit streams, e.g., in SDH networks or to optical packets. They enable to monitor, route and identify signals in transparent optical networks, especially those with optical wavelength multiplexing, allow management and supervision of remote optical amplifiers and can be used in optical switching systems. Other applications of this relatively unknown technology include monitoring of optical path dispersion, equalization of channels in DWDM systems and detection of intrusion or jamming in highly secure networks.

5

Transmisja światłowodowa ze zwielokrotnieniem falowym : gęściej czy szybciej?

Romaniuk R. S.

Elektronika : konstrukcje, technologie, zastosowania

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2004

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Vol. 45, nr 5

10-15

PL

Najbardziej efektywny, stosowany obecnie światłowodowy system transmisji wielkich ilości informacji bazuje na złożeniu dwóch metod zwielokrotnienia - falowego DWDM i czasowego TDM. Wewnątrz każdego optycznego kanału falowego sygnał podlega zwielokrotnieniu czasowemu. Kanały falowe muszą być odseparowane od siebie. Odstępy międzykanałowe są nieużyteczne pod względem sygnałowym, więc powinny być jak najwęższe. Konieczny jest wybór pomiędzy ilością kanałów optycznych i pasmem elektronicznym. Wybór jednego z rozwiązań wyklucza drugie i ma poważne konsekwencje odnośnie przyszłego rozwoju i fundamentalnych, także ekonomicznych parametrów systemu.

EN

The most effective optical fiber transmission system of large amount of data, used today, bases on concatenation of two multiplexing methods - wave DWDM and time TDM. The signal is multiplexed in time domain inside each optical channel. The wave channels have to be well separated from each other. The separations are useless for transmission spectrum and should be as narrow as possible. It is necessary to choose between the number of optical channels and electronic bandwidth. The choice for denser excludes faster, and vice versa. The choice of these parameters has serious consequences for the further development and basic economic perspectives of the optical transmission system.