The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
M. S. Islam - One of the best experts on this subject based on the ideXlab platform.
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Analysis of XPM effect with SPM and GVD in WDM fiber Optic Transmission System
2012 International Conference on Computer and Communication Engineering (ICCCE), 2012Co-Authors: Nasrin Sultana, M. S. IslamAbstract:Increased channel capacity of Optical Transmission System is obtained either by increasing the bit rate of Transmission or by using the technique of wavelength division multiplexing (WDM). In long distance communication, higher launched power is required to achieve the required signal to noise ratio. But with the increased launched Optical powers, bit rates and the number of wavelength channels, the nonlinear Optical effects have been increased. Also, at high bit rate, group velocity dispersion (GVD) limits the Transmission distance. Cross-phase modulation (XPM) is an important nonlinear impairment that causes interference through intensity-dependent phase shifts between two Optical fields in Optical networks using WDM. This effect limits the allowable input Optical power and System capacity. The XPM effect with SPM and GVD degrade the System performances significantly. In this research work, a detail analysis have been done to find the mathematical expression for pulse broadening factor by solving nonlinear Schrödinger equation (NLSE) considering the effects of XPM with SPM and GVD in WDM System. By using this mathematical expression, pulse broadening factor has been visualized. The results are evaluated at different bit rates, different input power and varying Transmission distance.
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Comparitive study on the effects of XPM with SPM & GVD and SPM with CD in WDM fiber Optic Transmission System
2012 7th International Conference on Electrical and Computer Engineering, 2012Co-Authors: Nasrin Sultana, M. S. IslamAbstract:In fibre Optic Transmission System self phase modulation (SPM) and cross phase modulation (XPM) cause interference between Optical fields. The allowable input power and System capacity are limited by these effects. Also at high bit rate the Transmission distance is limited by group velocity dispersion (GVD). In this research paper the comparison between the effect of XPM with SPM & GVD and SPM with CD on Optical pulse have been done in terms of pulse broadening factor. The result have evaluated at different bit rate and different input power.
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Analysis and simulation of polarization mode dispersion effects on high bit-rate fiber-Optic Transmission System
2012 7th International Conference on Electrical and Computer Engineering, 2012Co-Authors: Rubayet Shafin, Saikat Basak, Aynul Islam, S. P. Majumder, M. S. IslamAbstract:Simulation is presented on the effects of polarization mode dispersion (PMD) as a source of System impairment in high bit-rate fiber-Optic Transmission Systems. A simulation model is introduced that illustrates how the differential group delay (DGD) affects the bit error rate (BER) limiting the System performance. Power penalty due to PMD is determined from both the eye diagram and BER curve and their mutual consistency is verified. As a PMD compensation scheme, in this paper, a polarization controller (PC) is used and the performance of two Systems with and without PC is compared. Results show that at a bit rate of 10 Gbps, for a DGD of 80 ps, power penalty can be improved by about 1.25 dB when using a polarization controller in the System.
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Impact of XPM in WDM fiber-Optic Transmission System in presence of second order GVD
International Conference on Electrical & Computer Engineering (ICECE 2010), 2010Co-Authors: M. Khayer A. Azad, M. S. IslamAbstract:In wavelength division multiplexing (WDM) Optical Transmission System, crosstalk due to cross-phase modulation (XPM) is one of the most significant nonlinear effect. On the other hand in a first order group velocity dispersion (GVD) compensated System, second order GVD also restricts bit rate. This paper presents an analytical treatment of XPM effect in presence of second order GVD in WDM fiber-Optic Transmission System. It is found that in long haul high bit rate System, second order GVD plays a critical role in limiting performance in a WDM System. Results show that XPM crosstalk penalty in presence of second order GVD is 43 dB more for dispersion shifted fiber than standard single mode fiber at 10 GHz modulation frequency and 0.8 nm channel spacing.
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Suppression of stimulated Brillouin scattering effect using nonlinear phase modulation
International Conference on Electrical & Computer Engineering (ICECE 2010), 2010Co-Authors: F. H. Tithi, M. S. IslamAbstract:Achieving maximum Optical amplifier or repeater spacing in fiber-Optic Transmission System is compromised by the input power limit due to stimulated Brillouin scattering (SBS). In digital Transmission, SBS causes bit error rate degradation. In this paper, we have established analytical model for spectral broadening due to self-phase- and cross-phase modulation and using this broadening, SBS effect is significantly suppressed by raising the SBS threshold power level. The spectral width of propagating signal broadens due to nonlinear phase modulation which ultimately increases the SBS threshold power and results transfer of relatively high Optical power as well as longer span length without backscattering.
Stuart D. Walker - One of the best experts on this subject based on the ideXlab platform.
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Ultrabroadband Wireless–Optical Transmission Links Using Axial Slot Leaky Feeders and Optical Fiber for Underground Transport Topologies
IEEE Transactions on Vehicular Technology, 2008Co-Authors: Sandra E. M. Dudley, Terence J. Quinlan, Stuart D. WalkerAbstract:This paper describes a hybrid leaky feeder/fiber-Optic Transmission System for use in underground transportation networks. The System has a 1.6-Gb/s throughput and features an ultrawideband axial slot leaky feeder, which is based on a standard semirigid coaxial cable as a fixed antenna. Patch antennas with a 4-GHz center frequency and a 1-GHz, -10-dB bandwidth are proposed for the rolling stock. This highest reported data rate was achieved by combining two 800-Mb/s in-phase and quadrature (I and Q) phase-shift keying (PSK) modulated data streams. A specially designed carrier and data synchronization System provided a convenient interface to a 1.3/1.5-mum diplex single-mode fiber-remoting network. The measured 2.4- to 6-GHz leaky feeder bandwidth allows multiradio multiband wireless mesh networking and, therefore, low-contention gigabit rolling stock data communications.
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1.6Gb/s Data Throughput Optically-Remoted Leaky Feeders for Underground Transport Environments
2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring, 2007Co-Authors: Sandra E. M. Dudley, Terence J. Quinlan, Stuart D. WalkerAbstract:In this paper the authors describe a hybrid leaky feeder, fiber-Optic Transmission System for use in underground transportation networks. The System described has a Transmission rate of 1.6 Gb/s and features an ultra wideband, axial-slot leaky feeder, based on standard semi-rigid coaxial cable as a fixed antenna. Patch antennas with a 4 GHz center frequency and 1 GHz, -10 dB bandwidth are proposed for the rolling stock. This highest reported data rate was achieved by combining two 800 Mb/s in-phase and quadrature (I and Q) PSK modulated data streams. A specially designed carrier and data synchronization System provided a convenient interface to a 1.3/1.5 mum diplex single mode fiber-remoting network. The measured 2.4 - 6 GHz leaky feeder bandwidth allows multi-radio, multi-band wireless mesh networking and therefore low-contention gigabit rolling stock data communications.
Masayuki Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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information rate analysis of a fiber Optic Transmission System including 2r signal regenerators
Optics Express, 2013Co-Authors: Masayuki MatsumotoAbstract:Performance of a single-channel fiber-Optic Transmission System in which signal regenerators are periodically inserted is analyzed in terms of information rate (IR) considering channel memory. Limitations in using regenerators in a System having non-zero residual dispersion between the regenerators are discussed. It is shown that a type of signal impairment caused by the interaction between the Transmission-fiber dispersion and the regenerator nonlinearity is pattern-dependent and will be mitigated by the use of sequence estimation after detection at the receiver.
Ergin Atalar - One of the best experts on this subject based on the ideXlab platform.
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miniaturized fiber Optic Transmission System for mri signals
Magnetic Resonance in Medicine, 2008Co-Authors: Omer Gokalp Memis, Yigitcan Eryaman, Orhan Aytur, Ergin AtalarAbstract:Conventional MRI instruments transmit received MRI signals through electrical cables. Although this design has proved to be effective over the years, we report a fiber-Optic System that addresses the needs of recent developments in MRI technology. One of these technologies is phased array coils with a high number of elements, where total size of interconnections is a primary problem, and other problem is internal MRI coils, where there is a need for improvements in safety. The Miniature FiberOptic Transmission (FOT) System was developed to address these issues. The System consists of a receiver coil with active detuning, a low-noise preamplifier, and a laser diode connected to a photodetector with fiber-Optic cabling. The overall noise figure of the System is lower than 1 dB. Total power consumption is 50 mW, and the device is switchable with another fiberOptic line, which can also control active detuning. A prototype device was tested in a GE 1.5 Tesla MRI scanner, and several images were acquired with a signal to noise ratio similar to coaxial cabling. We believe that this design will reduce the cabling problems of arrays and enable placement of internal coils into body cavities with no safety hazard to the patient, such as electrical shock or burns. Magn Reson Med 59: 165–173, 2008. © 2007 Wiley-Liss, Inc.
Sandra E. M. Dudley - One of the best experts on this subject based on the ideXlab platform.
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Ultrabroadband Wireless–Optical Transmission Links Using Axial Slot Leaky Feeders and Optical Fiber for Underground Transport Topologies
IEEE Transactions on Vehicular Technology, 2008Co-Authors: Sandra E. M. Dudley, Terence J. Quinlan, Stuart D. WalkerAbstract:This paper describes a hybrid leaky feeder/fiber-Optic Transmission System for use in underground transportation networks. The System has a 1.6-Gb/s throughput and features an ultrawideband axial slot leaky feeder, which is based on a standard semirigid coaxial cable as a fixed antenna. Patch antennas with a 4-GHz center frequency and a 1-GHz, -10-dB bandwidth are proposed for the rolling stock. This highest reported data rate was achieved by combining two 800-Mb/s in-phase and quadrature (I and Q) phase-shift keying (PSK) modulated data streams. A specially designed carrier and data synchronization System provided a convenient interface to a 1.3/1.5-mum diplex single-mode fiber-remoting network. The measured 2.4- to 6-GHz leaky feeder bandwidth allows multiradio multiband wireless mesh networking and, therefore, low-contention gigabit rolling stock data communications.
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1.6Gb/s Data Throughput Optically-Remoted Leaky Feeders for Underground Transport Environments
2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring, 2007Co-Authors: Sandra E. M. Dudley, Terence J. Quinlan, Stuart D. WalkerAbstract:In this paper the authors describe a hybrid leaky feeder, fiber-Optic Transmission System for use in underground transportation networks. The System described has a Transmission rate of 1.6 Gb/s and features an ultra wideband, axial-slot leaky feeder, based on standard semi-rigid coaxial cable as a fixed antenna. Patch antennas with a 4 GHz center frequency and 1 GHz, -10 dB bandwidth are proposed for the rolling stock. This highest reported data rate was achieved by combining two 800 Mb/s in-phase and quadrature (I and Q) PSK modulated data streams. A specially designed carrier and data synchronization System provided a convenient interface to a 1.3/1.5 mum diplex single mode fiber-remoting network. The measured 2.4 - 6 GHz leaky feeder bandwidth allows multi-radio, multi-band wireless mesh networking and therefore low-contention gigabit rolling stock data communications.
