Showing papers by "Norbert Hanik published in 2009"
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31 Jul 2009TL;DR: This work reviews the most prominent PAPR reduction techniques that have been proposed for mitigating the impairments with regard to their reduction capability, computational complexity and redundancy.
Abstract: In coherent optical OFDM systems, the large peak-to-average power ratio (PAPR) gives rise to signal impairments through the nonlinearity of modulator and fiber. We review the most prominent PAPR reduction techniques that have been proposed for mitigating the impairments with regard to their reduction capability, computational complexity and redundancy. Simulation results are presented for Clipping, Selected Mapping, Active Constellation Extension and Trellis Shaping.
42 citations
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22 Mar 2009TL;DR: Wavelet transform based OFDM is proposed to increase the dispersion tolerance of optical OFDM and for moderate accumulated dispersion the performance is shown to be comparable with Fourier transform based optical OfDM with 10% cyclic prefix.
Abstract: Wavelet transform based OFDM is proposed to increase the dispersion tolerance of optical OFDM. For moderate accumulated dispersion the performance is shown to be comparable with Fourier transform based optical OFDM with 10% cyclic prefix.
20 citations
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TL;DR: The algorithm is used to optimize the fiber launch powers and dispersion map of a single-channel OOK, DPSK and DQPSK at several data rates, considerably reducing the simulation time.
Abstract: We present a global optimization algorithm especially appropriate for the optimization of optical communication systems. It is independent of external parameters and converges to the global optimum, considerably reducing the simulation time. The algorithm is used to optimize the fiber launch powers and dispersion map of a single-channel OOK, DPSK and DQPSK at several data rates.
15 citations
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16 Oct 2009TL;DR: Real-time Gigabit Ethernet transmission over up to 25 m Step-Index Polymer Optical Fibre is demonstrated using a commercial LED enabled by use of PAM-4 modulation and receiver equalisation including clock recovery, implemented in an FPGA.
Abstract: Real-time Gigabit Ethernet transmission over up to 25 m Step-Index Polymer Optical Fibre is demonstrated using a commercial LED. This is enabled by use of PAM-4 modulation and receiver equalisation including clock recovery, implemented in an FPGA.
13 citations
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18 Dec 2009
TL;DR: In this article, a method for processing data in an optical network element is provided, wherein a multicarrier signal is linear pre-coded, and wherein the linear precoded signal is modulated.
Abstract: A method for processing data in an optical network element is provided, wherein a multicarrier signal is linear pre-coded, and wherein the linear pre-coded signal is modulated An according optical network element is also suggested
13 citations
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22 Mar 2009
TL;DR: In this article, a frequency-domain method with good structural properties for reduction of the PAPR in coherent optical OFDM systems was proposed, and it was shown that the nonlinear threshold can be increased considerably at modest redundancy.
Abstract: We propose a frequency-domain method with good structural properties for reduction of the PAPR in coherent optical OFDM systems. Numerical results indicate that the nonlinear threshold can be increased considerably at modest redundancy.
12 citations
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TL;DR: The numerical method is based on the well known Karhunen-Lo;eve expansion combined with a linearization technique of the Nonlinear Schr odinger Equation (NLSE) to account for the nonlinear interaction between signal and noise.
Abstract: Using an alternative approach for evaluating the Bit-Error Rate (BER), we present a numerical and experimental investigation of the performance of phase-modulated optical communication systems in the presence of nonlinear phase noise and dispersion. The numerical method is based on the well known Karhunen-Lo;eve expansion combined with a linearization technique of the Nonlinear Schr odinger Equation (NLSE) to account for the nonlinear interaction between signal and noise. Our numerical results show a good agreement with experiments.
11 citations
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22 Mar 2009TL;DR: In this paper, a global optimization algorithm was used to find the optimum fiber launch powers and dispersion map of single-channel RZ-DPSK and RZDQPSK systems at data rates ranging from 5 Gbps to 130 Gbps.
Abstract: We use a global optimization algorithm to find the optimum fiber launch powers and dispersion map of single-channel RZ-DPSK and RZ-DQPSK systems at data rates ranging from 5 Gbit/s to 130 Gbit/s.
5 citations
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22 Mar 2009TL;DR: In this paper, the authors proposed a novel technique that allows simultaneous detection of two modulated optical subcarriers at high data rates (111Gb/s) using a proof-of-principle experiment.
Abstract: We propose a novel technique that allows simultaneous detection of two modulated optical sub-carriers. A proof-of-principle experiment is described and subsequently the performance at high data rates (111Gb/s) is assessed by simulations.
2 citations
01 Jan 2009
1 citations
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24 Jan 2009TL;DR: Numerical simulations reveal that the use of EPD can significantly increase the tolerance towards PMD in comparison to a system without compensation, and it is shown how to determine appropriate driving signals for a set of measured PMD parameters.
Abstract: One of the major impairments in high-speed optical transmission links is Polarization-Mode Dispersion (PMD). We propose the method of electronic predistortion (EPD) for the mitigation of PMD. This approach has already been successfully applied for the compensation of Chromatic Dispersion (CD) and Fiber-Nonlinearities. The advantage of this method is that impairments can efficiently be mitigated without the need for coherent reception. The proposed scheme is based on the possibility to control the optical field at the transmitter by using two complex modulators for the modulation of two orthogonally polarized optical signals. If the physical origin of PMD is exactly known then the ideal predistorted field and the corresponding electrical driving signals can be computed accurately. In practice, however, this information is not available. Therefore it is shown how to determine appropriate driving signals for a set of measured PMD parameters. Measurements will be communicated through a feedback channel in practice. We suggest a possible strategy for application of this technique in scenarios, in which the adaptation speed is intrinsically limited due to the round-trip delay. Numerical simulations reveal that the use of EPD can significantly increase the tolerance towards PMD in comparison to a system without compensation.