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Norbert Hanik

Bio: Norbert Hanik is an academic researcher from Technische Universität München. The author has contributed to research in topics: Transmission (telecommunications) & Wavelength-division multiplexing. The author has an hindex of 28, co-authored 145 publications receiving 2699 citations. Previous affiliations of Norbert Hanik include Deutsche Telekom & Ludwig Maximilian University of Munich.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the transmission behavior of return-to-zero (RZ) and non-return-tozero (NRZ) modulated signals was compared numerically and experimentally.
Abstract: We compared numerically and experimentally the transmission behavior of return-to-zero (RZ) and nonreturn-to-zero (NRZ) modulated signals, 10 Gb/s were transmitted over 2040-km standard single-mode fiber using an alternating dispersion compensation scheme in a recirculating loop with 102 km amplifier spacing. Receiver sensitivities of -33 dBm (NRZ) and -35 dBm (RZ) could be achieved. RZ allows for a simple linear dispersion compensation whereas NRZ suffers from nonlinear signal distortion. NRZ requires under-compensation of the linear chromatic dispersion dependent on signal power and transmission length. Therefore, NRZ makes network design more difficult.

47 citations

Proceedings ArticleDOI
04 Nov 2010
TL;DR: A pilot-tone based phase noise compensation method for the mitigation of nonlinearities in OFDM transmission and allows for the compensation of XPM-induced transmission impairments without direct knowledge of the optical field of the co-propagating channels.
Abstract: We propose a pilot-tone based phase noise compensation method for the mitigation of nonlinearities in OFDM transmission. This scheme allows for the compensation of XPM-induced transmission impairments without direct knowledge of the optical field of the co-propagating channels.

47 citations

Proceedings ArticleDOI
31 Jul 2009
TL;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

Journal ArticleDOI
TL;DR: In this article, the results of a field trial carried out on a Telecom Italia metro link, targeting short data center interconnect applications, were reported, with a net bit rate of 400 Gb/s on a single carrier with 64 quadrature amplitude modulation (QAM) and 128QAM over 156 km.
Abstract: We report on the results of a field trial carried out on a Telecom Italia metro link, targeting short data center interconnect applications. The test-bed presented realistic transmission conditions, such as an average ~0.3-dB/km attenuation and usage of legacy erbium-doped fiber amplifier (EDFA) only. We transmitted a net bit rate of 400 Gb/s on a single carrier with 64 quadrature amplitude modulation (QAM) and 128QAM over 156 km. Error-free transmission over 80 km for single carrier dense wavelength-division multiplexing (DWDM) $30\times 400\text{G}$ 64QAM and $30\times 400\text{G}$ 128QAM (one half of the $C$ -band) is reported. The net spectral efficiency, for both schemes, is 7.11 b/s/Hz.

42 citations

Proceedings ArticleDOI
22 Mar 2015
TL;DR: A digital algorithm for joint pre-compensation of the low-pass frequency response and I/Q skew in transmitters is presented and results for DP-16QAM to DP-256QAM at 37.41 GBaud are presented.
Abstract: We present a digital algorithm for joint pre-compensation of the low-pass frequency response and I/Q skew in transmitters. Experimental results for DP-16QAM to DP-256QAM at 37.41 GBaud are presented.

40 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors summarized the simultaneous transmission of several independent spatial channels of light along optical fibres to expand the data-carrying capacity of optical communications, and showed that the results achieved in both multicore and multimode optical fibers are documented.
Abstract: This Review summarizes the simultaneous transmission of several independent spatial channels of light along optical fibres to expand the data-carrying capacity of optical communications. Recent results achieved in both multicore and multimode optical fibres are documented.

2,629 citations

Journal ArticleDOI
TL;DR: In this paper, the authors give a tutorial overview of OFDM and highlight the aspects that are likely to be important in optical applications, and discuss the constraints imposed by single mode optical fiber, multimode optical fiber and optical wireless.
Abstract: Orthogonal frequency division multiplexing (OFDM) is a modulation technique which is now used in most new and emerging broadband wired and wireless communication systems because it is an effective solution to intersymbol interference caused by a dispersive channel. Very recently a number of researchers have shown that OFDM is also a promising technology for optical communications. This paper gives a tutorial overview of OFDM highlighting the aspects that are likely to be important in optical applications. To achieve good performance in optical systems OFDM must be adapted in various ways. The constraints imposed by single mode optical fiber, multimode optical fiber and optical wireless are discussed and the new forms of optical OFDM which have been developed are outlined. The main drawbacks of OFDM are its high peak to average power ratio and its sensitivity to phase noise and frequency offset. The impairments that these cause are described and their implications for optical systems discussed.

1,761 citations

Journal ArticleDOI
10 Jan 2005
TL;DR: Differential-phase-shift keying has recently been used to reach record distances in long-haul lightwave communication systems and theoretical as well as implementation aspects of DPSK are reviewed.
Abstract: Differential-phase-shift keying (DPSK) has recently been used to reach record distances in long-haul lightwave communication systems. This paper will review theoretical, as well as implementation, aspects of DPSK, and discuss experimental results.

949 citations

Journal ArticleDOI
TL;DR: ACO-OFDM requires less optical power for a given data rate than DCO- OFDM for all but the largest constellations and is better suited to adaptive systems as the same structure is optimum for all constellation.
Abstract: We present theoretical and simulation results for the performance of asymmetrically-clipped optical OFDM (ACO-OFDM) and DC-biased optical OFDM (DCO-OFDM) in AWGN for intensity-modulated direct-detection systems. Constellations from 4 QAM to 1024 QAM are considered. For DCO-OFDM, the optimum bias depends on the constellation size which limits its performance in adaptive systems. ACO-OFDM requires less optical power for a given data rate than DCO-OFDM for all but the largest constellations and is better suited to adaptive systems as the same structure is optimum for all constellations.

638 citations

Journal ArticleDOI
TL;DR: This paper focuses on SDM for fiber-optic communication using few-mode fibers or multimode fibers, in particular on the critical challenge of mode crosstalk, and presents the prospects for SDM in optical transmission and networking.
Abstract: Space-division multiplexing (SDM) uses multiplicity of space channels to increase capacity for optical communication. It is applicable for optical communication in both free space and guided waves. This paper focuses on SDM for fiber-optic communication using few-mode fibers or multimode fibers, in particular on the critical challenge of mode crosstalk. Multiple-input–multiple-output (MIMO) equalization methods developed for wireless communication can be applied as an electronic method to equalize mode crosstalk. Optical approaches, including differential modal group delay management, strong mode coupling, and multicore fibers, are necessary to bring the computational complexity for MIMO mode crosstalk equalization to practical levels. Progress in passive devices, such as (de)multiplexers, and active devices, such as amplifiers and switches, which are considered straightforward challenges in comparison with mode crosstalk, are reviewed. Finally, we present the prospects for SDM in optical transmission and networking.

621 citations