In this paper, data-transmission using the nonlinear Fourier transform for jointly modulated disc... more In this paper, data-transmission using the nonlinear Fourier transform for jointly modulated discrete and continuous spectra is investigated. A recent method for purely discrete eigenvalue removal at the detector is extended to signals with additional continuous spectral support. At first, the eigenvalues are sequentially detected and removed from the jointly modulated received signal. After each successful removal, the time-support of the resulting signal for the next iteration can be narrowed, until all eigenvalues are removed. The resulting truncated signal, ideally containing only continuous spectral components, is then recovered by a standard NFT algorithm. Numerical simulations without a fiber channel show that, for jointly modulated discrete and continuous spectra, the mean-squared error between transmitted and received eigenvalues can be reduced using the eigenvalue removal approach, when compared to state-of-the-art detection methods. Additionally, the computational complex...
This paper reviews key technologies of next generation wavelength division multiplexing passive o... more This paper reviews key technologies of next generation wavelength division multiplexing passive optical networks (WDM-PONs). We have studied WDM-PONs with centralized lightwave source and direct detection, where a wavelength-reuse system is employed to transmit the uplink data by using a colourless transmitter at the optical network unit (ONU). WDM-PON system was demonstrated using a Fabry-Perot laser diode (FP-LD) as a colourless transmitter at the ONU, for Differential phase-shift keying (DPSK) downlink signals and On-off keying (OOK) uplink signals respectively. The constant-amplitude feature of the DPSK modulation could retain great extinction ratio of downlink signal and decrease the noise to the uplink signal. The proposed scheme offers a promising solution for future PONs.
Wavelength Division Multiplexing: A Critical Review
ABSTRACT Optical fiber cable are worldwide installed, e.g. about 43 million kilometers in 1997, a... more ABSTRACT Optical fiber cable are worldwide installed, e.g. about 43 million kilometers in 1997, an annual growth rate of about 20% is expected. This infrastructure is an excellent basis to convert optical networks based on point-to-point systems into managed photonic networks in which new additional photonic equipment is used. Deutsche Telekom started in 1997 some tests with new wavelength division multiplex (WDM) technology in their network in which standard single mode fiber is very dominant. We report on some of these tests and also on first WDM-links in the networking carrying real traffic.
IEE Colloquium on High Speed and Long Distance Transmission
ABSTRACT Optical transmission is mainly influenced by attenuation, chromatic dispersion, nonlinea... more ABSTRACT Optical transmission is mainly influenced by attenuation, chromatic dispersion, nonlinearities and polarization mode dispersion of the fibre. For repeater-free high speed and long haul WDM transmission systems a broadband compensation of chromatic dispersion is required. One of the most effective methods to perform this, is the use of dispersion compensating fibres (DCF) 4×2.5 Gbit/s field transmission experiments were demonstrated over 135 km and a single channel transmission over 4000 km was performed in a recirculating loop testbed. A replica of the Berlin-Darmstadt field transmission line was realized in a laboratory experiment and four 2.5 Gbit/s WDM channels with directly modulated transmitter lasers were transmitted over 750 km. We present the results of field installation of four WDM channels on the Berlin-Darmstadt fibre link, with full dispersion compensation. The link is transparent for all applied data rates up to 10 Gbit/s and wavelengths in the amplifying bandwidth of fibre amplifiers. A 1.3 μm supervisory channel was installed and processed by a line service unit within the fibre amplifiers (EDFA). The link is designed for test applications of commercially available WDM-systems and components
OFC '98. Optical Fiber Communication Conference and Exhibit. Technical Digest. Conference Edition. 1998 OSA Technical Digest Series Vol.2 (IEEE Cat. No.98CH36177), 2000
ABSTRACT The operation, administration, and maintenance (OAM) of a transport network require the ... more ABSTRACT The operation, administration, and maintenance (OAM) of a transport network require the generation, transmission, and detection of OAM signals that are related to each network layer. In the modelled system Gold codes have been applied for transport of the OAM-signals at channels, which have been modulated externally (by Mach-Zehnder modulators) at different modulation levels in order to characterize the influence of the modulation depth. The simulation has shown the feasibility of CDMA for transport of OAM-signals with a bandwidth up to l0-kbit/s per optical carrier in transparent optical networks with minimised distortion of the high speed data stream
2013 18th Optoelectronics and Communications Conference Held Jointly With 2013 International Conference on Photonics in Switching, 2013
ABSTRACT Fiber nonlinearity compensation via expectation maximization is investigated for PDM CO-... more ABSTRACT Fiber nonlinearity compensation via expectation maximization is investigated for PDM CO-OFDM. An improvement in Q-factor of 0.33 dB is observed for 1400-km 100 Gb/s single channel and 1.44 dB for 1000-km 700 Gb/s WDM transmission.
An LDPC coded modulation scheme with probabilistic shaping, optimized interleavers and noniterati... more An LDPC coded modulation scheme with probabilistic shaping, optimized interleavers and noniterative demapping is proposed. Full-field simulations show an increase in transmission distance by 8% compared to uniformly distributed input.
Deployment of 40-Gbit/s technology in metro and core networks is still attractive, to bring down ... more Deployment of 40-Gbit/s technology in metro and core networks is still attractive, to bring down costs and to increase transmission capacity. This paper summarises design issues of 40-Gbit/s WDM systems for their application in wavelength division multiplexed metro and ...
2002 28th European Conference on Optical Communication, Oct 12, 2002
ABSTRACT Optical duobinary transmission over 1720 km is successfully demonstrated in a field tria... more ABSTRACT Optical duobinary transmission over 1720 km is successfully demonstrated in a field trial within a fully transparent German - wide WDM network. This proves the applicability of duobinary modulation for ultra long haul transmission.
... Linear equalization in spectrally efficient Digital Subcarrier Multiplexing for direct detect... more ... Linear equalization in spectrally efficient Digital Subcarrier Multiplexing for direct detection. 5588532 abstract; Rights And Permissions; Gaete, O.; Hellerbrand, S.; Coelho, LD; Spinnler, B.; Hanik, N.; Inst. for Commun. Eng., Tech. Univ. Munchen, Munich, Germany. ...
The mutual information between a complex-valued channel input and its complex-valued output is de... more The mutual information between a complex-valued channel input and its complex-valued output is decomposed into four parts based on polar coordinates: an amplitude term, a phase term, and two mixed terms. Numerical results for the additive white Gaussian noise (AWGN) channel with various inputs show that, at high signal-to-noise ratio (SNR), the amplitude and phase terms dominate the mixed terms. For the AWGN channel with a Gaussian input, analytical expressions are derived for high SNR. The decomposition method is applied to partially coherent channels and a property of such channels called "spectral loss" is developed. Spectral loss occurs in nonlinear fiber-optic channels and it may be one effect that needs to be taken into account to explain the behavior of the capacity of nonlinear fiber-optic channels presented in recent studies.
In this paper, data-transmission using the nonlinear Fourier transform for jointly modulated disc... more In this paper, data-transmission using the nonlinear Fourier transform for jointly modulated discrete and continuous spectra is investigated. A recent method for purely discrete eigenvalue removal at the detector is extended to signals with additional continuous spectral support. At first, the eigenvalues are sequentially detected and removed from the jointly modulated received signal. After each successful removal, the time-support of the resulting signal for the next iteration can be narrowed, until all eigenvalues are removed. The resulting truncated signal, ideally containing only continuous spectral components, is then recovered by a standard NFT algorithm. Numerical simulations without a fiber channel show that, for jointly modulated discrete and continuous spectra, the mean-squared error between transmitted and received eigenvalues can be reduced using the eigenvalue removal approach, when compared to state-of-the-art detection methods. Additionally, the computational complex...
This paper reviews key technologies of next generation wavelength division multiplexing passive o... more This paper reviews key technologies of next generation wavelength division multiplexing passive optical networks (WDM-PONs). We have studied WDM-PONs with centralized lightwave source and direct detection, where a wavelength-reuse system is employed to transmit the uplink data by using a colourless transmitter at the optical network unit (ONU). WDM-PON system was demonstrated using a Fabry-Perot laser diode (FP-LD) as a colourless transmitter at the ONU, for Differential phase-shift keying (DPSK) downlink signals and On-off keying (OOK) uplink signals respectively. The constant-amplitude feature of the DPSK modulation could retain great extinction ratio of downlink signal and decrease the noise to the uplink signal. The proposed scheme offers a promising solution for future PONs.
Wavelength Division Multiplexing: A Critical Review
ABSTRACT Optical fiber cable are worldwide installed, e.g. about 43 million kilometers in 1997, a... more ABSTRACT Optical fiber cable are worldwide installed, e.g. about 43 million kilometers in 1997, an annual growth rate of about 20% is expected. This infrastructure is an excellent basis to convert optical networks based on point-to-point systems into managed photonic networks in which new additional photonic equipment is used. Deutsche Telekom started in 1997 some tests with new wavelength division multiplex (WDM) technology in their network in which standard single mode fiber is very dominant. We report on some of these tests and also on first WDM-links in the networking carrying real traffic.
IEE Colloquium on High Speed and Long Distance Transmission
ABSTRACT Optical transmission is mainly influenced by attenuation, chromatic dispersion, nonlinea... more ABSTRACT Optical transmission is mainly influenced by attenuation, chromatic dispersion, nonlinearities and polarization mode dispersion of the fibre. For repeater-free high speed and long haul WDM transmission systems a broadband compensation of chromatic dispersion is required. One of the most effective methods to perform this, is the use of dispersion compensating fibres (DCF) 4×2.5 Gbit/s field transmission experiments were demonstrated over 135 km and a single channel transmission over 4000 km was performed in a recirculating loop testbed. A replica of the Berlin-Darmstadt field transmission line was realized in a laboratory experiment and four 2.5 Gbit/s WDM channels with directly modulated transmitter lasers were transmitted over 750 km. We present the results of field installation of four WDM channels on the Berlin-Darmstadt fibre link, with full dispersion compensation. The link is transparent for all applied data rates up to 10 Gbit/s and wavelengths in the amplifying bandwidth of fibre amplifiers. A 1.3 μm supervisory channel was installed and processed by a line service unit within the fibre amplifiers (EDFA). The link is designed for test applications of commercially available WDM-systems and components
OFC '98. Optical Fiber Communication Conference and Exhibit. Technical Digest. Conference Edition. 1998 OSA Technical Digest Series Vol.2 (IEEE Cat. No.98CH36177), 2000
ABSTRACT The operation, administration, and maintenance (OAM) of a transport network require the ... more ABSTRACT The operation, administration, and maintenance (OAM) of a transport network require the generation, transmission, and detection of OAM signals that are related to each network layer. In the modelled system Gold codes have been applied for transport of the OAM-signals at channels, which have been modulated externally (by Mach-Zehnder modulators) at different modulation levels in order to characterize the influence of the modulation depth. The simulation has shown the feasibility of CDMA for transport of OAM-signals with a bandwidth up to l0-kbit/s per optical carrier in transparent optical networks with minimised distortion of the high speed data stream
2013 18th Optoelectronics and Communications Conference Held Jointly With 2013 International Conference on Photonics in Switching, 2013
ABSTRACT Fiber nonlinearity compensation via expectation maximization is investigated for PDM CO-... more ABSTRACT Fiber nonlinearity compensation via expectation maximization is investigated for PDM CO-OFDM. An improvement in Q-factor of 0.33 dB is observed for 1400-km 100 Gb/s single channel and 1.44 dB for 1000-km 700 Gb/s WDM transmission.
An LDPC coded modulation scheme with probabilistic shaping, optimized interleavers and noniterati... more An LDPC coded modulation scheme with probabilistic shaping, optimized interleavers and noniterative demapping is proposed. Full-field simulations show an increase in transmission distance by 8% compared to uniformly distributed input.
Deployment of 40-Gbit/s technology in metro and core networks is still attractive, to bring down ... more Deployment of 40-Gbit/s technology in metro and core networks is still attractive, to bring down costs and to increase transmission capacity. This paper summarises design issues of 40-Gbit/s WDM systems for their application in wavelength division multiplexed metro and ...
2002 28th European Conference on Optical Communication, Oct 12, 2002
ABSTRACT Optical duobinary transmission over 1720 km is successfully demonstrated in a field tria... more ABSTRACT Optical duobinary transmission over 1720 km is successfully demonstrated in a field trial within a fully transparent German - wide WDM network. This proves the applicability of duobinary modulation for ultra long haul transmission.
... Linear equalization in spectrally efficient Digital Subcarrier Multiplexing for direct detect... more ... Linear equalization in spectrally efficient Digital Subcarrier Multiplexing for direct detection. 5588532 abstract; Rights And Permissions; Gaete, O.; Hellerbrand, S.; Coelho, LD; Spinnler, B.; Hanik, N.; Inst. for Commun. Eng., Tech. Univ. Munchen, Munich, Germany. ...
The mutual information between a complex-valued channel input and its complex-valued output is de... more The mutual information between a complex-valued channel input and its complex-valued output is decomposed into four parts based on polar coordinates: an amplitude term, a phase term, and two mixed terms. Numerical results for the additive white Gaussian noise (AWGN) channel with various inputs show that, at high signal-to-noise ratio (SNR), the amplitude and phase terms dominate the mixed terms. For the AWGN channel with a Gaussian input, analytical expressions are derived for high SNR. The decomposition method is applied to partially coherent channels and a property of such channels called "spectral loss" is developed. Spectral loss occurs in nonlinear fiber-optic channels and it may be one effect that needs to be taken into account to explain the behavior of the capacity of nonlinear fiber-optic channels presented in recent studies.
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Papers by Norbert Hanik