| 11. |
- Kylemark, Per, 1976, et al.
(author)
-
Noise statistics of fiber optical parametric amplifiers
- 2006
-
In: OFC/NFOEC 2006. 2006 Optical Fiber Communication Conference and National Fiber Optic Engineers Conference. ; , s. OWT5-
-
Conference paper (peer-reviewed)abstract
- We show both theoretically and experimentally that the probability density function of a signal amplified by parametric amplifiers with pump excess noise is non-Gaussian and asymmetric. This impacts the relationship between the noise figure and the bit-error rate
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| 12. |
- Lu, Guo-Wei, 1976, et al.
(author)
-
Format Conversion From 120-Gb/s RZ-D8PSK to 80-Gb/s RZ-DQPSK Through FWM-Based Optical Phase Erasure
- 2010
-
In: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 22:24, s. 1817-1819
-
Journal article (peer-reviewed)abstract
- An optical format conversion scheme from 120-Gb/s return-to-zero differential 8-ary phase-shift keying (RZ-D8PSK) to 80-Gb/s RZ differential quadrature phase-shift keying (RZ-DQPSK) is demonstrated by optically removing one tributary through optical phase erasure. It is achieved through four-wave mixing in a highly nonlinear fiber. An 8-dB sensitivity improvement is obtained for the converted DQPSK signal relative to that of the input D8PSK signal. This is potentially useful to enable the interconnection among neighboring networks where different formats are deployed.
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| 13. |
- Lu, Guo-Wei, 1976, et al.
(author)
-
Format Conversion of Optical Multilevel Signals Using FWM-Based Optical Phase Erasure
- 2011
-
In: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 29:16, s. 2460-2466
-
Journal article (peer-reviewed)abstract
- An optical format conversion scheme of multilevel phase-shift keying (M-ary PSK) signals using the four-wave mixing based optical phase erasure is discussed in this paper. The conversion from differential quadrature phase-shift keying (DQPSK) to differential phase shift keying at 10 and 160 Gbaud, and the conversion from differential eight-ary phase-shift keying to DQPSK at 40 Gbaud have been experimentally demonstrated. The proposed scheme could be used as a phase erasure, in which a redundant tributary of the M-ary PSK signal is removed, or as an "updater" where the unwanted phase pattern is replaced with the new pattern.
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| 14. |
- Peng, Fangrong, 1986, et al.
(author)
-
Operational Regime of Symbol-by-Symbol Phase Noise Estimation for POLMUX 16-QAM
- 2010
-
In: Proceedings of European Conference on Optical Communication, ECOC, Turin, Italy, September 19-23, 2010. - 9781424485352
-
Conference paper (peer-reviewed)abstract
- A symbol-by-symbol phase noise estimation algorithm for polarization-multiplexed 16-QAM is evaluated. We found that it can cope with laser linewidths of up to 2.2 MHz in high SNR regimes, at 112 Gbit/s.
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| 15. |
- Sen, Debarati, 1975, et al.
(author)
-
MCRB for Timing and Phase Offset for Low-Rate Optical Communication with Self-Phase Modulation
- 2013
-
In: IEEE Communications Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-2558 .- 1089-7798. ; 17:5, s. 1004-1007
-
Journal article (peer-reviewed)abstract
- We derive the modified Cramer-Rao bound (MCRB) for symbol timing and phase offset estimation in the presence of nonlinear self-phase modulation (SPM) in a dispersion compensated long-haul optical fiber link with coherent detection at data rates below 10 Gigabaud. In the presence of a low-pass filter at the receiver front-end, we find that SPM degrades the MCRB. Moreover, depending on the pulse shape, SPM induces underdamped oscillation on the bounds.
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| 16. |
- Sjödin, Martin E, 1983, et al.
(author)
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Comparison of polarization-switched QPSK and polarization-multiplexed QPSK at 30 Gbit/s
- 2011
-
In: Optics Express. - 1094-4087 .- 1094-4087. ; 19:8, s. 7839-7846
-
Journal article (peer-reviewed)abstract
- We present the first experimental results for polarization-switched QPSK (PS-QPSK) and make a comparison with polarization-multiplexed QPSK. Our measurements confirm the predicted sensitivity advantage of PS-QPSK. We have also studied the single channel performance after transmission over 300 km and support the results with numerical simulations. It is shown that the two modulation formats have similar nonlinear tolerance and that optical dispersion compensation outperforms compensation with digital signal processing in the single channel case. Finally, we propose a novel transmitter for PS-QPSK based on an IQ modulator and two amplitude modulators driven in a push-pull configuration.
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| 17. |
- Sjödin, Martin E, 1983, et al.
(author)
-
Filter Optimization for Self-Homodyne Coherent WDM Systems using Interleaved Polarization Division Multiplexing
- 2011
-
In: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 29:9, s. 1219 - 1226
-
Journal article (peer-reviewed)abstract
- We examine the impact of filtering on self-homodynecoherent WDM systems using the interleaved polarization division multiplexing scheme. To investigate the performance limit and to provide more insight into previously obtained experimental results we perform numerical simulations in which different filter shapes and filter bandwidths are used. It is shown that with proper prefiltering of the data and filtering of the pilot tone in the receiver, performance can approach that of an intradyne system, which would make it possible to implement coherent systems with high spectral efficiency without any digitalsignal processing in the receiver.
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| 18. |
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| 19. |
- Sjödin, Martin E, 1983, et al.
(author)
-
Measurement of the Phase Noise Tracking Capability of a Digital Coherent Receiver
- 2011
-
In: European Conference and Exposition on Optical Communications, ECOC 2011; Geneva; Switzerland; 18 September 2011 through 22 September 2011. - 2162-2701. - 9781557529312
-
Conference paper (peer-reviewed)abstract
- We present a method to evaluate the phase noise tracking performance of a digital coherent receiver. Measurements of the phase error variance of QPSK at different symbol rates are presented for two different algorithms.
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| 20. |
- Tan, Ahmet Serdar, 1982, et al.
(author)
-
An ML-based Detector for Optical Communication in the Presence of Nonlinear Phase Noise
- 2011
-
In: IEEE International Conference on Communications. - : IEEE. - 1550-3607. - 9781612842332 ; , s. Art. no. 5962741-
-
Conference paper (peer-reviewed)abstract
- We present a closed-form maximum likelihood-based data detection algorithm for long-haul optical channels with dominant nonlinear phase noise induced by self-phase modulation. The closed-form detector is evaluated in terms of symbol error rate as a function of input power, and compared with other sub-optimal detectors as well as a non-parametric detector. We show that the performance of the detector deteriorates for high input power levels, resulting in an optimal operation region. We also provide insights into the behavior of the detector in the highly nonlinear regime.
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