Error Probability of DPSK Signals With Cross-Phase Modulation Induced Nonlinear Phase Noise

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan
IEEE Journal of Selected Topics in Quantum Electronics (Impact Factor: 2.83). 04/2004; 10(2):421 - 427. DOI: 10.1109/JSTQE.2004.826574
Source: IEEE Xplore


The error probability is derived analytically for differential phase-shift keying (DPSK) signals contaminated by both self- and cross-phase modulation (SPM and XPM)-induced nonlinear phase noise. XPM-induced nonlinear phase noise is modeled as Gaussian distributed phase noise. When fiber dispersion is compensated perfectly in each fiber span, XPM-induced nonlinear phase is summed coherently span after span and is the dominant nonlinear phase noise for typical wavelength-division-multiplexed (WDM) DPSK systems. For systems without or with XPM-suppressed dispersion compensation, SPM-induced nonlinear phase noise is usually the dominant nonlinear phase noise. With longer walkoff length, for the same mean nonlinear phase shift, 10-Gb/s systems are more sensitive to XPM-induced nonlinear phase noise than 40-Gb/s systems.

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Available from: Keang-Po Ho, Dec 18, 2012
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    • "The SNR penalty is calculated by expanding the phase distribution of Gaussian noise as a Fourier series [16, App. 4.A], similar to both [9], [13]. With an independently optimized launched power, the equivalent SNR of the QPSK channel is assumed to be 10 dB, for an error probability of about 10 −3 . "
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    ABSTRACT: For 100-Gb/s quadriphase-shift keying (QPSK) signal with on-off keying (OOK) signal in neighboring wavelength-division-multiplexed (WDM) channel, the smoothing filter in the feedforward phase estimation scheme must be optimized to minimize the phase error. With optimal Wiener filter, typical 0-dBm launched power 10-Gb/s OOK signals give a SNR penalty of 0.66 and 0.30 dB for standard single-mode and nonzero dispersion-shifted fibers, respectively. Comment: 6 pages, 3 figures
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    • "For each OOK pump at spectral distance from probe, the number of (independent) symbols that predominantly contribute to the induced XPM at a specific sampling time on the probe is related to both the uncompensated per-span walkoff accumulated by the pump over one effective length along the transmission fiber [10], normalized by the OOK symbol time , and to the (normalized) per-span average walkoff after in-line compensa- tion , where [ps/nm] is the in-line dispersion per span. A little thought about the sawtooth sliding movement of the pump channel relative to the probe channel reveals that the number of interfering bits for each pump for time-asynchronous WDM channels over spans is For zero walkoff, since only one pump bit generates XPM on the probe at a specific sampling time. "
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    ABSTRACT: In this paper we show that, in hybrid wavelength division multiplexed systems, the performance of high datatrate QPSK channels impaired by cross-phase modulation (XPM) induced by the lower rate OOK channels can be simply estimated by an extension of a well-known linear model for XPM, and novel analytical expressions of the sensitivity penalty are provided. From such a model we prove that the reported QPSK penalty decrease with QPSK baud rate increase should be attributed to the action of the phase estimation process rather than to the walkoff effect. The model also simply shows how coherent QPSK is more affected by XPM than incoherent DQPSK, and allows to infer that even more impact is expected when the baudrate is further reduced through polarization multiplexing.
    Journal of Lightwave Technology 10/2009; 27(18-27):3974 - 3983. DOI:10.1109/JLT.2009.2021537 · 2.97 Impact Factor
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    • "However, no analytical study has been undertaken to better understand the statistical properties of IFWM for phase-modulated systems. In addition, it has been known for some time that in PSK or DPSK systems at symbol rates above 10 GSym/s, intrachannel nonlinearities dominate over interchannel effects such as cross-phase modulation (XPM) [22] and therefore IFWM is a more fundamental problem that needs to be addressed. "
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    ABSTRACT: We have analytically derived the correlation functions of intrachannel four-wave mixing (IFWM)-induced phase and amplitude noises in phase-modulated optical communication systems. The phase and amplitude noises are correlated with each other for binary phase-shift keying (PSK) systems but uncorrelated for $M$ -ary PSK systems with $M>2$ . We have also derived analytical approximations to the probability distribution of IFWM-induced phase noise for PSK and differential PSK systems. Furthermore, we have studied the performance of an optimal linear phase-noise predictor derived from the IFWM-induced phase-noise autocorrelation function. This yields a performance improvement of 1.8 dB when IFWM-induced phase noise is the dominant impairment, and an improvement of 0.8 to 1.2 dB in the presence of amplified spontaneous emission noise and nonlinear phase noise in typical terrestrial links.
    Journal of Lightwave Technology 08/2008; 26(14):2128-2135. DOI:10.1109/JLT.2008.923227 · 2.97 Impact Factor
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