The performance of dually polarized M-QAM and L-QPRS systems with crosstalk and differential phase shift

Cartwright, Kenneth V.; Kaminsky, Edit J.; Williamson, E.P.; Duvoisin, P.F.; Hsieh, S. Tonia

doi:10.1109/secon.1991.147917

Cited by 1 publication

(1 citation statement)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 1 illustrates the impact of in-band crosstalk on higher-order modulation formats; (a) and (b) show a 16-QAM signal constellation (open circles) onto which another 16-QAM constellation (filled circles) with the same phase (a) or with a 45º-rotation relative to the signal (b) is added as an interferer. Since the minimum distance between symbols is most strongly affected by the rotated interferer, we expect the strongest impact of crosstalk for that case [7]. Figure 1(c) shows numerical simulations of the crosstalk penalty in terms of the signal-to-noise ratio (SNR) per symbol required to achieve a bit-error ratio (BER) of 10 -3 for ideal, square 4-, 16-, 64-, and 256-QAM constellations, based on Monte Carlo simulations of 2 17 symbols.…”

Section: Introductionmentioning

confidence: 97%

Penalties from In-Band Crosstalk for Advanced Optical Modulation Formats

Winzer¹,

Gnauck²,

Konczykowska

et al. 2011

37th European Conference and Exposition on Optical Communications

157

View full text Add to dashboard Cite

We quantify, through simulations and experiments at 21.4 GBaud, the effect of in-band crosstalk on several advanced optical modulation formats, showing a 1-dB penalty at a bit-error ratio of 1×10 -3 from a crosstalk of -18 dB, -24 dB, and -32 dB for QPSK, 16-QAM, and 64-QAM, respectively. OCIS codes: (060.2360) Fiber optics links and subsystems; (060.4080) Modulation IntroductionCommercial 100-Gb/s transmission systems available and in development today are largely based on single-carrier 28-Gbaud polarization-division-multiplexed (PDM) quadrature phase-shift keying (QPSK). Such signals can be operated on a 50-GHz frequency grid in wavelength-division-multiplexed (WDM) systems (i.e., at a spectral efficiency, SE, of 2 b/s/Hz), while still providing spectral margin for several optical add/drop nodes. In order to further increase transport capacities, greater SEs can be achieved using higher-level quadrature amplitude modulation (QAM), such as 16-QAM and 64-QAM. The more severe impact of in-band crosstalk on these higherorder formats can represent an important limitation arising, e.g., from imperfect optical add/drop nodes or doubleRayleigh backscatter in Raman amplified systems [1,2]. In addition, in-band crosstalk represents a key limitation in the upcoming class of spatially multiplexed systems, where low-crosstalk multi-core fiber [3,4] is being designed to avoid complicated multiple-input multiple-output (MIMO) processing to counteract crosstalk [5,6]. In all of the above scenarios, it is important to know the crosstalk levels at which higher-order modulation formats start to suffer penalties. In this paper we quantify the increasing crosstalk penalties when increasing the constellation size in single-polarization QAM systems, using simulations and 21.4-GBaud QPSK, 16-QAM, and 64-QAM experiments.

show abstract

Section: Introductionmentioning

confidence: 97%