Analytical Modeling of Nonlinear Propagation in Uncompensated Optical Transmission Links

Abstract

We present analytical results on the impact of nonlinear propagation in uncompensated links. We test the accuracy of our model in the context of ultradense wavelength-division-multiplexing polarization-multiplexed quadrature phase-shift keying (PM-QPSK) systems, at the Nyquist spectral efficiency limit. We show that the predicted system performance matches simulation results very accurately over a broad range of system scenarios. A simple closed-form analytical formula provides an effective tool for the quick and accurate prediction of system performance. IndexTerms-Dense wavelength-division multiplexing (DWDM), Nyquist wavelength-division multiplexing (WDM), optical transmission, polarization-multiplexed quadrature amplitude modulation (PM-QAM), polarization-multiplexed quadrature phase-shift keying (PM-QPSK), uncompensated systems.

Experimental characterisation of digital Nyquist pulse-shaped dual-polarisation 16QAM WDM transmission and comparison with the Gaussian noise model of nonlinear propagation

“…Expressions for the power spectral density (PSD) of the FWM-induced noise in Nyquist-limited WDM transmission are derived in [9]- [11]. The expression below gives the NLI noise PSD [9] 2 km -1 is the fibre group velocity dispersion, and the optical bandwidth of the signal B = 70.1 GHz.…”

“…Expressions for the power spectral density (PSD) of the FWM-induced noise in Nyquist-limited WDM transmission are derived in [9]- [11]. The expression below gives the NLI noise PSD [9] 2 km -1 is the fibre group velocity dispersion, and the optical bandwidth of the signal B = 70.1 GHz. The resulting FWM-induced noise power, P NLI = I NLI  is added to the ASE noise power, calculated using the EDFA noise figure of 4.5 dB, to obtain the OSNR, which, from the back-to-back BER curve in Figure 2, is used to calculate bit error ratio.…”

Nonlinear Shannon Limit in Optical Fiber Transmission System

“…Therefore in addition to the Shannon limit, practical channel capacity is believed to be limited by nonlinear Shannon limit [5]- [17]. The nonlinear Shannon limit has been derived under the assumption that the received signal points on the constellation map deviated by optical amplifier noise and nonlinear interference noise is assumed to be symmetrically distributed around the ideal signal point and the sum of the noises are regarded as white Gaussian noise.…”

Analysis of Nonlinear Signal Interference to Optimize the Coherent Optical Transmission System

“…Moreover, the commercial optical simulator software is expensive and simulation running output takes longer time [6]. Consequently, GN model is the way and method to determine the power of nonlinear signal interference ( NLSI p ) [7][8][9]. In GN model, we control the total number of spans causing variation to the link length randomly [10].…”