TY - JOUR

T1 - Nonlinear Spectrum of Conventional OFDM and WDM Return-to-Zero Signals in Nonlinear Channel

AU - Турицын, Сергей Константинович

AU - Седов, Егор Валентинович

AU - Редюк, Алексей Александрович

AU - Федорук, Михаил Петрович

PY - 2020/1/15

Y1 - 2020/1/15

N2 - The nonlinear Schrodinger equation (NLSE) is often used as a master path-average model for fiber-optic links to analyse fundamental properties of such nonlinear communication channels. Transmission of signal in nonlinear channels is conceptually different from linear communications. We use here the NLSE channel model to explain and illustrate some new unusual features introduced by nonlinearity. In general, NLSE describes the co-existence of dispersive (continuous) waves and localised (here in time) waves - soliton pulses. The nonlinear Fourier transform method allows one to compute for any given temporal signal the so-called nonlinear spectrum, that defines both continuous spectrum (analogue to conventional Fourier spectral presentation) and solitonic components. Nonlinear spectrum remains invariant during signal evolution in the NLSE channel. We examine conventional orthogonal frequency-division multiplexing (OFDM) and wavelength-division multiplexing (WDM) return-to-zero signals and demonstrate that both signals at certain power levels have soliton component. We would like to stress that this effect is completely different from the soliton communications studied in the past. Applying Zakharov-Shabat spectral problem to a single WDM or OFDM symbol with multiple sub-carriers we quantify the effect of statistical occurrence of discrete eigenvalues in such an information-bearing optical signal. Moreover, we observe that at signal powers optimal for transmission an OFDM symbol with high probability has a soliton component.

AB - The nonlinear Schrodinger equation (NLSE) is often used as a master path-average model for fiber-optic links to analyse fundamental properties of such nonlinear communication channels. Transmission of signal in nonlinear channels is conceptually different from linear communications. We use here the NLSE channel model to explain and illustrate some new unusual features introduced by nonlinearity. In general, NLSE describes the co-existence of dispersive (continuous) waves and localised (here in time) waves - soliton pulses. The nonlinear Fourier transform method allows one to compute for any given temporal signal the so-called nonlinear spectrum, that defines both continuous spectrum (analogue to conventional Fourier spectral presentation) and solitonic components. Nonlinear spectrum remains invariant during signal evolution in the NLSE channel. We examine conventional orthogonal frequency-division multiplexing (OFDM) and wavelength-division multiplexing (WDM) return-to-zero signals and demonstrate that both signals at certain power levels have soliton component. We would like to stress that this effect is completely different from the soliton communications studied in the past. Applying Zakharov-Shabat spectral problem to a single WDM or OFDM symbol with multiple sub-carriers we quantify the effect of statistical occurrence of discrete eigenvalues in such an information-bearing optical signal. Moreover, we observe that at signal powers optimal for transmission an OFDM symbol with high probability has a soliton component.

KW - Communication system nonlinearities

KW - nonlinear optics

KW - optical fiber communication

KW - optical solitons

KW - signal analysis

KW - simulation

KW - subcarrier multiplexing

KW - transmission line theory

KW - wavelength division multiplexing

KW - OFDM

KW - COMPENSATION

KW - Optical solitons

KW - Optical pulses

KW - EIGENVALUES

KW - Modulation

KW - TRANSFORM

KW - COMPUTATION

KW - Mathematical model

KW - Nonlinear optics

KW - SOLITON

UR - http://www.scopus.com/inward/record.url?scp=85078701574&partnerID=8YFLogxK

U2 - 10.1109/JLT.2019.2956236

DO - 10.1109/JLT.2019.2956236

M3 - Article

AN - SCOPUS:85078701574

VL - 38

SP - 352

EP - 358

JO - Journal of Lightwave Technology

JF - Journal of Lightwave Technology

SN - 0733-8724

IS - 2

M1 - 8915744

ER -