Stanislav DEREVYANKO  (Ben Gurion University of the Negev)

Channel models and spectral efficiency limits for optical fiber transmission systems employing the Nonlinear Fourier Transform

In this talk I will outline recent developments in the field of theoretical modelling of NFT-channels limited by the amplifier spontaneous emission. The two main problems currently facing NFT-based transmission are signal-noise interaction due to the loss of integrability and low spectral efficiency due to the need for the burst mode transmission. With respect to the former I will show that the sources of signal distortion at the receiver are twofold: a direct ASE noise component and the so-called processing noise of purely deterministic nature. For the popular b-modulation NFT scheme the developed theory of the ASE noise component shows that the noise power spectral density goes to zero at high values of input power so the dominating signal distortion at high power is the processing noise.
With regard to the ways of increasing the spectral efficiency I will show that by using more efficient nonlinear spectral carriers (like Gauss-Hermit waveforms) one can significantly improve the time-bandwidth product of the NFT bursts and reach spectral efficiencies that are competitive with the conventional values at the same propagation distances.