Abstract
This paper considers the transmission of information over integrable泭 channels , a class of (mainly nonlinear )泭 channels 泭described by a Lax operator-pair. For such泭 channels , the泭 nonlinear 泭 Fourier transform , a powerful tool in soliton theory and exactly solvable models, plays the same role in diagonalizing the泭 channel 泭that the ordinary泭 Fourier 泭 transform 泭plays for linear convolutional channels . A transmission strategy encoding information in the泭 nonlinear 泭 Fourier 泭spectrum, termed nonlinear 泭frequency-division multiplexing, is proposed for integrable泭 channels 泭that is the泭 nonlinear analogue of orthogonal frequency-division multiplexing commonly used in linear泭 channels . A central and motivating example is fiber-optic data transmission, for which the proposed transmission technique deals with both dispersion and nonlinearity directly and unconditionally without the need for dispersion or nonlinearity compensation methods.