Nonlinear Distortion in Transmission of Higher Order Modulation Formats

Transmission performance of a range of modulation formats including differentially encoded binary-, quaternary-, 8-, and 16-phase-shift-keying (DBPSK, DQPSK, D8PSK, and D16PSK) as well as 8- and 16-quadrature amplitude modulation (D8QAM and D16QAM) over optically compensated and DCF-free links are compared. Four different pulse-shapes are considered in a single-channel environment and the relative impact of intrachannel nonlinearities and nonlinear phase noise are analyzed.