Stokes Space-Based Modulation Format Recognition for Autonomous Optical Receivers

We propose a new modulation format recognition method for optical links employing OOK, M-PSK, M-PAM, and M-QAM modulation formats. The method combines the Stokes space analysis and higher order statistics as a part of a universal digital coherent receiver. Experimental investigation demonstrates successful format recognition of single-carrier optical signals modulated at 31.5 GBd with OOK, BPSK, QPSK, or 16QAM, and transported through 810 km of large area fiber. These results enable the development of autonomous receivers capable of identifying and demodulating unknown signals from noncooperating transmitters, including legacy optical transmitters.