LAUSR

Abstract In this work, we have proposed and verified a low-complexity optical signal-to-noise ratio (OSNR) monitoring scheme based on amplitude variance analysis (AVA). The key feature for OSNR monitoring is extracted from the variance between the received symbols and the corresponding ideal amplitude circles. The simulation results have demonstrated that the obtained mean absolute errors (MAEs) of OSNR monitoring achieve 0.1176 dB, 0.2064 dB, 0.2179 dB, 0.2249 dB, and 0.2631 dB for 28 GBaud polarization-division-multiplexing (PDM) quadrature-phase-shift-keying (QPSK), PDM-8-quadrature-amplitude-modulation (QAM), PDM-16QAM, PDM-32QAM and PDM-64QAM, respectively. Meanwhile, the proposed AVA scheme presents good tolerances to chromatic dispersion (CD) and polarization-mode dispersion (PMD). Furthermore, the OSNR monitoring performances have been verified by a 28 GBaud PDM-QPSK/8QAM/16QAM/32QAM experimental transmission system. The obtained MAEs are 0.1293 dB, 0.3105 dB, 0.3214 dB, and 0.3823 dB, respectively. Compared with the moment estimation (MEB) and deep-neural-network (DNN)-based schemes, the accuracy of the proposed AVA scheme has been improved and its computation complexity is well reduced.