Abstract: The disclosed systems and methods for monitoring, by a coherent optical monitor (OPM), generalized optical signal-to-noise ratio (gOSNR) of an optical channel, the method comprising: i) receiving, by an input port of the coherent OPM, a first signal and a second signal, wherein: the first signal and the second signal include same data, the first signal is an optical signal received from the optical channel, and the first signal is affected by a noise; ii) processing, by a digital signal processor (DSP) of the coherent OPM, the first signal and the second signal and extract the data from the first signal and the second signal; iii) computing, by the DSP, a first correlation between the data from the first signal and the data from the second digital signal; and iv) computing, by the DSP, a first gOSNR based on the first correlation.

Abstract: The disclosed systems and methods for monitoring, by a coherent optical monitor (OPM), generalized optical signal-to-noise ratio (gOSNR) of an optical channel, the method comprising: i) receiving, by an input port of the coherent OPM, a first signal and a second signal, wherein: the first signal and the second signal include same data, the first signal is an optical signal received from the optical channel, and the first signal is affected by a noise; ii) processing, by a digital signal processor (DSP) of the coherent OPM, the first signal and the second signal and extract the data from the first signal and the second signal; iii) computing, by the DSP, a first correlation between the data from the first signal and the data from the second digital signal; and iv) computing, by the DSP, a first gOSNR based on the first correlation.

Abstract: The disclosed systems and methods for optical filter fault localization. The optical filter fault localization is based on: i) determining an accumulated noise density at frequencies where ASE noise is filtered out by a faulty optical filter in an optical signal; ii) comparing the accumulated noise density with predicted accumulated noise densities, the predicted accumulated noise densities representing noises predicted from a plurality of optical filters to a receiver; and iii) determining, based on the comparison of the accumulated noise density and the predicted accumulated noise densities, a location of the faulty optical filter.

Abstract: Systems and methods for longitudinal performance monitoring of an optical communication line communicably connecting a transmitting device to a receiving device for transmitting a signal therebetween. The method comprises receiving the signal at the receiving device, the signal having been affected by propagative impairments accumulated along the optical communication line, generating, at the receiving device, a linear signal based on the received signal, generating, based on the linear signal, a plurality of signal templates, and determining correlation values between the received signal and each signal template of the plurality of signal templates, each correlation value being indicative of a local longitudinal performance of the optical communication line.