Optical Signal-to-Noise Ratio Monitoring Using Uncorrelated Signal-Spontaneous Beat Noise

摘要: Abstract—Optical performance monitoring is essential formanaging both current and future optical networks. One im-portant quantity to monitor the signal-to-noiseratio(OSNR). Traditional spectrum analyzer (OSA) basedmeasurements become problematic in dynamically reconfigur ablewavelength-division multiplexing (WDM) We prop osea new method based on analyzing uncorrelated signal-spontaneous beat noise show through simulation that theOSNR range from 10 dB 25 dB, OSNR estimation errorcan be less than 0.6 dB. I. INTRODUCTIONInterest (OPM) first tookhold early 1990s with introduction of Wavelength-Division Multiplexing systems. As people began tothink more about networks rather trans-mission systems, it became clear a solution would beneeded for problem [1]. WDM networkshave enabled rapid growth data traffic networkbackbone. Further increases capacity can gained bymoving dense wavelength division (DWDM)with large channel counts. Optical isessential managing such high transmissionand switching systems monitoringdescribes an extremely wide functionality intendedto included communication network improve thenetwork’s [2]. Both WDMor DWDM require reliable economicalmethods without interrupting theclient connections. For efficient operation mainten anceof network, various parametersincluding wavelength, power, signal-to-noise ratio (OSNR), paths, etc. [3].The widespread use amplifiers has long-haul [4], but cascadingof number introducesamplified spontaneous emission (ASE) into opticalsignals which degrades significantfactor quality moni-toring monitoring. Forexample, necessary fault managementincluding localization diagnosis. In order localizeOSNR degradation faults, operators multipletruck rolls along entire length segments.In ultra-long-haul networks, diagnosing these faults withoutOSNR may challenging add-dropmultiplexers (OADMs) complicate situation further [5].Quite few techniques have been developed monitorOSNR. Current Monitoring Techniques classi-fied two groups. by measuringthe ASE outside bandwidth. To simplifythe name, we call this group out-of-bandOSNR The other mea-suring inside bandwidth iscalled in-band or in-channel Out-of-bandOSNR includes traditional an-alyzer [6], [7] some tech-niques using arrayed waveguide grating (AWG) circuits [8]–[10]. basedOSNR relies interpolation levelsadjacent interest obtain approximateASE level channel. interpolated maynot real channels interest, thoseconventional linear not monitorthe accurately reconfigurable WDMnetwork. This because reconfigurableWDM each traverse differentroute different EDFA’s so hasunflat spectrum. principle usingarrayed [8]–[10] was alsobased measuring between channels, theAWG precisely measure inpresence multi-path interference effects OADM/OXC(Optical Cross Connect) networking Polarization nullingmethod [11]–[14] one ap-proaches. But its limited ModeDispersion (PMD). Even if PMD compensated,polarization scattering ultra results infast bit-to-bit polarization fluctuations are impractical totrack [1], [15]. addition, speed monitoringwill controller. Another in-bandOSNR approach low frequency noisemeasurement [16]. simple implement