We propose and experimentally demonstrate a novel in-band optical signal-to-noise ratio (OSNR) monitoring technique that uses a commercially available widely tunable optical bandpass filter to sample the measured optical power as input features of Gaussian process regression (GPR) can accurately estimate the large dynamic range OSNR and is not affected by the configuration of the optical link, and has the characteristics of distributed and low cost. Experimental results for 32 Gbaud PDM-16QAM signals demonstrate OSNR monitoring with the root mean squared error (RMSE) of 0.429 dB and the mean absolute error (MAE) of 0.294 dB within a large OSNR range of -1 dB~30 dB. Moreover, our proposed technique is proved to be insensitive to chromatic dispersion, polarization mode dispersion, nonlinear effect, and cascaded filtering effect (CFE). Furthermore, our proposed technique has the potential to be employed for link monitoring at the intermediation nodes without knowing the transmission information and is more convenient to operate because no calibration is required.
A novel optical signal-to-noise ratio monitoring technique based on Gaussian process regression
First published at:Jan 15, 2021
 Xue D J, Yu S H, Yang Q, et al. Frontier research of ultra-high-speed ultra-large-capacity and ultra-long-haul optical transmission[J]. Front Optoelectron, 2016, 9(2): 123–137.
 Cartledge J C. Performance of coherent optical fiber transmission systems[J]. Front Optoelectron, 2018, 11(2): 128–133.
 Zhang P, Feng Q G, Li W, et al. Simultaneous OTDR dynamic range and spatial resolution enhancement by digital LFM pulse and short-time FrFT[J]. Appl Sci, 2019, 9(4): 668.
 Savory S J. Digital coherent optical receivers: algorithms and subsystems[J]. IEEE J Sel Top Quantum Electron, 2010, 16(5): 1164–1179.
 Downie J D, Hurley J, Pikula D, et al. Ultra-long-haul 112 Gb/s PM-QPSK transmission systems using longer spans and Raman amplification[J]. Opt Express, 2012, 20(9): 10353–10358.
 Khan F N, Zhong K P, Zhou X, et al. Joint OSNR monitoring and modulation format identification in digital coherent receivers using deep neural networks[J]. Opt Express, 2017, 25(15): 17767–17776.
 Zhang L, Zhang X G, Xi L X, et al. Modified optical-signal-noise-ratio monitoring method based on high order statistical moment in PM-QPSK coherent optical system[J]. Chin. J. Lasers, 2014, 41(5): 0505004.
张磊, 张晓光, 席丽霞, 等. PM-QPSK相干光通信系统中基于高阶统计矩的光信噪比监测方法的修正[J]. 中国激光, 2014, 41(5): 0505004.
 Schmogrow R, Nebendahl B, Winter M, et al. Error vector magnitude as a performance measure for advanced modulation formats[J]. IEEE Photonics Technol Lett, 2012, 24(1): 61–63.
 Lundberg L, Sunnerud H, Johannisson P. In-band OSNR monitoring of PM-QPSK using the Stokes parameters[C]//Proceedings of 2015 Optical Fiber Communications Conference and Exhibition, Los Angeles, 2015.
 Dong Z H, Lau A P T, Lu C. OSNR monitoring for QPSK and 16-QAM systems in presence of fiber nonlinearities for digital coherent receivers[J]. Opt Express, 2012, 20(17): 19520–19534.
 Hu C J, Li W, Feng Q G, et al. A novel in-band OSNR monitoring technique based on fractional Fourier transform of LFM signal[J]. Opt Commun, 2019, 445: 36–40.
 Lee J H, Choi H Y, Shin S K, et al. A review of the polarization-nulling technique for monitoring optical-signal-to-noise ratio in dynamic WDM networks[J]. J Lightwave Technol, 2006, 24(11): 4162–4171.
 Tao Z N, Chen Z Y, Fu L B, et al. Monitoring of OSNR by using a Mach–Zehnder interferometer[J]. Microw Opt Technol Lett, 2001, 30(1): 63–65.
 Shen S K, Yang A Y, Sun Y N. Improved off-center narrow filter method to monitor in-band optical signal-to-noise ratio[J]. Acta Opt Sin, 2009, 29(S2): 74–78.
沈世奎, 杨爱英, 孙雨南. 窄带离心滤波准确测量带内光信噪比的修正方法[J]. 光学学报, 2009, 29(S2): 74–78.
 Hu C J, Li W, Zheng H, et al. A novel cost-effective and distributed in-band OSNR monitoring method using Gaussian process regression[J]. IEEE Photonics J, 2019, 11(4): 7204312.
 Oda S, Yang J Y, Akasaka Y, et al. In-band OSNR monitor using an optical bandpass filter and optical power measurements for superchannel signals[C]//Proceedings of the 39th European Conference and Exhibition on Optical Communication (ECOC 2013), London, 2013.
 Dong Z H, Zhong K P, Zhou X, et al. Modulation-format-independent OSNR monitoring insensitive to cascaded filtering effects by low-cost coherent receptions and RF power measurements[J]. Opt Express, 2015, 23(12): 15971–15982.
 Yin G, Cui S, Ke C J, et al. Reference optical spectrum based in-band OSNR monitoring method for EDFA amplified multispan optical fiber transmission system with cascaded filtering effect[J]. IEEE Photonics J, 2018, 10(3): 7201910.
 Lai J S, Yang A Y, Sun Y N. Optical fiber communication performance monitoring based on asynchronous delay tap sampling[J]. Acta Opt Sin, 2012, 32(11): 1106004.
赖俊森, 杨爱英, 孙雨南. 基于异步延迟采样的光通信性能监测方法[J]. 光学学报, 2012, 32(11): 1106004.
 Meng F, Yan S, Nikolovgenis K, et al. Field trial of Gaussian process learning of function-agnostic channel performance under uncertainty[C]//Proceedings of 2018 Optical Fiber Communications Conference and Exposition (OFC), San Diego, 2018.
National Key Research and Development Program of China (2018YFB2200900)
Get Citation: Yan Ran, Hu Chunjie, Li Wei. A novel optical signal-to-noise ratio monitoring technique based on Gaussian process regression[J]. Opto-Electronic Engineering, 2021, 48(1): 200077.