A hardware-efficient OSNR monitor employing Higuchi fractal dimension on directly detected optical signals

Optical Signal-to-Noise Ratio (OSNR) is a critical performance metric in optical transmission networks (OTNs), as it directly correlates with the bit error rate (BER), thereby influencing system reliability and efficiency. In this paper, we propose a novel, hardware-efficient OSNR monitoring technique based on the Higuchi fractal dimension algorithm applied to directly received optical signals. Simulation results demonstrate that the proposed method achieves a root mean square error (RMSE) of 0.75 dB within an OSNR range of 14–34 dB for 50 Gbaud DP-16QAM signals.