Pilot-Aided Optical Signal-to-Noise Ratio Estimation for Direct-Detection OFDM Systems

Abstract

We propose an optical signal-to-noise ratio (OSNR) estimation method for direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) systems by calculating the electrical SNR of one pilot subcarrier based on correlation. Simulation and experiment are conducted to verify this OSNR estimation method in a 15-Gb/s DDO-OFDM system. The maximum OSNR estimation error is 0.8 dB within an OSNR range of 8-28 dB for 100- and 200-km transmission distances.