Simple and Robust Chromatic Dispersion Estimation for RGI-CO-OFDM Systems

Because of the variations of transmission route and environment, reduced-guard interval coherent optical orthogonal frequency-division multiplexing (RGI-CO-OFDM) has difficulty removing chromatic dispersion (CD) accurately by the use of over-lapped frequency domain equalizer (OFDE) according to the predicted CD value. To make RGI-CO-OFDM systems adaptive to CD change without extra cyclic prefix (CP) overhead, an effective CD estimation (CDE) algorithm is proposed to calibrate the CD compensation value of OFDE. The detailed simulation results prove the excellent abilities of the proposed CDE algorithm to resist inter-symbol interference and suppress amplified spontaneous emission noise. Comparing with the traditional RGI-CO-OFDM systems, its tolerable dynamic CD range can be increased >30 times at the same training symbols and CP overheads at the transmission rate of 480 Gb/s.