Demonstration of Frequency-Domain Averaging Based Channel Estimation for 40-Gb/s CO-OFDM With High PMD

We experimentally demonstrate the intrasymbol frequency-domain averaging based channel estimation for a 40-Gb/s polarization-division-multiplexed coherent optical orthogonal frequency-division multiplexing signal with eight quadrature amplitude modulation under large polarization-mode dispersion, showing improved efficiency as compared to the time-domain averaging based scheme.