Characteristics Investigation of High-Speed Multi-Carrier Transmission Using MIMO-Based Crosstalk Compensation in Homodyne Detection Scheme

We experimentally investigate the characteristics of a multi-carrier optical transmission system with neighboring-crosstalk compensation using multiple-input multiple-output processing as an integrated part of a polarization-demultiplexing stage in a homodyne detection scheme for high-speed optical signals. We show that the crosstalk compensation yields adequate performance in the presence of high polarization mode dispersion and high-speed changes in the state of polarization. We also clarify the performance required of local oscillators in the receivers for adequate crosstalk compensation in this scheme. Furthermore, we show the applicability of the system equipped with delay compensation to long-haul transmission through 480-km WDM transmission experiments employing 256-Gb/s optical multi-carrier signals with the subcarrier spacing of 25 GHz, which corresponds to 78% of the signal baud rate.