Colorless beat interference cancellation receiver for the orthogonally polarized SSB-OOFDM signal with reduced guard band.

In the paper, we have proposed a novel optical orthogonal frequency division multiplexing (OOFDM) link scheme with the colorless beat interference cancellation receiver (BICR) structure for the single-sideband OOFDM (SSB-OOFDM) signal with an orthogonally polarized optical carrier and sideband, which is generated by using a polarization modulator and an optical band-pass filter. The BICR, employing only a polarization beam splitter and a balanced photodiode pair, can colorlessly mitigate the signal-signal beat interference (SSBI) induced by the square-law detection in a photodiode and thus the spectral efficiency (SE) is improved by reducing the guard band (GB) between the optical carrier and OOFDM signal. A simulation link for the 40  Gbit/s 16-QAM SSB-OOFDM signal with a reduced GB is built to demonstrate the feasibility of our proposed scheme. The simulation results indicate that the link has a higher SE compared to the conventional intensity modulation and direction detection scheme and the BICR exhibits a better performance in suppressing SSBI according to the error vector magnitude and the constellation diagrams.