Offset-QAM multicarrier technology for optical systems and networks (Invited)

Abstract

In this paper, we review the multicarrier technology using offset quadrature amplitude modulation (QAM) for optical communication systems and networks. We investigate the orthogonality condition of this technology and discuss its electronic and optical domain implementation. It is shown that discrete-Fourier-transform based offset-QAM orthogonal frequency division multiplexing (OFDM) can greatly relax the required length of guard interval for dispersion compensation compared to conventional OFDM, and reduce the implementation complexity compared to Nyquist FDM. Optically-multiplexed offset-QAM super-channels exhibit improved performance, and relaxed device specifications for minimizing inter-channel crosstalk compared to all-optical OFDM and Nyquist WDM.