WDM–OFDM–RoF system based on optical coupling tandem single-sideband modulation

The authors report on a WDM–OFDM–RoF system based on a novel optical coupling tandem single-sideband (O-TSSB) transmitter for one wavelength carrying two radio frequency signals. The impact of nonlinear distortion consisting of harmonic distortion and intermodulation distortion in this system is theoretically investigated and it has been found that the O-TSSB transmitter can reduce the nonlinear distortion effectively. Transmission over 25 and 50 km of standard single mode fiber is successfully demonstrated and it indicates that the modulation index 0.6 is more adapted to O-TSSB transmitter. The error vector magnitude of the system based on O-TSSB transmitter after transmission over 25 km is <\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$<$$\end{document}0.05, relative to the traditional electric coupling tandem single-sideband transmitter. For O-TSSB transmitter, all channels after 25 km transmission achieve performance below the 10-3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$10^{-3}$$\end{document} forward error correction limit.