A Radio-Over-Fiber（ROF） communication system is given and analyzed

in which Four-Wave Mixing（FWM） is used to generate sideband and transmit baseband signals.Two pairs of optical carrier suppression sidebands are generated in its central station

one transmits the downlink signals and the other carries the baseband signals and transmits the uplink signals at the base station.The system spectrum and Bit Error Ratio（BER） curve obtained by simulation indicate that when the baseband signals are coupled

the energy penalty of the downlink signals remains unchanged

while the baseband and uplink signals have better dispersion resistance.