5 Gbit/s Full-Duplex Radio-Over-Fiber Link With Optical Millimeter-Wave Generation by Quadrupling the Frequency of the Electrical RF Carrier

A scheme to implement the full-duplex radio-over-fiber (RoF) link by quadrupling the frequency of the electrical RF carrier without a lightwave source at the remote base station (RBS) is proposed. Not only does the scheme reduce the complexity of the RBS and its frequency requirement for the devices, but the generated optical millimeter-wave (mm-wave) signal also has good transmission performance because both the fading effect and the bit walk-off effect caused by fiber dispersion are avoided. A 5 Gbit/s full duplex RoF simulation link with a 40 GHz optical mm-wave signal is built. It shows that the eye diagrams of both the uplink and downlink signals remain open and clear even after the signals are transmitted over 60 km standard single-mode fibers. The simulation results agree well with our theoretical prediction.