Centralized lightwave radio-over-fiber system using only one phase modulator for optical millimeter-wave generation

We propose and demonstrate a novel radio-over-fiber (ROF) architecture by using only one phase modulator and one optical filter to generate an optical millimeter (mm) signal and realize wavelength reuse for upstream data connection. In the central office, the rf signals are generated by an electrical mixer that mixes the local oscillator (LO) and downstream data, and a phase modulator is used to generate an optical millimeter-wave signal. In the base station, an optical interleaver with two output ports is used to separate the optical carrier and the first-order sidebands. The separated first-order sidebands are used to generate optical millimeter-wave signals with a double LO frequency, while the separated optical carrier is reused for an uplink connection. There is no additional laser source for the upstream data generation in the base station and no dc-bias controller for phase modulator. By this method, we simplify the configuration of the radio-over-fiber system and reduce the cost of the system. (c) 2008 Society of Photo-Optical Instrumentation Engineers.