We demonstrate a bidirectional radio-over-fiber system based on optical coupling sing-sideband modulation, which can effectively reduce the impact of nonlinear distortion in transmission. With sidebands heterodyne detection, the system achieves 60-GHz wireless coverage. By optical carrier reusing, the base station can omit the laser source to make the system colorless. Through simulation analysis, the system has the credible transmission property both in downlink and uplink transmissions.
A flexible optical filter based on tunable arrayed waveguide grating (AWG) with triangular-like model electrodes is designed on lithium niobate-on-insulator. Using the electro-optic effect of lithium niobate, the 10 − 3 increase of the waveguides refractive index could be achieved with a 4.348-V effective external voltage. The tunable range of the central wavelength of AWG can reach 3.8 nm and the 3-dB bandwidth is about 0.43 nm.
As the best candidate for wireless-access networks, radio-over-fiber (RoF) technology can carry a variety of business. It is necessary to provide differentiated services for different users, so the network needs to produce signals with different modulation formats and different frequencies. A reconfigurable RoF system based on a switch and tunable optical filter that can realize modulation format conversion and multiple frequency signal switching functions is designed. It has a good performance in terms of bit error rate and an eye diagram. The design can help to use radio frequency resources efficiently and make dynamic bandwidth resources controllable.