Research On ROF Hybrid Broadband Access Technology

Since the user's requirements continue to increase and the wireless communication broadband is gradually consumed, radio-over-fiber technique has become a hotspot of current research, which combines the high-capacity of the optical networks with the flexibility of wireless communications. Recently, the wired and wireless hybrid access full-duplex ROF system has received extensive attention, while the generation of the hybrid signals, the full-duplex services and the simplified base station are the key to study. In this paper, through theoretical analysis and experimental simulation, the performance of the hybrid access ROF system is studied.Firstly, the methods to generate the hybrid signals are theoretically analyzed, and the proposed hybrid access ROF systems at home and abroad are comparatively analyzed. Secondly, the methods to generate high-frequency millimeter-wave signal on the single wavelength hybrid access ROF system are theoretically analyzed and through the optical communication software OptiSystem, two hybrid access full-duplex ROF systems are realized. In the two ROF schemes, one is based on frequency eightfold and the other is based on the frequency twelvefold to simultaneously modulate and transmit the millimeter-wave,microwave and baseband signals and for the uplink channels, the wavelength reuse technique is used to simplify the base station. Finally, a full-duplex wavelength interleaved DWDM hybrid access ROF system is studied. For the downlink, the wavelength interleaved multiple subcarriers are generated through a single modulator and the1Gb/s wireless data and2Gb/s wired data are loaded to the sidebands through a intensity modulator and a phase modulator. At the base station, a demultiplexer is used to achieve multi-channel demultiplexing and after20km fiber transmission, the power penalty of the baseband and60GHz millimeter-wave signal are less than0.5dB. For the uplink, the wavelength reuse technique is also used to simplify each base station and the multiplexed uplink signals transmit to the central station after20km fiber transmission, and the power penalty of each uplink signal is less than0.1dB.