Wang Yiqun, Pei Li, Li Jing, Li Yueqin
Appl Opt. 2017 Jun 10;56(17):4982-4989. doi: 10.1364/AO.56.004982.
A full-duplex radio-over-fiber system is proposed, which provides both the generation of a millimeter-wave (mm-wave) signal with tunable frequency multiplication factors (FMFs) and wavelength reuse for uplink data. A dual-driving Mach-Zehnder modulator and a phase modulator are cascaded to form an optical frequency comb. An acousto-optic tunable filter based on a uniform fiber Bragg grating (FBG-AOTF) is employed to select three target optical sidebands. Two symmetrical sidebands are chosen to generate mm waves with tunable FMFs up to 16, which can be adjusted by changing the frequency of the applied acoustic wave. The optical carrier is reused at the base station for uplink connection. FBG-AOTFs driven by two acoustic wave signals are experimentally fabricated and further applied in the proposed scheme. Results of the research indicate that the 2-Gbit/s data can be successfully transmitted over a 25-km single-mode fiber for bidirectional full-duplex channels with power penalty of less than 2.6 dB. The feasibility of the proposed scheme is verified by detailed simulations and partial experiments.
提出了一种全双工光纤无线系统，该系统既能生成具有可调倍频因子（FMF）的毫米波（mm-wave）信号，又能实现上行链路数据的波长复用。将双驱动马赫-曾德尔调制器和相位调制器级联以形成光频梳。采用基于均匀光纤布拉格光栅的声光可调滤波器（FBG-AOTF）来选择三个目标光边带。选择两个对称边带来生成可调FMF高达16的毫米波，可通过改变施加声波的频率来进行调整。光载波在基站被复用用于上行链路连接。实验制备了由两个声波信号驱动的FBG-AOTF，并将其进一步应用于所提出的方案中。研究结果表明，对于双向全双工信道，2 Gbit/s的数据能够在25 km的单模光纤上成功传输，功率代价小于2.6 dB。详细的仿真和部分实验验证了所提方案的可行性。
