通过光电相位调制和光纤光栅滤波实现Radio over Fiber传输系统设计
A Bi-directional Radio-over-Fiber System Based on Electronically Optical Phase Modulation and Fiber Bragg Gating
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摘要: 提出并模拟证明了基于电光相位调制(PM)和布拉格光纤光栅(FBG)实现受抑光载波的双边带(DSBOCS, Double-Sideband with Optical Carrier Suppression)的双向Radio over Fiber (RoF) 传输系统网络设计方案。激光光源置于中心站,载有信息的光信号通过光纤到达基站后经FBG分成两路,其中一路是被接收的下行信号,另一路作为上行信号调制后返回中心站。通过FBG,其下行信号不但实现了受抑光载波的双边带使通信带宽加倍,而且上行信号作为光源通过电光强度调制,可有效地实现信息的上载。仿真结果表明,光源发射功率为3dBm,无光放大,在色散系数为20ps/nm/km,衰减系数为0.25 dB /km的单模光纤中传输,超高频RF信号的频率可达24GHz,系统码元传输速率可达2.5Gbit/s、传输距离50km以上。Abstract: we simulantly demonstrate a system scheme of generating and transmitting baseband and RF signal based on double-sideband with optical carrier suppression scheme to generate optical millimeter-wave signal via electronical-optical phase modulation (EO-PM) and FBG.. The network architecture with centralized light source at central station and with data remodulation using downstream wavelength received at a base station is an attractive solution for low-cost implementation of the upstream transmitter as it requires no light source and wavelength management at the base station. The electronically optical phase modulator is inexpensive and mature too. The downlink communicated bandwidth can be doubled to realize Ultra Width Band Ultra High Frequency (UHF) communication via phase modulation and FBG at the base station. And the other signal which is from FBG can be as uplink via amplitude modulation availably. The simulation results show that the bi-directional 2.5Gbit/s data and UHF microwave with 24GHz is successfully transmitted over 50km distance of a single-mode fiber with a dispersion of 20ps/nm/km, an attenuation of 0.25dB/km and a light source power of 3dBm.