新型双均匀光栅结构产生毫米波的光载无线通信下行链路

Radio Over Fiber Downlink System Based on a New Double-Uniform Fiber Bragg Grating Millimeter-Wave Generator

提出了一种全新的基于双均匀光纤光栅(UFBG)结构的毫米波产生方法,主要利用光纤光栅的滤波特性在中心站取得两束频率间隔为所需毫米波的光波,经差频后得到毫米波,并将其作为副载波。分析了经过0km,10km,30km,40km光纤传输后在基站接收端经过光电检测和相干解调滤波后得到的眼图。研究结果表明,该方法应用于光载无线通信(ROF)下行通信链路可获得比较理想的传输效果,且相同情况下,减小毫米波发生器中带通滤波器的带宽可以进一步改善系统的传输效果。

A new method is proposed to realize millimeter-wave sub-carrier generation at central station by using a double-uniform fiber Bragg grating filter （UFBG） scheme. Two optical waves with a spectrum of a millimeter-wave sub-carrier distance heterodyne after detector at base station then we can get the wanted millimeter-wave signal. The advantages of this new method of millimeter-wave sub-carrier generation are analyzed by designing a radio over fiber （ROF） downlink system,and the eye diagrams after detection and interference demodulation in 0 km,10 km,30 km,40 km transmission distance are also analyzed. Moreover,performance of this radio over fiber downlink system could be improved by reducing the bandwidth of band-pass filter of millimeter-wave sub-carrier generator. The proposed scheme may be taken as one of the candidates for the next generation high-speed and large-capability radio over fiber system.