毫米波光纤（ROF）传输系统中当采用强度调制器直接调制毫米波信号时,随着传播距离的延长会产生信号强度的周期性衰落问题,限制了毫米波通信技术的发展。光学倍乘法（OFM）将低频或中频调制信号搭载在扫频光信号上,通过在基站生成毫米波的方法,有效缓解信号强度的周期性衰落,具有广阔的发展前景。提出并实验研究了一种基于光学倍乘法产生光毫米波的全双工毫米波光纤传输系统。系统中利用光纤Bragg光栅提取光波作为上行链路光载波,基站中不需配置光源,而且对光功率的损耗小,合理利用了资源。基站中还采用低频本振与毫米波载波混频的方法实现上行链路本振,解决了上行链路本振的生成难题,方法简单,成本低廉,有利于简化基站,降低成本。

Radio over fiber (ROF) systems which employ intensity modulation with direct modulator are faced with severe chromatic dispersion-induced fading of the remotely delivered RF signals, which limits the development of millimeter-wave communications technology. Optical frequency multiplication (OFM) carry low frequency or intermediate frequency modulated signals on optical signals. The base station generates millimeter-wave signals, which effectively combatted the problem of chromatic dispersion-induced fading. This method has broad development prospects. The design of a bi-directional radio over fiber transmission system based on OFM is proposed and experimental studied. In the system, a fiber Bragg grating is used to extract light wave as a light-uplink carrier. The base station needing no light source. The loss of optical power is low, the use of resources is rational. At the base stations, low-frequency oscillator and millimeter-wave carrier are mixed to gain the uplink oscillator, which solve the problem of uplink generation. This method simplifies the system and lowers the cost.