中文摘要：

在光纤无线电技术中，通过光外差产生毫米波具有结构简单、成本低的特点，但中心站一般需要使用相干光源。文章提出了一种改进的光外差法，系统分析和仿真试验表明，谊方法不仅可以避免使用相干光源，而且中心站和无线终端都无需配备毫米波本振。同时中心站采用单边带的信号调制，还可以有效降低光纤色散引起的毫米波信号的衰落。

英文摘要：

Optical heterodyne technology is widely used in radio over fiber system in generating millimeter waves because of its low price and simple structure, but center stations generally use coherent source to eliminate phase noise. In this paper, a modified optical heter- odyne method is proposed and system analysis and simulation experiments show that its adoption will relieve the center station of the need to use coherent source and both the center station and radio terminals of the need for local millimeter wave oscillation. Furthermore, using single band modulation in center stations will effectively reduce the fiber dispersion effect.