Studies on radio on fiber assess system eliminating external electric power supply at base station

本研究计划的目的是提出并研究一种新型光纤无线接入系统的可行性，该系统用于高速无线通信，无需任何外部供电设施。得到了以下结果：*采用所提出的光功率馈送技术，可获得15mW的电功率和2V的电压。因此，发现所有的电子/光学元件，包括一个低噪声放大器和一个光调制器可以成功地驱动。*采用电吸收调制器作为基站的光调制器。利用输入光功率提供的电偏置，实现了10dB灵敏度的提高。*低噪声放大器是在10mW的小功率条件下设计的。单级增益可达14dB，双级增益可达22dB。*利用光功率馈送的受激拉曼效应，在10km长的光传输线上获得了大于2dB的光信号增益。因此，光功率馈送是光信号功率补偿的有效方法。最后，结合上述技术进行了系统实验，与现有无功率系统相比，灵敏度提高了22dB。

The purpose of this research program is to propose and study the feasibility of a new radio on fiber access system for high-speed wireless communication without any external electric power supply facilities.The following results were obtained.*With the proposed optical power feeding technique, the electrical power of 15mW and the electric voltage of 2V were obtained.Hence, it is found that all of the electronic/optical components, including a low-noise amplifier and an optical modulator could be successfully driven.*An electroabsorption modulator was employed as the optical modulator at the base station. 10dB sensitivity improvement was achieved with the electrical bias supplied by the fed optical power.*The low-noise amplifier was designed under the condition of small power supply up to 10mW. The maximum gain of 14dB for single-stage, or 22dB for dual-stage was obtained.*With the stimulated Raman effect by the optical power feeding, the optical signal gain more than 2dB was obtained for a 10Km-long optical transmission line. Hence the optical power feeding was found to be effective for optical signal power compensation.Finally, the system experiment was done with the integration of above techniques, which resulted in 22dB sensitivity improvement compared with the existing powerless systems.