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

本研究项目的目的是提出并研究一种新的用于高速无线通信的光纤无线电接入系统的可行性，该系统不需要任何外部电源设施。*利用所提出的光功率馈电技术，获得了15 mW的电功率和2V的电压。因此，可以成功地驱动包括低噪声放大器和光调制器在内的所有电/光组件。*基站采用电吸收调制器作为光调制器。利用馈电光功率提供的偏置实现了10dB的灵敏度提高。低噪声放大器的设计是在10 mW以下的小电源条件下进行的。利用光功率馈电的受激拉曼效应，在10公里长的光传输线上获得了大于2dB的光信号增益。最后，结合上述技术进行了系统实验，与现有的无功率系统相比，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.