| 引用本文: | 孙家可,杜科.面向配电网通信的光载无线系统线性度的研究[J].电力系统保护与控制,2017,45(1):118-124.[点击复制] |
| SUN Jiake,DU Ke.Research on the linearity of radio-over-fiber system for distribution network communication[J].Power System Protection and Control,2017,45(1):118-124[点击复制] |
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| 摘要: |
| 光载无线(RoF)通信技术中的光电转换非线性问题限制了RoF系统传输信号的功率。为降低这种非线性，在前人研究的基础上，探讨了如何能够有效抑制由于调制器本身产生的非线性引起的三阶交调失真，从而获得更好的线性度。首先，提出了实现RoF结构的基本方案，由于调制器严重的非线性，系统的线性度十分不理想，最终获得的无杂散动态范围(SFDR)仅能达到111.32 dB.Hz2/3。随后，在基本方案的基础上提出了改进方案。此方案增加了一个马赫-曾德尔调制器和一个移相器以产生一个未调制的光载波信号，目的是使此信号产生的三阶交调项在移相器的作用下实现与被调制光信号产生的三阶产物相抵消，以提高系统的线性度。在改进后的方案下，最终得到的无杂散动态范围(SFDR)能够达到121.8 dB.Hz2/3，比基本方案的SFDR提高了10.48 dB.Hz2/3，成功地优化了系统的线性度。 |
| 关键词: 配电网 光载无线系统 非线性失真 马赫-曾德尔调制器 无杂散动态范围 |
| DOI：10.7667/PSPC161386 |
| 投稿时间：2016-08-25修订日期：2016-11-06 |
| 基金项目:国家自然科学基金资助项目(61405142) |
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| Research on the linearity of radio-over-fiber system for distribution network communication |
| SUN Jiake,DU Ke |
(School of Engineering & Applied Science, Washington University in St.Louis, St.Louis, MO 63105, USA
;Ponovo Power Co., Ltd., Beijing 100176, China) |
| Abstract: |
| The nonlinearity in conversion between electric signal and light signal will make terrible effect on the performance of radio-over-fiber (RoF) system. As a result, how to decrease the nonlinearity and improve the performance of the link becomes the focal point. Based on the former researches, this paper aims at studying the method to inhibit the third order inter-modulation distortion (IMD3), caused by the nonlinearity of the modulator, and then to get higher linearity of the system. Firstly, the basic plan to achieve RoF system is proposed. The linearity of the system is not good resulting from the serious nonlinear distortion of the modulator, and the result shows that Spurious free dynamic range (SFDR) of this plan can only reach 111.32 dB.Hz2/3. Based on the first plan, an improved scheme is proposed. In order to improve the linearity, this scheme adds a Mach–Zehnder Modulator (MZM) and a phase shifter to generate an unmodulated optical carrier, so the main carrier from the unmodulated signal and the main carrier caused by the modulated signal can inhibit each other. Under this plan, SFDR can reach 121.8 dB.Hz2/3. The experimental results show that SFDR of the second scheme is 10.48 dB.Hz2/3 higher than that of the basic one and the linearity of the system has been improved successfully. This work is supported by National Natural Science Foundation of China (No. 61405142). |
| Key words: distribution network radio over fiber system nonlinear distortion Mach-Zehnder modulator spurious free dynamic range |
