一种高线性度的全双工光载射频系统

A High Linearity Full-duplex Radio over Fiber System

本文提出了一种高线性度的全双工光载射频系统.该系统克服了下行链路三阶交调失真与周期性功率衰落的影响,同时对上行链路进行波长重用,简化了基站的成本和复杂度,实现了高线性度的全双工光载射频系统.实验结果表明,与基于单个马增调制器的常规系统相比,本系统下行链路中三阶交调失真得到明显抑制,克服了光纤色散引起的功率衰落,系统无杂散动态范围提高17dB,宽带信号的星座图和误差矢量幅度改善明显,另外,上行链路可以实现稳定的波长重用及宽带信号传输.

In this paper,a full-duplex radio over fiber system with high linearity is proposed.The system overcomes the influence of the third-order intermodulation distortion and the periodic power fading in the downlink.At the same time,wavelength reuse is used in the uplink,which simplifies the complexity of the base station.A full duplex radio over fiber system with high linearity is realized.The experimental results show that compared with the conventional system based on single Mach Zehnder modulator,the third-order intermodulation distortion in the downlink of the proposed system is obviously suppressed and the influence of fiber dispersion is overcome,the spurious free dynamic range of the system is improved by 17dB,and the constellation and error vector amplitude of broadband RF signal are improved significantly.In addition,the uplink can achieve stable wavelength reuse and modulation transmission.