中文摘要：

OFDM技术与ROF技术结合为实现低成本、高速数据传输的移动网络提供了可能,但光纤链路的非线性以及无线信道的多径衰落降低了系统性能。在建立ROF下行链路的传输函数模型基础上,分析ROF下行链路对OFDM信号性能的影响。传输模型包括激光器,光纤链路以及无线信道。分析在不同光调制指数、光纤长度及无线多径信道下接收信号的误差矢量、三阶非线性失真和互调失真。仿真结果显示：随着调制指数、光纤长度的增加,以及无线信道的多径衰落使得接收信号性能下降。此分析为OFDM-ROF下行链路的线性化以及无线信道均衡方案选择提供了理论基础。

英文摘要：

The integration of Orthogonal Frequency Division Multiplexing（OFDM） with Radio over Fiber（RoF） technique provides the possibility of cost-effective and high data-rate wireless networks.However,the nonlinear effects and multipath fading of wireless channel could severely degrade the performance of RoF as well as OFDM system.In this paper,based on the transfer function model of the ROF downlink,the performance of OFDM based ROF link is analyzed.And this transfer model includes the laser diode,single mode fiber and wireless channel.The error vector,third-order nonlinear distortion and intermodulation distortion of the received signal under different modulator index,fiber length and multipath wireless channel are discussed.Simulation results show that the performance of received OFDM signals would decrease with the increase of modulator index and fiber length as well as the multipath fading of wireless channel.These discussions and analyses provide a theoretical basis for linear and equalization algorithm of OFDM-ROF downlink.