中文摘要：

建立了一个OFDM-ROF实验仿真系统,对该系统下行链路性能进行了仿真计算,并采用了远程光外差技术来产生毫米波信号。用一个低频的信号源对激光进行载波抑制的双边带调制来产生频率差为毫米波频率的两束相干激光源。用Matlab软件编写了OFDM的调制和解调模块,用OptiSystem软件搭建了该系统光纤传输部分的实验仿真平台,给出了系统仿真框图和仿真计算结果。最后,针对解调后星座图随传输距离产生旋转的现象,分析了光纤色散对系统性能的影响,并用信道估计的方法对色散进行了补偿,并给出了色散补偿前后系统误码率与传输距离的关系曲线。仿真结果表明,在色散补偿后该OFDM-ROF系统有效传输距离得到了极大的提高。

英文摘要：

A simulation system of OFDM-ROF was established.By using the optical remote heterodyne detection technique,downlink performance of the system was simulated.Two coherent laser beams were produced by carrier suppressed double sideband modulation with a low frequency signal source.The frequence difference between laser beams was the millimeter wave frequency.The module of modulation and demodulation of OFDM was established by using Matlab software and OptiSystem software for the part of fiber link in the system.System simulation block diagram and simulation results were given.Finally,for the phenomenon of the rotation of the constellation,the influence of fiber dispersion on system performance was analyzed and the dispersion was compensated by the way of channel estimation.The relation between the BER and the transmission distance with dispersion compensated and before were given.Simulation results show that the OFDM-ROF system has a great increase of the effective transmission distance.