中文摘要：

研究基于单边带调制（SSB）的直接探测光正交频分复用-光载射频（OFDM-RoF）系统的性能。10Gbit/s的二进制数据信号经过QAM符号映射和OFDM调制后,与10GHz射频信号混频并驱动双电极LiNbO3马赫-曾德尔调制器（LN-MZM）产生SSB-OFDM信号,调制信号通过光纤传输至基站,进行直接探测转换为毫米波电信号后再无线发送到用户端。仿真结果证实,OFDMRoF系统在4QAM和16QAM两种调制格式下的EVM都满足FEC的要求。同时,理论分析并仿真验证存在一个最佳调制指数可以使信号传输性能达到最佳,并且最佳调制指数与光纤长度无关。

英文摘要：

An orthogonal frequency-division multiplexing radio-over-fiber （OFDM-RoF） system based on single sideband （SSB） modulation and direct detection is proposed and simulated. The 10-Ghit/s binary data signal is mapped by quadrature amplitude modulation （QAM） and modulated as the baseband OFDM signal which is mixed with the 10 GHz radio frequency （RF） clock. The RF OFDM signal then drives the dual-electrode LiNbO3 Mach-Zehnder modulator （LN-MZM） to generate the optical SSB- OFDM signal Which is transmitted to base station （BS） over standard single-mode fiber （SMF） and broadcast by antenna to user terminals. The simulation results demonstrate that the error vector magnitudes （EVMs） of the 4QAM- and 16QAM-OFDM signals are much below the forward error correction （FEC） limits. Meanwhile,the theoretical analysis and simulation are preformed to verify that an optimum modulation index exists, which can bring on optimum transmission performance regardless of the fiber length.