中文摘要：

提出了一种适用于强度调制直接检测（IM/DD）光系统的信号调制格式。这种基于Nyquist脉冲half cycle副载波调制（SCM）信号能有效提高频谱效率,为了减少传递函数引起的系统的性能恶化,采用了数字预均衡和后均衡实现对光纤损伤的补偿;建立了偏振复用（PDM）IM/DD系统平台,分析了Nyquist脉冲SCM信号在系统中的PAPR性能,实现了72Gbit/s 64-QAM Nyquist脉冲SCM信号经过20km标准单模光纤（SMF）传输后其误码性能小于前向纠错（FEC）阀值3.8×10-3。

英文摘要：

A signal modulation format which is suitable for intensity modulation direct detection （IM/DD） optical system is proposed. The signal based on Nyquist pulse subcarrier modulation （SCM） can effec- tively improve the spectrum efficiency. In order to reduce the performance deterioration caused by the system transfer function, digital pre- and post-equalization are applied in the system. We establish the ex-periment setup of polarization division multiplexing （PMD） intensity modulation direct detection optical system with pre-equalization and analyze the peak to average power ratio （PAPR） of Nyquist pulse sub- carrier modulation signal. The experiment successfully achieves the bit error rate （BER） of 64QAM Nyquist pulse subcarrier modulation signal less than forward-error-correction （FEC） threshold after transmission along 20 km standard single-mode fiber （SSMF）for the first time.