基于虚拟子载波降低光正交频分复用信号峰均功率比新方法的实验研究

Experiment for Optical Orthogonal Frequency Division Multiplexing System Peak to Average Power Ratio Reduction with a New Scheme Using Dummy Subcarriers

光正交频分复用(O-OFDM)是一种有效降低符号间干扰的高速数据调制技术。在技术实现过程中若峰值平均功率比(PAPR)过高,发射机和接收机内部放大器线性要求就会很高,从而限制了O-OFDM调制技术的实际应用。总结了目前国内外降低PAPR的多种技术,在此基础上,给出了PAPR的定义和分布,并提出了一种新的基于虚拟子载波来降低光OFDM系统PAPR的方法,该方法在发送端不需要传输OFDM信号的边带信息,接收端不需增加额外处理。实验和仿真结果证明,经200km标准单模光纤(SSMF)传输后,该方法既能更加有效地抑制O-OFDM的PAPR,又能改善系统的误码率(BER)性能和降低传统虚拟子载波技术计算的复杂度。

Optical orthogonal frequency division multiplexing （O-OFDM） is an efficient modulation technology for reduction of intersymbol interference. There is a strict requirement for the linear characteristics of amplifiers in transmitters and receivers if the peak to average power ratio （PAPR） is high in the implementation of O-OFDM modulation technology, which limits the practical employment of O-OFDM. Various techniques on reducing the PAPR are summarized, and the definition and distribution of PAPR are introduced. In order to contain the PAPR in O-OFDM systems, a new scheme for optical OFDM system PAPR reduction using dummy subcarrier is presented, which does not need to send sideband information in the transmitter and does not need additional treatment in the receiver. The experimental results show that the method can not only reduce the PAPR and the complexity of the calculation, but also improve the bit error rate （BER） of the system when the O-OFDM signals transmits over 200 km standard single-mode fiber （SSMF）.