基于级联ISFA信道估计的光OFDM系统研究

Investigation of optical OFDM systems based on cascade ISFA channel estimation

采用训练序列与级联符号内频域平均(intra-symbol frequency-domain averaging,ISFA)的信道估计方法提高了直接检测光正交频分复用(OFDM)接收机中信道估计的准确性。通过Matlab编程建立了强度调制直接检测系统仿真平台,对不同调制格式的OFDM信号进行了数值仿真分析。结果表明,级联ISFA方法可以提供更为准确的信道估计,有效改善高阶QAM调制的OFDM信号误码性能,提高接收机的灵敏度。

A training sequence（TS） and cascade intra-symbol frequency-domain averaging （ISFA） method is proposed to improve the accuracy of channel estimation in intensity modulated and directly-detection optical orthogonal frequency-division multiplexing （IMDD-OOFDM） systems. The simulation platform of IMDD is established by employing mathworks Matlab software, and then the numerical simulation analysis of the sys- tem with different modulation formats and cascaded ISFA is also performed. The results show that the cascad- ed ISFA method can provide more accurate channel estimation, and effectively improve the bit error ratio per- formance of high-order QAM modulated OFDM signal and receiver sensitivity.