中文摘要：

对模分复用（MDM）系统中传输容量和模式串扰问题进行了研究，在VPItransmissionMaker仿真平台设计并构建了一种新型6×6多输入多输出（MIMO）MDM系统。本文系统使用高模式差分群时延（MDGD）光子晶体少模光纤（PC-FMF），实现包括（LP_01、LP_11a、LP_11b、LP_21a、LP_21b、LP_02）在内六模式相对独立的传输，结合恒模算法（CMA）对输出信号解复用。仿真实验结果表明，在系统的光信噪比（OSNR）为22dB时，每个模式携带传输速率为40 Gbit／s的4QAM调制信号，实现了在PC-FMF中稳定传输34km，保证了每个模式信号的误码率（BER）均在10-5量级以下，满足通信系统传输最低要求。与传统FMF的MDM系统相比，本文设计的基于PC-FMF的MDM系统可有效消除模式间串扰，提高MDM系统的容量，在高速大容量光传输系统中具有重要价值。

英文摘要：

Aim at the transmission capacity and the mode crosstalk of mode division multiplexing （MDM） system,we design and set up a new-type 6 × 6 multiple input multiple output （MIMO） MDM system with the VPItransmissionMaker simulation platform. This system uses a photonic crystal few-mode fiber （FMF） which has high mode differential group delay （MIX）D）,and the transmissions of all modes in- cluding LP_01, LP_11a, LP_11b, LP_21a, LP_21b, LP_02 are relatively independent, combined with constant modu- lus algorithm （CMA） to achieve the output signal for de-multiplexing. The simulation results show that when the signal to noise ratio （SNR） of this system is 22 dB, each mode carries a transfer rate of 40 Gbit/s signal by 4QAM modulation, transmit 34 km in the photonic crystal FMF, and it ensures the bit error rate （BER） of each mode is under 10-5 orders of magnitude,which meets the minimum require- ment of communication system transmission. Compared with MDM systems using traditional FMF,this system can effectively eliminate crosstalk between all modes, and it can significantly improve the capacity of MDM system, so it will have significant applications in the high-speed and large-capacity optical trans- mission system.