Efficient crosstalk mitigation of OAM based 400-Gbit/s QPSK data transmission in 1.1-km vortex fiber by using soft-decision LDPC codes

The efficient mitigation of crosstalk-induced “error floor” in system performance by using soft-decoding LDPC codes in an OAM-based four modes multiplexed fiber transmission system is experimentally demonstrated. A significant coding gain of >15.5 dB is achieved, depending on the amount of crosstalk from other channels.