Abstract: Due to polarization mode dispersion(PMD) and polarization dependent loss(PDL) in a system, the coherent detection scheme was chosen at the receiver side of the system and T-CMN algorithm was used to separate the polarization multiplexed signals. Simulation results show that after demultiplexed by independent component analysis(ICA), the transmission quality of polarization signals is obviously improved, and when the optical signal to noise ratio of the system is greater than 20.86 dB, the bit error rate can be kept lower than10?9, which meets the requirement of a communication system.