Performance analysis of degree of polarization using PMD compensation in DP-DQPSK

A novel dual polarization differential quadrature phase shift keying (DP-DQPSK) system is proposed, whose receiver is the same as the single polarization DQPSK system, while it does not need polarization de-multiplexing like the conventional polarization division multiplexing QPSK (PDM-QPSK). Polarization mode dispersion (PMD) is mainly considered and PMD compensation for the DP-DQPSK system is studied. As the feedback signal for PMDcompensation, the degree of polarization of the signals is discussed in detail. The results show that PMD tolerance can be improved by 89 ps within 1 dB optical signal noise ratio penalty after PMD compensation for the DP-DQPSK system.