Analysis of improved performance for a satellite-to-ground coherent optical communication system with DQPSK modulation due to phase estimation

The performance of a satellite-to-ground optical communication system with phase modulation is limited by phase fluctuations induced by atmospheric turbulence. To improve the system performance, one effective way is to use coherent detection. In this paper, a satellite-to-ground coherent optical communication system with differential quadrature phase-shift keying (DQPSK) modulation is studied, and a phase estimation algorithm based on M-th power scheme is used. The simulation results show that the phase noise induced by atmospheric turbulence can be suppressed greatly.