Point error effect on MDPSK space optical communication system

Bit error rate (BER) performance is an important indicator to measure the quality of a space optical communication system. Phase modulation technology is an increasingly popular modulation format used in such a system as it provides a better BER performance. M-ary differential phase shift keying (MDPSK) is a new format of phase modulation technologies. In this paper, we discuss a situation that point error is the only mechanical system effect on a MDPSK free space optical communication system. We give the BER expression of a MDPSK system under the effect of point error. Then we numerically analyze several link parameters such as transmission power, transmission aperture, divergence angle and receiver diameter. We concentrate on analyzing how each parameter influences the BER performance of the MDPSK system. These research works are of great value for the study of communication quality in a free space optical communication system with MDPSK modulation format.