基于阵列接收机的大气激光通信系统性能研究

Performance study of laser communication system adopting multiple receivers through atmospheric turbulence

在Rytov的激光大气湍流传输理论基础上,考虑到大气湍流引起的强度起伏、孔径平均效应和阵列接收机数量对激光通信系统性能的影响,建立了描述基于阵列接收机系统的孔径平均因子、有效信噪比和误码率的数学模型,数值模拟了湍流强弱、孔径尺寸和接收机数量对系统通信质量的影响。结果表明:中强湍流区对误码率和孔径平均因子的影响明显大于弱湍流区,大尺寸接收孔径可以有效减小强度起伏。当湍流强度一定时,增加接收机的数量可以大幅提高系统的信噪比和有效通信距离,对工程上提高激光通信的质量具有一定的指导意义。

Based on Rytov＇ s theory＂ model of laser propagation in the atmospheric turbulence, considering the effects of intensity fluctuations, aperture averaging effect and values of receiver that induced by the atmospheric turbulence on the performance of free space optical（FSO） communication system, a coupled mathematical model is built to depict the aperture averaging factor, effective signal-to-noise ratio （SNR） and bit error rate （ BER ） of an FSO system with muhiple receivers. The influence of turbulent intensity, the size of receiver aperture and values of receiver on tile perfomlance of communication system is also simulated. The results show that in medium and strong turbulence field, the influence of BER and aperture averaging factor is very obvious than that in weak turbulence field, and the larger diameter can ef- fectively reduce the intensity fluctuations. In addition, under a certain intensity of turbulence the larger numbers of re- ceivers is,the better the effective SNR and BER of FSO system is,which is guide significance for improving the quality of laser communication system.