Abstract:Satellite laser communication link is a key technology for achieving large-scale constellation networking of satellites. Coherent laser link has high sensitivity, resistance to background interference, and large space for rate upgrade, making it widely using in inter-satellite laser link. In this paper, a signal-to-noise-ratio(SNR) analysis model is established for satellite coherent laser communication terminal with front EDFA. The effects of EDFA power gain, EDFA noise figure, local optical power, signal optical power, optical bandwidth, and electrical bandwidth on the terminal output SNR and the power ratio of various output noise are analyzed by simulation. The SNR characteristics of satellite coherent laser communication terminal with front EDFA are obtained. The results of this paper can guide the design of satellite coherent laser communication terminal.