Optimum ratio of beam divergence angle to pointing error for satellite-ground laser link

The transmitter beam is Gaussian for real satellite-ground laser communication system. The pointing jitter and atmospheric scintillation are the main noise sources for satellite-ground laser link. The channel model of satellite-ground laser communication link is presented in presence of the effects of atmospheric scintillation and pointing jitter on the quality of communication. The problem of the optimum ratio of beam divergence angle to pointing error is analyzed. The results indicate that there is an optimum ratio of beam divergence angle to pointing error that maximizes the link margin for different requirement of bit error rate for uplink, and there is an optimum ratio of beam divergence angle to pointing error that minimizes the required transmitter power to satisfy the bit error rat