Analysis of transmitter-blocking technique for terrestrial FSO links

The paper deals with an analytical model of the transmitter-blocking technique for mitigating short-time fades on free-space optical links. Due to the effect of atmospheric turbulence, the optical channel is characterized by received power fades in the order of tens of milliseconds, during which the transmitted data is lost. Under certain conditions, the propagation through turbulent channel is reciprocal, i.e. the power fluctuations at the near and far ends are highly correlated, which allows the channel state estimation at the receiver. During a fade, the incoming data is stored in a buffer and transmitted when the link becomes operational again. Based on lognormal process approximation, the paper provides a fully parametrized analytic model for the estimation of fade frequency and duration, which can be used to estimate the buffer capacity and optimum control strategy.