  We study a high throughput satellite system, where the feeder link uses
free-space optical (FSO) and the user link uses radio frequency (RF)
communication. In particular, we first propose a transmit diversity using
Alamouti space time block coding to mitigate the atmospheric turbulence in the
feeder link. Then, based on the concept of average virtual
signal-to-interference-plus-noise ratio and one-bit feedback, we propose a
beamforming algorithm for the user link to maximize the ergodic capacity (EC).
Moreover, by assuming that the FSO links follow the Malaga distribution whereas
RF links undergo the shadowed-Rician fading, we derive a closed-form EC
expression of the considered system. Finally, numerical simulations validate
the accuracy of our theoretical analysis, and show that the proposed schemes
can achieve higher capacity compared with the reference schemes.
