Performance Analysis of Satellite-Vehicle Networks With a Non-Terrestrial Vehicle.

In this work, we propose a non-terrestrial vehicle communication network where the communication between the satellite and the terrestrial source is assisted by a unmanned aerial vehicle (UAV) used as a relay. In particular, a reconfigurable intelligent surface (RIS) is used in the RF channel to reflect the signals of the terrestrial user to the relay with a fixed amplification gain, while free-space optical (FSO) is applied to the relay-satellite link to obtain a high speed transmission. For such a dual-hop system, assuming that the FSO channel experiences $\mathcal {M}$ -distributed fading with pointing errors, the expressions for the outage probability (OP) and average bit error rate (ABER) are evaluated in closed-forms. In addition, the high signal-to-noise ratio (SNR) analyses for the OP and ABER are developed and the lower and upper bounds on the average channel capacity (ACC) are calculated to obtain further insights. Results show that the diversity order of the proposed system is $\min \lbrace k_{w},m_{w}\rbrace$ , where these two parameters are related to the Nakagami- m distribution parameters and the number of RIS elements. Finally, we take the shadowing effects into consideration, and it can be seen that the shadowing effects significantly degrade the system performance.