Analysis of Communications and Network Stability in RIS-Assisted UAV-USV Collaborative System

Recently, unmanned aerial vehicles (UAVs) and reconfigurable intelligent surfaces (RIS) have been widely utilized in wireless communications to enhance data transmission link quality by proactively reconfiguring the radio wave propagation environments. Aiming to realize wireless communication and network stability in inland waterway communications, the collaborative operations of RIS-carried UAV and unmanned surface vehicles (USVs) have captured considerable attention within both academic and industrial circles. In this paper, a novel RIS-assisted UAV-USV collaborative network architecture considering network stability is proposed, where RIS-assisted data transmission and control law of USVs are demonstrated. Aiming to investigate the relationship between USVs data transmission and network stability, the analysis of network stability considering USVs data transmission latency is taken into consideration. In particular, a Lyapunov function is proposed. Moreover, the corresponding expression of transmission latency and SNR threshold of each wireless link between any two USVs can be obtained when the network reaches asymptotically stable. The preliminary results verify the effectiveness of theoretical analysis, where the performance of USVs space error, velocity error, and channel SNR are demonstrated.