基于RIS-UAV协作的车载通信系统安全传输研究

Secure Transmission Scheme for V ehicular Communication with RIS-UAV Relay Cooperation

针对城市复杂的交通环境导致车载通网络信息传输安全性低、数据速率缓慢以及地面中继受限等问题,提出一种可重构智能表面(RIS)辅助无人机(UAV)中继协作的车载通信系统安全传输方案。该方案首先根据系统平均传输速率最大化来设计无人机轨迹优化问题。接着,通过引入松弛变量的序列凸规划交替迭代算法解决无人机轨迹的非凸问题,得到平均速率最大化的UAV飞行轨迹。最后,通过适当调整RIS与窃听用户之间的位置来降低窃听信道容量,改善无线传输环境。数值分析表明,优化无人机轨迹,可以得到最优平均传输速率。在RIS技术辅助下通过合理设置参数,该传输方案能有效提高通信系统的传输速率,同时也能保证安全性能。

The complex urban traffic environment leads to problems of low information transmission security,slow data rate,and limited ground relay in vehicular communication network.A secure transmission scheme for vehicular communication scheme is proposed with RIS-assisted(reconfigurable intelligent surface-assisted)unmanned aerial vehicle(UAV)relay cooperation.In this scheme,the UAV trajectory optimization problem is designed according to the maximum average transmission rate of the system.And then,the non-convex problem of the UAV trajectory is solved by introducing a sequential convex programming alternating iterative algorithm of relaxed variables,which yields the UAV flight trajectory of the maximizing average transmission rate.Finally,the capacity of the eavesdropping channel can be reduced by properly adjusting the position between the RIS and the eavesdropping user,and the wireless transmission environment can be improved.Numerical analysis shows that the maximum average transmission rate can be obtained by optimizing the trajectory of the UAV.With the assistance of RIS,the proposed secure transmission scheme can effectively improve the transmission rate of the communication system and ensure the safety performance though reasonable parameter settings.