A security enhancement analysis of full duplex cooperative rate-splitting

Message security is crucial for full-duplex (FD) cooperative rate splitting (CRS) system. Since the remote user’s common message can be decoded by the relay user, and the near user needs to be transmitted as a relay, it is necessary to prevent the remote user’s private message from being eavesdropped by the near user. In addition, the remote user must also prevent the potential external eavesdropper from eavesdropping on his message. Therefore, this paper considers the security performance of remote user in FD-CRS networks facing both external eavesdropping and internal eavesdropping. We aim to maximize the remote user security rate under the constraints of transmission power and common rate allocation. Due to the non-convexity of the problem, we propose an iterative algorithm based on successive convex approximation (SCA) to solve it. Our simulation results show that the FD-CRS significantly outperforms half-duplex (HD)-CRS and non-cooperative schemes in terms of security.