Physical Layer Security for IoT Application With Assistance of Active STAR-RIS

The application of internet of things (IoT) may suffer from serious security issue, such as the attack and wiretap from jammers and eavesdroppers, which results in the degradation of reception of useful signals at the IoT devices (users), affecting the secrecy performance for the IoT application. In this work, we propose to introduce an active simultaneously transmitting and reflecting reconfigurable intelligent surface (ASTAR-RIS) to resist jamming and eavesdropping caused by multiple jammers and eavesdroppers, respectively. For the security purpose, we formulate a sum rate maximization problem subject to the imperfect channel state information and maximum tolerable leakage rate at the eavesdroppers. By jointly optimizing beamformers at the base station and that at the ASTAR-RIS including phase shifts and amplification factors, simulation results show that the proposed robust scheme is able to provide significant improvement as compared with other baselines.