Wireless Surveillance with Interference Exploitation in Unauthorized Underlaid D2D Networks

Interference exploitation has been considered an effective method to improve secrecy in underlaid device-to-device (D2D) communication networks. This paper studied interference exploitation in unauthorized underlaid D2D communication networks, where a cellular user (CU) transmits uplink information to a base station (BS) and a pair of suspicious D2D users (DUs) transmit the suspicious information at the same time. We used the beamforming of the full-duplex (FD) CU to simultaneously achieve the legitimate uplink transmission of the CU and wireless surveillance on the suspicious DUs. Considering the different priority levels of the tasks, we divided the real-time quality of service (QoS) requirements of the CU into three cases and formulated the problem in each case. We derived beamforming expressions for each problem in the perfect self-interference cancellation (PSIC) and then proposed targeted algorithms in the imperfect self-interference cancellation (ISIC). Finally, simulation results are provided to validate the effectiveness and the advantages of our proposed schemes in situations with different QoS requirements.