Eavesdropping mitigation for wireless communications over single-input–single-output channels

In this study, the authors investigate eavesdropping mitigation for wireless communications with physical-layer security techniques. They consider a multicasting scenario with one transmitter, multiple trusted receivers and multiple eavesdroppers, each equipped with one antenna. Aiming at protecting trusted communications from data interception, they develop two novel waveform designs for eavesdropping reduction under two scenarios: (i) when the eavesdroppers´ channel state information (CSI) is known, they design the waveform and transmit energy which can minimise the maximal signal-to-interference-plus-noise ratios (SINRs) at the eavesdroppers while achieving guaranteed SINRs at the trusted receivers and (ii) when the eavesdroppers´ CSIs are not available, they adopt `artificial noise´ (AN) strategy aiming at generating as much disturbance to eavesdroppers as possible. A novel waveform and transmit power design is proposed which can maximise the AN´s energy with assured quality-of-service at trusted receivers. Extensive simulation studies illustrate the efficiency of the proposed designs for eavesdropping mitigation in wireless communications.