Physical Layer Security Analysis in the Priority-Based 5G Spectrum Sharing Systems

In this work, we study an eavesdropping attack in a priority-based 5G spectrum sharing system and analyze the secrecy performance of the sharing systems through the secrecy outage probability analysis. We consider two spectrum sharing scenarios for the analysis of such a priority-based sharing. In the first scenario, the higher priority system fairly shares the spectrum with a lower priority system, and we show the impact of jointly securing the transmissions can be balanced between the higher priority and the lower priority system. In the second scenario, the higher priority system requires to decode the messages of the lower priority system. In this case, we observe that the lower priority transmissions could help the higher priority system achieve a better secrecy performance. For each scenario, we present a secrecy outage probability analysis which can be used as an indicator of the level of secrecy for each sharing system.