Legitimate eavesdropping of wireless powered suspicious communication networks with a monitoring power station

Abstract

This paper investigates the legitimate eavesdropping of a wireless powered suspicious communication network. The considered network consists of a wireless powered suspicious transmitter, a suspicious receiver, and a power station. The power station is assumed to be also a monitor to legitimately eavesdrop the suspicious communication with the help from a wireless powered jammer. The problem for maximizing the average eavesdropping rate under the minimum suspicious communication rate constraint and the transmit power constraint at the monitor is investigated, where the time allocation for energy transferring and information transmission, and the power controls of the monitoring power station and the jammer are jointly optimized. By using the Lagrange duality method and exploring the particular problem structure, the closed-form optimal solution is derived. Some valuable insights are also obtained from the optimal solution. Extensive simulations are provided to confirm the superiority of the proposed optimal solution compared to various benchmark algorithms.