Proactive Eavesdropping via Jamming Over Multiple Suspicious Links With Wireless-Powered Monitor

This letter studies jamming-assisted proactive eavesdropping over multiple orthogonal suspicious links with a wireless-powered monitor. Considering the shortage of energy, the monitor adopts the power splitting technique to divide each of the received suspicious signals into two parts for information decoding and energy harvesting, and then exploits the accumulated energy to jam over those suspicious links, to reduce the corresponding suspicious communication rate and facilitate the eavesdropping of the monitor itself. Our objective is to maximize the minimum eavesdropping success probability of the monitor for all received suspicious signals, by jointly optimizing its power splitting ratios and jamming power allocations. The formulated problem involves the complex Lambert function and is highly non-convex. To tackle this challenge, first we derive a very tight approximation of the Lambert function based on its key property. Then, we employ the general successive convex approximation (SCA)-based technique to iteratively find a locally optimal solution. Moreover, we propose a parallel coordinate descent (PCD)-based low-complexity algorithm to obtain a sub-optimal solution. Numerical results show the effectiveness of our proposed schemes compared to competitive benchmarks.

Automated summary

This letter studies jamming-assisted proactive eavesdropping over multiple orthogonal suspicious links with a wireless-powered monitor. The objective is to maximize the minimum eavesdropping success probability of the monitor for all received suspicious signals. A tight approximation of the Lambert function and successive convex approximation (SCA)-based technique are proposed to solve the complex problem. A parallel coordinate descent (PCD)-based low-complexity algorithm is also introduced to obtain a sub-optimal solution.