Jamming-Assisted Wireless Information Surveillance With Movable Antenna

Movable antenna (MA) is an emerging technology that can significantly enhance the communication capacity by flexibly adjusting the antenna positions to reconstruct wireless channels. In this letter, MA technology is applied for the first time in the field of wireless surveillance, consisting of a suspicious transmitter (ST), a suspicious receiver (SR), a legitimate monitor (E) and a MA-enabled jammer (J). Specifically, J aims to proactively interfere with the SR to reduce the suspicious transmission rate of the ST, so as to facilitate effective eavesdropping by E. Our goal is to maximize the eavesdropping success probability at E by jointly optimizing antenna positions and the jamming beamforming at J. However, the problem is highly non-convex because the mutual coupling between above two variables. To tackle this challenge, we design two schemes to obtain the locally optimal and suboptimal antenna positions. Furthermore, we successfully derive a closed-form result for the critical antenna span. The simulation results show that, compared to the traditional fixed position antenna (FPA), our proposed schemes achieve a significant performance improvement, while the derived critical antenna span approaches the result originated from Monte Carlos.