2 research outputs found
Improving Anti-Eavesdropping Ability without Eavesdropper's CSI: A Practical Secure Transmission Design Perspective
This letter studies the practical design of secure transmissions without
knowing eavesdropper's channel state information (ECSI). An ECSI-irrelevant
metric is introduced to quantize the intrinsic anti-eavesdropping ability (AEA)
that the transmitter has on confronting the eavesdropper via secrecy encoding
together with artificial-noise-aided signaling. Non-adaptive and adaptive
transmission schemes are proposed to maximize the AEA with the optimal encoding
rates and power allocation presented in closed-form expressions. Analyses and
numerical results show that maximizing the AEA is equivalent to minimizing the
secrecy outage probability (SOP) for the worst case by ignoring eavesdropper's
receiver noise. Therefore, the AEA is a useful alternative to the SOP for
assessing and designing secure transmissions when the ECSI cannot be prior
known.Comment: 4 pages, 2 figures, to be published on IEEE Wireless Communications
Letters (WCL
Multi-antenna Wireless Legitimate Surveillance Systems: Design and Performance Analysis
To improve national security, government agencies have long been committed to
enforcing powerful surveillance measures on suspicious individuals or
communications. In this paper, we consider a wireless legitimate surveillance
system, where a full-duplex multi-antenna legitimate monitor aims to eavesdrop
on a dubious communication link between a suspicious pair via proactive
jamming. Assuming that the legitimate monitor can successfully overhear the
suspicious information only when its achievable data rate is no smaller than
that of the suspicious receiver, the key objective is to maximize the
eavesdropping non-outage probability by joint design of the jamming power,
receive and transmit beamformers at the legitimate monitor. Depending on the
number of receive/transmit antennas implemented, i.e., single-input
single-output, single-input multiple-output, multiple-input single-output and
multiple-input multiple-output (MIMO), four different scenarios are
investigated. For each scenario, the optimal jamming power is derived in
closed-form and efficient algorithms are obtained for the optimal
transmit/receive beamforming vectors. Moreover, low-complexity suboptimal
beamforming schemes are proposed for the MIMO case. Our analytical findings
demonstrate that by exploiting multiple antennas at the legitimate monitor, the
eavesdropping non-outage probability can be significantly improved compared to
the single antenna case. In addition, the proposed suboptimal transmit
zero-forcing scheme yields similar performance as the optimal scheme