Adaptive Full-Duplex Jamming Receiver for Secure D2D Links in Random Networks

TL;DR

This paper introduces an adaptive full-duplex/half-duplex switching receiver for secure device-to-device communication, optimizing secrecy throughput under resource constraints and residual interference, outperforming fixed-mode approaches.

Contribution

It proposes a novel adaptive switching scheme for D2D links that optimizes secrecy performance considering residual self-interference, with low online complexity and practical implementation insights.

Findings

Adaptive switching improves secrecy throughput over fixed modes.

Secrecy throughput is a quasi-concave function of system parameters.

The scheme achieves higher secrecy rates with limited online computation.

Abstract

Device-to-device (D2D) communication raises new transmission secrecy protection challenges, since conventional physical layer security approaches, such as multiple antennas and cooperation techniques, are invalid due to its resource/size constraints. The full-duplex (FD) jamming receiver, which radiates jamming signals to confuse eavesdroppers when receiving the desired signal simultaneously, is a promising candidate. Unlike existing endeavors that assume the FD jamming receiver always improves the secrecy performance compared with the half-duplex (HD) receiver, we show that this assumption highly depends on the instantaneous residual self-interference cancellation level and may be invalid. We propose an adaptive jamming receiver operating in a switched FD/HD mode for a D2D link in random networks. Subject to the secrecy outage probability constraint, we optimize the transceiver parameters, such as signal/jamming powers, secrecy rates and mode switch criteria, to maximize the secrecy throughput. Most of the optimization operations are taken off-line and only very limited on-line calculations are required to make the scheme with low complexity. Furthermore, some interesting insights are provided, such as the secrecy throughput is a quasi-concave function. Numerical results are demonstrated to verify our theoretical findings, and to show its superiority compared with the receiver operating in the FD or HD mode only.