Coding-Enhanced Cooperative Jamming for Secret Communication in Fluid Antenna Systems

TL;DR

This paper proposes a novel coding-enhanced cooperative jamming scheme for fluid antenna systems to improve secrecy rates by allowing the legitimate receiver to cancel interference while preventing eavesdroppers from decoding the jamming signal.

Contribution

It introduces a new coding-based jamming approach tailored for fluid antenna systems, optimizing secrecy rate through port selection and power control.

Findings

Secrecy rate is significantly increased with the proposed scheme.

Optimal port selection and power control improve security performance.

Simulation confirms effectiveness of fluid antenna and coding-enhanced jamming.

Abstract

This letter investigates the secret communication problem for a fluid antenna system (FAS)-assisted wiretap channel, where the legitimate transmitter transmits an information-bearing signal to the legitimate receiver, and at the same time, transmits a jamming signal to interfere with the eavesdropper (Eve). Unlike the conventional jamming scheme, which usually transmits Gaussian noise that interferes not only with Eve but also with the legitimate receiver, in this letter, we consider that encoded codewords are transmitted to jam Eve. Then, by employing appropriate coding schemes, the legitimate receiver can successfully decode the jamming signal and then cancel the interference, while Eve cannot, even if it knows the codebooks. We aim to maximize the secrecy rate through port selection and power control. Although the problem is non-convex, we show that the optimal solution can be found. Simulation results show that by using the FAS technique and the proposed jamming scheme, the secrecy rate of the system can be significantly increased.