Index Modulation Based Coordinate Interleaved Orthogonal Design for Secure Communications

TL;DR

This paper introduces a novel index modulation scheme based on coordinate interleaved orthogonal designs (CIOD) that enhances spectral efficiency and security in wireless communications by using artificial noise and analyzing practical channel estimation issues.

Contribution

It proposes the CIOD-IM scheme, combining index modulation with CIOD for improved security and spectral efficiency, along with analytical expressions and simulation validation.

Findings

Outperforms existing IM-based schemes in secrecy rate and BER.

Provides analytical expressions for ergodic secrecy rate and BER bounds.

Shows robustness under imperfect channel estimation.

Abstract

In this paper, we propose a physical layer security scheme that exploits a novel index modulation (IM) technique for coordinate interleaved orthogonal designs (CIOD). Utilizing the diversity gain of CIOD transmission, the proposed scheme, named CIOD-IM, provides an improved spectral efficiency by means of IM. In order to provide a satisfactory secrecy rate, we design a particular artificial noise matrix, which does not affect the performance of the legitimate receiver, while deteriorating the performance of the eavesdropper. We derive expressions of the ergodic secrecy rate and the theoretical bit error rate upper bound. In addition, we analyze the case of imperfect channel estimation by taking practical concerns into consideration. It is shown via computer simulations that the proposed scheme outperforms the existing IM-based schemes and might be a candidate for future secure communication systems.