Physical Layer Secrecy Analysis Using Permutation Index-Based OFDM-DCSK System

Physical layer security (PLS) is a novel concept with strong influence that can support and possibly even replace encryption-based techniques. The primary objective of PLS is to take advantage of the physical properties of wireless communication channels and their limitations, such as noise, fading, interference, dispersion, diversity, etc., in a way that allows the intended user to recover data while prohibiting data recovery by eavesdroppers successfully. As a result, the fundamental concept of PLS is to use well-designed transmission systems to increase the performance disparity between a connection from Alice to a genuine receiver and a connection from Alice to an eavesdropper. This study examines the performance of PLS by constructing a new, highly secure, reliable, and efficient transmission system based on Differential Chaos Shift Keying (DCSK) and Permutation Index Orthogonal Frequency Division Multiplexing (PIM-OFDM) modulation. The performance of the PIM-OFDM-DCSK proposed system is investigated and tested under Additive White Gaussian Noise (AWGN) and multi-path Rayleigh fading channels (MRFC). In this paper, the secrecy capacity and secrecy outage probability are derived and analyzed for the proposed PIM-OFDM-DCSK and compared with PIM-DCSK and conventional DCSK over AWGN and MRFC. Our results demonstrate that the proposed PIM-OFDM-DCSK has better secrecy capacity and secrecy outage probability than PIM-DCSK and conventional DCSK modulation schemes.